ATCALS


________________________________________________________________________________________________________________________________________________
FINAL

Operational Requirements Document II (ORD)

HQ AFFSA (AFCC) 04-87

DoD Air Traffic Control and Landing Systems (ATCALS)

in the

National Airspace System (NAS)

ACAT Level Ic

___________________

HQ AFFSA/CC

OPR: HQ AFFSA/OL-W

Phone: Comm: (703) 614-7678

DSN: 224-7678

________________________________________________________________________________________________________________________________________________

OPERATIONAL REQUIREMENTS DOCUMENT

FOR

DoD ATCALS IN THE NAS

1. General Description of Operational Capability:

a. The DoD operates approximately 33% of all Air Traffic Control and Landing Systems (ATCALS) in the National Airspace System (NAS) in supporting both military and civil operations. Generally, military radar approach controls are located where there is a predominance of military operations and when mission requirements such as special use airspace or tactical training and development test and evaluation (DT&E) dictate. These military ATC facilities also provide the means to train and maintain a cadre of proficient radar approach controllers for worldwide deployment in support of the national interest. There is no overlap of responsibility between DoD and FAA within the NAS; therefore, DoD controllers and equipment must provide an equivalent level of service transparent to both military and civilian users. The United States Air Force is designated the lead DoD agency for this program.

b. As providers of approximately 22% of all air traffic control services to both civil and military aviation, the DoD is required to meet the national standards for air traffic services established by the FAA. The DoD currently provides these ATC services with a variety of ATCALS. To enable DoD air traffic control facilities to safely and expeditiously move aircraft to and from military and civil airfields and through the associated airspace, the system must be interoperable with FAA systems. The system must provide timely information and support necessary to accomplish safe separation requirements between aircraft, obstacles and from severe weather and accomplish expeditious and positive control of air traffic that originates/terminates in the controlled airspace delegated to the military. To accomplish the requirements listed above, the following basic capabilities must be provided:

(1) Electronic surveillance of airspace.

(2) Voice communications between pilots and controllers.

(3) Voice and data communications between controllers within a facility and between adjacent facilities.

(4) Process and exchange flight plan data between NAS facilities.

(5) Transmit and receive weather and airfield data.

(6) Monitor and control radio navigation aids and airfield lighting systems.

c. The NAS is an opportunity/obsolescence driven program. The FAA embarked upon a major upgrade of the NAS called the Capital Investment Plan (CIP), formerly called the NAS Plan. This multi-billion dollar initiative, begun in 1981, is dependent upon digital technology, automation, and some consolidation of radar air traffic control (ATC) facilities. Adoption of this strategy and technology was mandated by an increase in the demand for ATC services caused by deregulation, population growth and migration, selection by the public of flying as the transportation mode of choice, increased dependence of the nation's economy upon aviation, and approaching obsolescence of current ATCALS. Because the FAA is moving forward with a technology vastly different from that deployed, DoD must follow an equivalent course of action to ensure ATC functions carried on by the DoD/FAA will interface (maintain interoperability and compatibility) and adequately support the military and civilians as appropriate, mission. Although some of the systems depicted herein may have applicability to overseas theaters of operation, this document is designed to provide systems for use within the National Airspace System. However, the military controllers and the ATC services they provide constitute a DoD wartime readiness capability.

d. The Federal Aviation Act of 1958 mandates a civil/ military ATC system and places the responsibility on the FAA for oversight and control of the common system. In addition, the Memorandum of Agreement (MOA) between the DoD and FAA on the Future of Radar Approach Controls in the NAS, 14 Dec 88, states that the FAA "determines the standard for NAS equipment and ATC facilities" and that "DoD will equip facilities providing services to civil users so that the ATC service is transparent to the user." Changes in the national standards are occurring as the result of increased user demand on the NAS and the development of advanced automation and communications concepts. As specified in the FAA Capital Investment Plan, a series of programs to consolidate some ATC radar facilities into metropolitan ATC complexes is being implemented. Greatly increased levels of automation and digital technology enable this consolidation of facilities and provides controllers in both radar facilities and control towers with the ability to handle increased levels of traffic while offering several major safety enhancements. Therefore, FAA standards for providing ATC service have been revised and will be put into effect during the 1996≠2010 time frame.

e. For operational efficiency, flight safety, and to satisfy future aviation demands, DoD air traffic control equipment must possess a high operational availability and accommodate increases in air traffic and changing airspace configurations.

f. The Mission Need Statement (MNS) and Joint System Operational Requirements Document (JSORD), Air Traffic Control and Landing Systems (ATCALS) in the National Airspace System (NAS) were reviewed in preparation for Milestone 0. The MNS was found valid by the Joint Requirements Oversight Council. Direction was given to reformat the JSORD into an ORD IAW the new DoD 5000 series directive. This action ensures the maximum advantage is taken of the current acquisition strategy and the requirement is reviewed within the operational and fiscal environment. The JSORD was the official requirements document during Phase O, Concept Exploration and Definition and the Cost and Operational Effectiveness Analysis (COEA). Therefore, this document must be retained for COEA documentation.

2. Threat. This is not a threat driven program. In a 27 Nov 91 Memorandum, the Assistant Secretary of Defense/C3I determined the System Threat Assessment Report and Defense Intelligence Agency report were not required.

3. Shortcomings of Existing Systems:

a. The DoD ATCALS currently in use are approaching the end of their economic and technological life cycle. Consequently, these systems must be replaced or modified with service life extension programs and technical upgrades, or the capability to provide basic ATC services, support the military mission, and interoperate with the FAA will be significantly impaired. With few exceptions, most components were designed in the 1960s and first fielded in the mid≠to≠late 1970s. These systems were procured with a projected 20≠year life cycle. Some of the older components, like the AN/TPX≠42 ATC radar beacon system, were fielded prior to 1974 and have been modified several times to extend service life and to accommodate new operational requirements. Other components, such as the AN/GPN≠12 (ASR-7) surveillance radar, first fielded in the early 1970s, and the FSA≠52 communications control system, fielded in the early 1960s, are becoming difficult and increasingly more expensive to supply with repair parts. Without interim upgrades, nearly all components will be logistically not supportable by the year 2000. When these logistical problems are tied to the FAA's increased use of automation and advanced technology, the requirement to interoperate with the FAA's systems becomes even harder to meet.

b. There are several DoD programs underway which replace or modify ATCALS. These programs were approved prior to the publication of the NAS modernization plan and address specific logistic supportability issues. These programs will sustain operations in the interim until NAS modernization is complete. Programs include modification of insupportable Air Force, Army, and Navy radar automation system processors, life cycle extension of secondary/beacon radar sensors, purchase of commercially available primary surveillance radars to meet specific urgent mission requirements, planned procurement of microwave landing systems, and a Navy initiative to modify existing equipment to accept fiber optics.

4. Capabilities Required: For the DoD to fulfill its operational obligations to the NAS and FAA, and maintain controller proficiency to support wartime contingencies, it must modernize its current air traffic control voice, data and sensor systems. This modernization effort must provide interoperability with the FAA's ATC systems and ensure that civil and military operations, combat readiness training, and management of assigned airspace is supported, and not limited, by time consuming manual or verbal passing of data or interruptions in DoD ATC service due to equipment failures. Failure to keep pace with the FAA will impair DoD mission support and constrain the overall efficiency of the NAS. Failure to replace the DoD NAS will result in growing support costs and a system that is less capable than the national standard system now being put in place by the FAA. To achieve modernization, four DoD systems require modification/replacement: airport surveillance radars, secondary/beacon radars, facility automation, and communications switching equipment.

a. System Performance: To provide DoD with systems to perform the required ATC functions, a variety of equipment is needed:

(1) Digital Airport Surveillance Radar (DASR): Used to provide primary radar data to the DoD's radar approach controls, consolidated radar facilities, selected ground controlled approach facilities, and control towers. Some of the features the DASR must have are: clutter rejection, target accuracy, moving target detection, probability of detection, reliability, and maintainability equal to or better than that specified for the FAA's current generation airport surveillance radar (ASR-9). The following are DASR thresholds:

(a) The DASR is required to have an output signal able to support systems in a format compatible with the FAA's NAS radar network, Advanced Automation System, and fielded DoD radar display devices.

(b) The system must provide calibrated weather processing and reporting of intensity in accordance with the National Weather Service (NWS) 6 calibrated levels of intensity. The FAA standard for radar weather service is full 6-level weather detection and reporting calibrated according to NWS defined levels. The system must be capable of reporting two weather levels simultaneously with aircraft target processing and reporting. Weather updates must be provided every 60 seconds.

(c) With a beam elevation coverage of zero degrees to 30 degrees the DASR must be capable of providing surveillance coverage from surface to 20,000 feet AGL, 360 degree azimuth, and a range of 0.5 to 55 nautical miles from the radar site.

(d) The system must detect, with greater than or equal to 80% probability at 55 nautical miles, a one square meter radar cross section, Swerling 1 type target within line of sight coverage. Second time around targets, target loss due to blind speed, tangential courses, clutter areas, and attenuation should be eliminated.

(e) The subclutter visibility must be 42 dB or greater.

(f) System must have the capacity to process a total of 400 aircraft targets per scan plus 300 non-aircraft primary targets.

(g) The radar must have an average 10 or less false target reports per scan while meeting probability of detection thresholds.

(h) The radar response time must be adequate to conduct ASR approaches, radar vectoring, traffic alert, adherence to separation standards, and air traffic advisory operation. Response time must not exceed 0.8 seconds.

(i) The range accuracy error must not exceed Ī 1/32 nautical miles bias and 200 feet root mean squared (RMS) jitter (combined RMS 275 feet) for aircraft target with median signal to noise ratio (SNR) greater than 30 dB.

(j) The radar system must achieve an azimuth accuracy of 0.16 degrees RMS for aircraft target with median signal to noise ratio greater than 30 dB.

(k) Radar update rate must be 4.8 seconds (nominal).

(l) Operational availability must be 99.8%, or better, based on dual channel redundancy.

(m) The rotating antenna must withstand up to 85 knots sustained wind loading without requiring placement in the free-wheeling mode.

(n) Reliability. Mean Time Between Failures (MTBF) must not be less than 750 hours. Mean Time Between Critical Failures (MTBCF) must be no less than 3,400 hours.

(o) Maintainability. Mean Repair Time (MRT) must not exceed 1.0 hour. Mean Time to Restore System (MTTRS) must not exceed 6 hours for downing events. The Maximum Repair Time (MaxRT) must not exceed 3.0 hours to the 95th percentile. Built in Test/Fault Isolation (BIT/FI) detection rates must be 90%, or greater, down to an ambiguity group of three line replacement units (LRU) or less using automatic mode. BIT/FI detection rates must be 95%, or greater, down to one LRU using the automatic and manual mode. Troubleshooting, using all available means, must achieve 100% fault isolation capability for all failures not detected and fault isolated to a single LRU using BIT/FI. Scheduled maintenance must not take more than six hours per month, with no scheduled downtime.

(p) The DASR power will originate from commercial power with engine generator backup. Provisions must be incorporated in the system design to account for power surges and other anomalies associated with commercial and generator power sources. The radar system must prevent loss of critical data.

(q) The DASR must have a range resolution of 760 feet or better 80% of the time. The azimuth resolution must be 2.8 degrees 80% of the time.

(2) Secondary Surveillance Radar (SSR): Used to provide identity and altitude data to DoD radar approach controls, consolidated radar facilities, selected ground controlled approach facilities, and control towers. This system gives the controller a rapid and accurate means of correlating radar targets displayed on the screen with the flight plan data. Further, the beacon system provides rapid identification of aircraft in distress. It must provide aircraft surveillance information to the DoD advanced automation system (DAAS) for the purpose of target correlation, tracking and display. The following are secondary radar thresholds:

(a) The secondary radar system is required to be compatible with fielded FAA and DoD systems.

(b) With and elevation angle of zero degrees to 40 degrees the secondary radar system must be capable of covering a 360 degree azimuth from the surface to 60,000 feet AGL, and range of 120 nautical miles from the radar antenna.

(c) Radar update rate must be every 4.8 seconds (nominal).

(d) System must have the capacity to process a total of 400 aircraft targets per scan.

(e) Position accuracy must support all separation standards, radar vectoring, separation assurance (conflict alert/ AERA), and must have an azimuth accuracy RMS error of 0.26 degrees or less and range accuracy RMS error of 190 feet or less.

(f) The system probability of detection must be greater than or equal to 97.0%.

(g) System reliability must be able to sustain a MTBCF of 3,400 hours or greater.

(h) Operational availability must be 99.8% or better.

(i) MRT must not exceed 0.5 hours. The MaxRT must not exceed 1.5 hours to the 95th percentile, while the MTTRS must not exceed 6 hours for downing events. Built in Test/Fault Isolation (BIT/FI) detection rates must be 90% down to an ambiguity group of three LRUs or less using automatic mode and 95% down to one LRU using automatic and manual mode. On-site troubleshooting using all available means must achieve 100% fault isolation capability for all failures not detected and fault isolated to an LRU using BIT/FI. Scheduled maintenance must be no more than once per quarter, must not take more than 2 hours to complete, and must not require more than 0.5 hours of scheduled downtime.

(j) The secondary radar system power source will originate from commercial power with engine generator backup. Provisions must be incorporated in the system design to account for power surges and other anomalies associated with commercial and generator power sources. Backup for critical data is necessary.

(k) The secondary radar system must have a range resolution of 304 feet or better 80% of the time, and an azimuth resolution of 4.8 degrees or better 80% of the time.

(l) The secondary radar system must average no more than one false target per radar scan.

(m) The secondary radar antenna must withstand 85 knots sustained wind loading without placing the primary radar antenna in the freewheeling mode.

(3) DoD Advanced Automation System (DAAS): Used to receive and process both primary and secondary radar data, flight plan, weather and airport environmental data along with administrative information required for facility operations. To support stand-alone facilities which control/monitor activities in special use airspace, the automation system should be capable of transmitting all or portions of this processed data to a workstation/display remoted anywhere within the geographical control of the parent radar facility. New DoD automation systems must support at least the following configurations of ATC facilities: Large size facilities, which should be able to combine the approach control and special use airspace management functions from several locations into one facility; Medium size facilities, which serves primarily one military installation, with or without special use airspace; and a Small sized system designed to meet size and capability requirements of control towers with various workloads. Where a Large/Medium facility supports a military airfield, a single automation system may provide service to these facilities and control towers. All other towers should require dedicated systems. The system must process digital primary and secondary radar data from FAA/DoD long range and short range radars. The following are DAAS thresholds:

(a) The DAAS must be able to interface with fielded and future DoD/FAA systems. It must be able to automatically transfer aircraft position track data and flight plans between radar facilities within three seconds after operator input.

(b) The DAAS must have the capability to provide a mosaic radar presentation and selectively display any radar sensor and have single sensor display capability (not simultaneously on any display).

(c) The system must simultaneously display aircraft and two operator selectable levels of weather (contouring) intensity at each display position. The system should simultaneously display aircraft and six operator selectable levels of weather (contouring) intensity at each display position.

(d) The DAAS must accept supervisor request for facility information within 0.5 seconds. The mean response time to reassign airspace message must be no more than 5.0 seconds. The DAAS supporting each facility must be able to record automation data allowing playback of voice and automation data in a synchronized fashion for incident review and training critique. A mean system keyboard input response threshold is 250 milliseconds; 50 milliseconds or less is desirable.

(e) System keyboards must be equipped with variable intensity lighting to be visible and usable in all operational environments.

(f) The system must support the following number of workstations: Large - 50; Medium - 24; Small - 6.

(g) The system must display radar/beacon surveillance data in the following areas of coverage: Mosaic mode presentation, large facility - 250 X 400 nautical miles; medium facility - 150 X 200 nautical miles; single sensor mode - 60 nautical mile radius from the radar site.

(h) The system must have stand alone automatic tracking capability.

(i) The processors must have sufficient capacity for the following minimum number of target tracks for each type of facility: Large - 890; Medium - 250; Small - 250.

(j) Each system must capable of processing full data loads from the following number of long and short range radars: Large - 6 long range and 10 short range; Medium - 1 long range and 2 short range; Small - 1 short range.

(k) System operational availability must be 99.8% or greater.

(l) System MTBCF rate must be 5,000 hours or greater.

(m) MRT must not exceed 0.5 hours. MaxRT must not exceed 1.5 hours to the 95th percentile. MTTRS must not exceed six hours for downing event. Each system must have Built-In-Test/Fault Isolation (BIT/FI) detection rate capability of 90% down to an ambiguity group of three LRUs or less using automatic mode and a 98% detection rate down to one LRU using both automatic and manual mode. On-site troubleshooting using all available means must achieve a 100% fault isolation capability for all failures not detected and fault isolated to an LRU using BIT/FI. Scheduled maintenance must be no more than once per quarter. Scheduled maintenance must take no more than 2 hours to complete, and must require no more than 0.5 hours of scheduled downtime.

(n) The system must incorporate žfail softÓ and automatic failure mode recovery features to enable operation without interruption of essential services.

(o) Large and medium size automation systems must support the following number of satellite control towers: Large - 6, Medium - 4.

(p) Data processing time from radar detection to controller display must not exceed 1.5 seconds.

(q) The automation system must be able to route appropriate processed data to/from workstations within the facilities' area of responsibility (local) as well as to external (remote) facilities.

(r) System must interface with NAS air traffic management systems (i.e., NOTAMs, flight plan data, NAVAID, real time weather processor, and airfield status).

(s) System power supply will originate from an uninterruptible and conditioned power source that is not part of the automation equipment.

(t) Workstations and associated processors must support computer training scenarios and computer based instruction.

(u) System must accept flight plan entry/amendments, and electronically process flight information to control positions. Based on currently fielded system capacities, each facility must be able to process the following number of flight plans: large - 150, medium - 150, small - 75. (Note: The Army and Air Force will use electronic flight strips if available. The Navy's present and future ATC requirements do not call for the use of electronic flight strips.)

(v) The system must be able to process weather and airport environmental data in a selectable and timely manner.

(w) The system must be equipped with selectable (on/off/inhibit) stand-alone Conflict Alert processing.

(x) The system must be equipped with selectable (on/off/inhibit) stand-alone Minimum Safe Altitude Warning.

(y) Display accuracy precision is required to support ATC operations. The display must be able to depict information of interest with a relative accuracy of within 0.125 nautical miles or 0.4% of range of the position reported by the sensor system.

(4) Voice Switching System: Used to manage the voice communications of any ATC facility. The system must be modular in design to provide the needed flexibility. The following are DoD communications and control system thresholds:

(a) The DoD communications and control system must be interoperable with the FAA system.

(b) The system must support radar and control tower lighting environments (all operational environments).

(c) The system must provide an interface for recording all controller communications for analysis/training and sequencing with video equipment, if required.

(d) The system must provide an interface to DoD's digital and/or analog switch and distribution systems.

(e) System must have the capability to be reconfigured by first-line supervisors within 60 seconds, with no more than a 2 second interruption of service at any control position. The system should have the capability to reconfigure half of the circuits at a position while the system is handling 50% of peak communications traffic load within 15 seconds of issuing the command with no more than a 2 second interruption of service at any control position. Landline and radio frequencies must be transferable to any position.

(f) The system must have an operational availability of 99.8% or better.

(g) The system must have an MTBCF of 6,000 hrs or greater.

(h) MRT must not exceed 0.5 hours. MaxRT must not exceed 1.5 hours to the 95th percentile. MTTRS must not exceed 6 hrs for a downing event. Scheduled maintenance must be limited to once per quarter and require no more than two hours to complete, and must not require more than 0.5 hours of scheduled downtime. The system must be capable of automatic restart in prior configuration within one minute. Built in Test/Fault Isolation (BIT/FI) detection rates must be 90% down to an ambiguity group of three LRUs or less using automatic mode and 95% down to one LRU using automatic and manual mode. On-site troubleshooting using all available means must achieve 100% fault isolation capability for all failures not detected and fault isolated to an LRU using BIT/FI. There should be a dedicated maintenance position, and the system must automatically restart within 60 seconds.

(i) The system must have a minimum number of communications positions as follows: small facility - 9; medium facility - 36; large facility - 75. It must have the following number of UHF/VHF radios for controller access: small facility - 20; medium facility - 50; large facility - 100. It must support the following number of trunks/land lines: small facility - 30; medium facility - 50; large facility - 100. It must provide the following number of air-ground radios per position: small facility - 20; medium facility - 25; large facility - 30. It must support the following minimum interfaces per controller position (including intercom): small facility - 20; medium facility - 50; large facility - 50.

(j) The system power supply will originate from an uninterruptible and conditioned power source which is not part of the voice switch equipment. The voice switch must provide battery backup to sustain critical communication circuits.

(k) The system must connect any air to ground or ground to ground circuit after circuit selection to controller headset and microphone within 230 mseconds.

(l) The system must be electromagnetically compatible with other electronic equipment located at the facility.

b. Logistics and Readiness. NAS equipment and software is a combination of non-developmental and commercial off-the-shelf (COTS) items for CONUS-type fixed-base peacetime operations and is being procured by the FAA. Due to the nature of these operations, combat support requirements are not applicable. Where applicable, measures for operational availability and the frequency and duration of preventive or scheduled maintenance are specified in the system performance section of this document.

c. Critical System Characteristics: The equipment must be compatible with all other systems within the FAA NAS modernization. Where applicable, compatibility has been specified in the system performance section of this document. The equipment is neither required, nor expected, to operate in a nuclear, biological, or chemical environment. It does not require hardening from conventional or nuclear weapons. The system should have electromagnetic compatibility consistent with the DoD/FAA approach control environment. Since the system is a replacement for existing DoD equipment, it will not require security or safety measures above those currently employed by the services. The FAA is managing software development for the Advanced Automation System (AAS). There are two types of software being used in AAS; commercially developed software, and government developed application software. All application software is being developed in Ada and will be supported by the FAA for the life cycle of the system. DoD is procuring the AAS hardware and software on the FAA AAS contract. We expect the FAA will ensure sufficient controls exist to ensure total compatibility and single point responsibility for software design approval throughout the system life cycle.

5. Integrated Logistics Support (ILS). Logistics Support Analysis (LSA) should be an integral part of system engineering to effect development of logistic support, to identify needed support resources, and to plan for efficient acquisition of these resources.

a. Maintenance Planning. Maintenance of the NAS equipment should be as follows: On-Equipment (Remove and Replace) and Off-Equipment (Limited on-site, Depot, Contract, etc.). The system designs should allow for the use of BIT/BITE permitting the isolation, removal, and replacement of faulty LRUs during systems operations. Logistics must be considered for all aspects of the program including equipment selection, systems design, set≠up, installation, test, operations and maintenance. A capability to correct failures of hardware, firmware, and software should be required and in operation prior to the initial testing phase. An integrated FAA/DoD capability for software maintenance may be required. All of these considerations will be affected by the relationship of the DoD and FAA programs, and potential agreements for cooperative maintenance of common/related functions.

b. Support Equipment. Common support equipment already in the inventory should be used to the maximum extent possible. Peculiar support equipment and special tools will be acquired as necessary to support NAS related acquisitions. Peculiar equipment should be procured as part of these systems. Supply support and support equipment are required during the build phase of each contract with necessary equipment provisioning far enough in advance to allow for spares delivery prior to or concurrent with testing, equipment installation, and initial operating capability (IOC). Commonly supplied DoD supply items and consumables will be used whenever possible. Common LRUs and spare parts for more than one piece of equipment will be used whenever possible.

c. Human Systems Integration (HSI). Training and training support should be developed and available for use prior to operational test and evaluation (OT&E). Service specific training requirements, to include computer based instruction and simulation, should be developed in concert with the FAA and other services to the maximum extent possible. All systems procured should be evaluated for suitability of computer-human interface and safety features. The new systems must not create additional manpower authorizations, increased skill levels, or new military specialists to operate and maintain the equipment. The system should be easily maintained by technicians equivalent to U.S. Air Force skill level 5 using BIT diagnostics capabilities to the maximum extent possible. Formal technical "school house" training will be required to support this equipment.

d. Computer Resources. Each component of this program must be interoperable with and certified for use in the NAS. Maximum use will be made of NDI/COTS equipment, components and software. Specific automation efforts for each system are TBD. The software support agency must be functional by system IOC, and must provide for update, configuration control, and management of all computer programs and data. All software must be patch free with no unresolved critical problems prior to operational use. To allow for future software changes, each computer system procured under this program should have 50% computer reserve capacity and growth capabilities, which is consistent with FAA reserve capacity requirements. Quality and non proprietary software documentation and source code that facilitate software maintenance will be developed and delivered as part of each system. System acquisition must include all software support tools necessary to maintain and upgrade the software after the system is deployed. All software should support a user-friendly operations and maintenance environment. Criteria must be established for the timing of software upgrade cycles, if needed, prior to system acceptance.

e. Other Logistics Considerations. There are no unique logistical requirements identified at this time. Assessments of the FAA Capital Investment Plan are on-going and unique logistical requirements will be identified and coordinated. In determining the reliability factors for each system procured under this document, a reliability growth plan should be considered. Technical data and technical orders (TOs) must be procured with each system to support logistics requirements. Facilities and Land: The system (its intrinsic materials as well as its support requirements) must be supportable with regard to compliance with applicable international, federal, state and local environmental and human health regulations (e.g., the Clean Air Act, Resource Conservation and Recovery Act, the Montreal Protocol {Ozone Depleters}, etc.). All system materials and processes will be considered for incorporation into the system to minimize the threat. Strong consideration must be given to the protection of human health and the environment when selecting material that will result in the lowest cost over the complete cycle of the system. To identify all hazards and to eliminate or reduce the associated risk, an effective system safety program in accordance with a tailored version of MIL-STD-8882C should be fully integrated into all aspects of the acquisition effort as required by AFR 800-16. The appropriate environmental analysis will be accomplished IAW the National Environmental Policy Act (Public Law 91≠190). Land use and siting requirements will be identified, approved, and funded through the appropriate agency.

6. Infrastructure Support and Interoperability:

a. Command, Control, Communications, and Intelligence. Military ATC facilities support local military authority command and control requirements as well as NAS command and control needs during emergency and contingency situations. Dedicated command and control systems should operate in association with systems defined in this document. Interoperability should be maintained through application of appropriate electronic system standards. However, this document does not provide for dedicated command and control systems. ATC systems operating in the electromagnetic spectrum should meet the electromagnetic compatibility requirements in accordance with AFR 80-23. The NAS Joint Program Office is responsible for obtaining frequency allocations and assignments as required for the services.

b. Transportation and Basing. Site surveys to plan the facilities should be conducted once the equipment to be installed is known. Strong consideration should be given to use of existing facilities.

c. Standardization, Interoperability, and Commonality. DoD NAS systems are required to operate in a peacetime environment within the CONUS and U.S. territories. The envisioned operational environment is identical to current DoD CONUS facilities and companion FAA facilities. Facility designs should be standardized to the extent possible from a DoD≠wide perspective. However, as the FAA modernizes its ATC system, the DoD must modernize on a parallel effort to insure the unimpeded exchange of critical flight information/data among services and the FAA is maintained.

d. Mapping, Charting, and Geodesy (MC&G) Support. Standard DMA products will be used to the greatest extent possible. When standard DMA products cannot be used, MC&G requirements will be coordinated through AFSIA/INTB. WGS-84 is the Air Force standard datum and will be used. Cartographic information, required by the controllers, must be accepted for display by the DAAS. The capability to modify presented cartographic information must exist. The cartographic information requirements and modification capability requirements must be coordinated through AFSIA/INTB.

e. Environmental Support. Current weather data and forecast products are integral parts of the air traffic control system and critical to aviation safety. The DoD NAS system should be harmonized with current DoD weather sensors and forecasting systems, such as AWDS, NEXRAD, ASOS etc.

7. Force Structure. The modernization of the DoD's portion of the NAS revolves around the procurement of four major systems. These are the digital airport surveillance radar, a secondary/ beacon radar system, an advanced automation system for radar and tower facilities, and a voice communications switching system. Generally, the systems required by this document, when expressed by component subsystems, are required in the following numbers:

ESTIMATED QUANTITIES OF DoD NAS COMPONENTS BY TYPE

COMPONENT NUMBER REQUIRED NOTES
DIGITAL AIRPORT SURVEILLANCE RADAR 44 1,3
DoD ADVANCED AUTOMATION SYSTEM

TRAINING SYSTEMS

LARGE (MCF)

MEDIUM (LCF)

SMALL (MCT) OPS CONSOLES

MONITOR AND CONTROL CONSOLES

DATA SYSTEM SPECIALIST CONSOLES

TRAINING CONSOLES

AUXILIARY DISPLAYS

8

4

38

78

446

71

17

83

479

3






2

VOICE SWITCHING SYSTEM

(AIR FORCE & ARMY)

30 3,4

NOTES:

1. Figures do not reflect an Air Force requirement for the Keesler Tech Training Center.
2. Training consoles do not reflect pseudo or ghost pilot positions.
3. Does not reflect and state objective as modified by base closures.
4. Ancillary Radio Control Equipment must be acquired for the new MCFs.

8. Schedule Considerations. The DoD goal is to acquire NAS assets to meet the DoD/FAA Integrated Implementation Schedule. Current estimates, based on the FAA's projected modernization schedule, indicate the first modernization actions, to include IOC of DoD facilities will occur in the 1999 time frame. These actions will continue through the year 2004 (IOC/FOC TBD).

SIGNATURE

4 Atch

(See next page) 1. RCM (Parts I, II, III)

2. References

3. Points of Contact

4. Glossary

REQUIREMENTS CORRELATION MATRIX

PART I (Parametric Spreadsheet) As of Date:

DIGITAL AIRPORT SURVEILLANCE RADAR ORD I ORD II ORD III
SYSTEM CAPABILITIES AND CHARACTERISTICS THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE
1. Interoperability

a. DoD Format

b. FAA Format

Digital &

Analog

 
Yes

Yes


Yes

Yes

   
2. Weather Processing

a. Calibrated Levels

b. Levels Reported

c. Update (sec)

 
6

2


6

2

60


6

6

30

   
3. Coverage

a. Altitude (ft AGL)

b. Range (nm)

c. Azimuth (deg)

 

0-30,000

0.5-55



0-20,000

0.5-55

360


0-35,000

0.5-60

360

   
4. Probability of Detection   ≥90% 80% @ 55nm ≥90% @ 60nm    
* 5. Subclutter Visibility   ≥48 dB ≥42 dB ≥55 dB    
6. Capacity

a. Aircraft Targets

b. Non-Aircraft Targets

 
700

300


400

300


900

500

   
7. False Targets (avg/scan)   ≤1 ≤10 ≤1    
8. Response Time (sec)   ≤0.8 ≤0.8 ≤0.2    

9. Accuracy (RMS)

a. Range (ft)

b. Azimuth (deg)

 

275

0.16



275

0.16



275

0.16

   
10. Update Rate (sec)   Every 4 4.8 (nominal) Every 4    
11. Operational Availability   ≥99.9% ≥99.8% ≥99.9%    
12. Antenna Wind Bearing

Capability

  ≥80 kt w/o freewheel 85 kt w/o freewheel 85 kt w/o freewheel    
REQUIREMENTS CORRELATION MATRIX

PART I (Parametric Spreadsheet) As of Date:

DIGITAL AIRPORT SURVEILLANCE RADAR ORD I ORD II ORD III
SYSTEM CAPABILITIES AND CHARACTERISTICS THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE
13. Reliability

a. MTBF (hrs)

b. MTBCF (hrs)

 
≥750

≥5,000


≥750

≥3,400


≥1,500

≥10,000

   
14. Maintainability

a. MRT (hrs)

b. MTTRS (hrs)

c. MaxRT (hrs)

d. Fault Isolation / Detection

e. Scheduled Maintenance

f. BIT/FI

1) Auto

2) Auto and Manual

 

0.5

≤6.0

≤1.5

100%

Once/QTR, 2 hrs complete, ≤0.5 hrs downtime

≥90%

≥95%



≤1.0

≤6.0

≤3.0

100%

≤6.0 hrs/mo

with no

downtime

≥90%

≥95%



≤0.5

≤6.0

≤1.5

100%

<1.0 hr/mo

with no

downtime

≥90%

≥95%

   

15. Power Source

a. Primary/Backup


b. Prevent Data Loss

 


Conditioned / Uninter-ruptible



Commercial Power + Engine Generator Backup

Yes




Commercial Power + Engine Generator Backup

Yes

   
16. Resolution

a. Range (ft)

b. Azimuth (deg)

   
≤760

≤2.8


≤760

≤2.8

   
REQUIREMENTS CORRELATION MATRIX

PART I (Parametric Spreadsheet) As of Date:

SECONDARY

SURVEILLANCE RADAR

ORD I ORD II ORD III
SYSTEM CAPABILITIES AND CHARACTERISTICS THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE
1. Interoperability

a. DoD Format

b. FAA Format

Digital & Analog  
Yes

Yes

Mode S

Yes

Yes

   
2. Coverage

a. Altitude (ft AGL)

b. Azimuth (deg)

c. Range (nm)

 
60,000

360

250


60,000

360

120


60,000

360

200

   
3. Update Rate (sec)   Every 4 4.8 (nominal) Every 4 or 2 at selected locations    
4. Target Capacity

(per scan)

  700 400 900    
5. Accuracy (RMS)

a. Range (ft)

b. Azimuth (deg)

 
40

0.068


≤190

≤0.26


≤40

≤0.068

   
6. Probability of Detection   99.0% ≥97.0% ≥99.0%    
7. Reliability

MTBCF (hrs)

 
≥5,000

≥3,400

≥5,000
   

8. Operational Availability
 
99.9%

≥99.8%

≥99.9%
   
9. Maintainability

a. MRT (hrs)

b. MTTRS (hrs)

c. MaxRT (hrs)

d. Fault Isolation / Detection

e. Scheduled Maintenance

f. BIT/FI

1) Auto

2) Auto and Manual

 
≤0.5

≤6.0

≤1.5

100%

Once/QTR, 2 hrs complete, ≤0.5 hrs downtime

≥90%

≥95%


≤0.5

≤6.0

≤1.5

100%

Once/QTR, 2 hrs complete, ≤0.5 hrs downtime

≥90%

≥95%


≤0.5

≤6.0

≤1.5

100%

Once/QTR, 2 hrs complete, ≤0.5 hrs downtime

≥90%

≥95%

   
10. Power Source

a. Primary/Backup

b. Prevent Data Loss

 
Conditioned /Uninter-ruptible

Commercial Power + Engine Generator Backup

Yes


Commercial Power + Engine Generator Backup

Yes

   
11. Resolution

a. Range (ft)

b. Azimuth (deg)

   
≤304

≤4.8


≤190

≤2.35

   
12. False Targets (Avg/Scan)     ≤1 ≤1    
13. Antenna Wind Bearing

Capability

    85 kt w/o freewheel 85 kt w/o freewheel    
REQUIREMENTS CORRELATION MATRIX

PART I (Parametric Spreadsheet) As of Date:

DoD ADVANCED

AUTOMATION SYSTEM

ORD I ORD II ORD III
SYSTEM CAPABILITIES AND CHARACTERISTICS THRESHOLD
OBJECTIVE THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE
1. Inter/Intrafacility Data

Transfer

*a. Auto transfer of

position track data

between facilities

*b. Electronic

interfacility transfer

of flight plans

*c. Interface with

existing / future

FAA/DoD ATC

systemsNote: * for žcÓ is white color text

   

IAW ICD

IAW ICD

Yes



IAW ICD

IAW ICD

Yes

   
2. Radar Presentation Mosaic / Sel.   Mosaic / Sel. Use all inputs to support track    
3. Display Weather Levels (simultaneously with aircraft)   2 Simultaneous display of 2 reported levels Simultaneous display of 6 reported levels    
4. Facility Configuration

a. Supervisory facility configuration display

 

≤0.5 sec

≤0.5 sec
   
b. Reassign airspace to controller positions (mean) c. Recording, playback, archiving, printout of operations and systems data

d. Keyboard input Response

  Within 5 sec ≤5.0 sec

Support synchronized recording of voice/data

≤250 msec

≤5.0 sec

Support synchronized recording of voice/data

≤50 msec

   
5. Controller Position Visibility     All operational environments All operational environments    
6. Workstations

Supported

  MCF: 50

LCF: 24

MCT: 6

Large: 50

Medium: 24

Small: 6

Large: 50

Medium: 24

Small: 6

   
7. Radar / Beacon Surveillance Data Presentation (nm)

a. Mosaic Mode

1) Large

2) Medium

b. Single Sensor Mode

 

200 X 400

120 (radius)

60 (radius)



250 X 400

150 X 200

60 (radius)



500 X 800

200 X 400

60 (radius)

   
8. Stand-Alone Automatic Tracking   Auto / Semi Yes Yes    
REQUIREMENTS CORRELATION MATRIX

PART I (Parametric Spreadsheet) As of Date:

DoD ADVANCED

AUTOMATION SYSTEM

ORD I ORD II ORD III
SYSTEM CAPABILITIES AND CHARACTERISTICS THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE
* 9. Aircraft Tracked   MCF: 1,000

LCF: 270

MCT: 250

Large: 890

*Med: 250

Small: 250

Large: 3,170

Med: 900

Small: 300

   
10. Radar Capacity

a. Large (MCF)

b. Medium (LCF)

c. Small (MCT)

 
5 LRR, 10 SRR

2 LRR, 4 SRR

0 LRR, 1 SRR


6 LRR, 10 SRR

1 LRR, 2 SRR

0 LRR, 1 SRR


6 LRR, 10 SRR

2 LRR, 4 SRR

0 LRR, 1 SRR

   
11. Availability   99.9% ≥99.8% ≥99.9%    
12. System Reliability

MTBCF (hrs)

  ≥5,000 ≥5,000 ≥12,000    
13. Maintainability

a. MRT (hrs)

b. MTTRS (hrs)

c. MaxRT (hrs)

 
0.5

≤6.0

≤1.5


≤0.5

≤6.0

≤1.5


≤0.5

≤6.0

≤1.5

   
d. Fault Isolation / Detection e. Scheduled Maintenance

f. BIT/FI

1) Auto

2) Auto and

Manual

  100%

Once/QTR, 2 hrs complete, ≤0.5 hrs downtime

≥90%

≥95%

100%

Once/QTR, 2 hrs complete, ≤0.5 hrs downtime

≥90%

≥98%

100%

Once/QTR, 2 hrs complete, ≤0.5 hrs downtime

≥95%

≥99%

   
14. Failure Recovery (sec)   ≤30 Fail Soft / Automatic Fail Soft / Automatic    
15. Towers Supported   MCF: 6

LCF: 4

Large: 6

Medium: 4

Large: 6

Medium: 6

   
16. Data Processing Delay (sec)   ≤1.5 ≤1.5 ≤1.5    
17. Route Processed Data   wkst/fac Local/Remote Local/Remote    
18. System Interface   NAS mgt system NAS mgt system NAS mgt system    
19. Power Source
 
Conditioned/ Uninter-ruptible

Conditioned/ Uninter-ruptible

Conditioned/ Uninter-ruptible
   
REQUIREMENTS CORRELATION MATRIX

PART I (Parametric Spreadsheet) As of Date:

DoD ADVANCED

AUTOMATION SYSTEM

ORD I ORD II ORD III
SYSTEM CAPABILITIES AND CHARACTERISTICS THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE
20. Workstations / Processors   Support computer training Support computer training Support computer training    
21. Flight Movement Support

a. Accept flight plan entry / amendment

b. Elec. process flight information to control positions

c. Flight plans processed

 
MCF: 1,500

LCF: 750

MCT: 250

Yes

Yes

Large: 150

Med: 150

Small: 75

Yes

Yes

Large: 1,500

Med: 750

Small: 250

   
22. Display Weather and Airport Environmental Data     Yes / Selectable Yes / Selectable    
23. Stand-Alone Conflict Alert Processing     Yes / Selectable Yes / Selectable    
24. Stand-Alone MSAW Processing     Yes / Selectable Yes / Selectable    
25. Display Accuracy (nm)     ≤0.125 or ≤0.4% of range ≤0.005    
REQUIREMENTS CORRELATION MATRIX

PART I (Parametric Spreadsheet) As of Date:

VOICE COMM

SWITCHING SYSTEM

ORD I ORD II ORD III
SYSTEM CAPABILITIES AND CHARACTERISTICS THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE
* 1. Interoperability FAA Sys   Interface to existing FAA Systems Digital Voice Systems    
2. Lighting

a. Radar Room

b. Control Tower


Yes

Yes

 
All operational environments

All operational environments
   
3. Voice Recording Interface All voice interfaces   All voice communi-cations All voice communi-cations    
4. System Interface Capability Digital / Analog   Interface w/DoD Systems Interface w/DoD Systems    
5. Reassign Frequencies and Voice Channels to Controller Positions (sec)   30 ≤60 ≤15    
6. Operational Availability   99.9% ≥99.8% ≥99.9%    
7. Reliability MTBCF (hrs)   ≥8,000 ≥6,000 ≥8,000    
8. Maintainability

a. MRT (hrs)

b. MTTRS (hrs)

c. MaxRT (hrs)

d. Fault Isolation / Detection

e. Scheduled Maintenance

f. Automated BIT/FI

1) Auto

2) Auto and Manual

g. Automatic Restart

 
0.5

≤6.0

≤1.5

100%

Once/QTR, 2 hrs complete, ≤0.5 hrs downtime

≥90%

≥95%

Within 15 sec


≤0.5

≤6.0

≤1.5

100%

Once/QTR, 2 hrs complete, ≤0.5 hrs downtime

≥90%

≥95%

Within 60 sec


≤0.5

≤6.0

≤1.5

100%

Once/QTR, 2 hrs complete, ≤0.5 hrs downtime

≥90%

≥95%

Within 60 sec

   
9. Number of Comm Positions   MCF: 75

LCF: 24

MCT: 8

Large: 75

Med: 36

Small: 9

Large: 75

Med: 36

Small: 9

   
10. Number of UHF/VHF Radios   MCF: 100

LCF: 50

MCT: 20

Large: 100

Med: 50

Small: 20

Large: 100

Med: 50

Small: 20

   
REQUIREMENTS CORRELATION MATRIX

PART I (Parametric Spreadsheet) As of Date:

VOICE COMM

SWITCHING SYSTEM

ORD I ORD II ORD III
SYSTEM CAPABILITIES AND CHARACTERISTICS THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE THRESHOLD OBJECTIVE
11. Number of Telephone Lines   MCF: 100

LCF: 50

MCT: 30

Large: 100

Med: 50

Small: 30

Large: 100

Med: 50

Small: 30

   
12. Number of A/G Radios Per Position   MCF: 50

LCF: 30

MCT: 20

Large: 30

Med: 25

Small: 20

Large: 30

Med: 25

Small: 20

   
13. Number of Interfaces Per Position   MCF: 50

LCF: 50

MCT: 20

Large: 50

Med: 50

Small: 20

Large: 50

Med: 50

Small: 20

   
14. Power Source

a. Primary/Backup

b. Sustain Critical Circuits

  Conditione/ Uninter-ruptible Conditioned/ Uninter-ruptible

Yes

Conditioned/Uninte-rruptible

Yes

   
15. Connect A/G or G/G Lines     Establish duplex connection within 230 msec Establish duplex connection within 230 msec    
16. Electromagnetic Compatibility (EMC)     Yes Yes    

RCM PART II:

REQUIREMENTS CORRELATION MATRIX

Part II

(Supporting Rationale for System Characteristics & Capabilities)

AS OF DATE:

DIGITAL AIRPORT SURVEILLANCE RADAR

Parameter 1: Interoperability. The primary radar output format must be compatible with fielded DoD radar display devices. The primary radar output format must be compatible with the FAA's automation system input format. To support ATC mission needs the primary radar must be compatible with the FAA automation system.

Parameter 2: Detect Weather Levels. The primary radar must detect and process the National Weather Service's 6 calibrated levels of weather intensity. Six level weather processing is required to provide FAA-equivalent weather surveillance service. The FAA standard for radar weather service is full 6-level weather detection and reporting, calibrated according to National Weather Service defined levels. At a minimum, 2 levels must be reported simultaneously. Weather updates must occur at minimum every 60 seconds; preferred every 30 seconds.

Parameter 3: Coverage. To support terminal area ATC operations, azimuth coverage of 360 degrees, up to 20,000 feet AGL minimum, and range coverage from 0.5 to 55 nautical miles (for a beam elevation coverage zero to 30 degrees), is required.

Parameter 4: Probability of Detection. To receive basic ATC services, aircraft entering the controller's area of responsibility must be reliably detected. Existing primary radars which detect a one square meter Swerling 1 type target (F-16 size aircraft) at 55 nautical miles with 80% probability in the clear provide an acceptable level of service. Pd levels below 80% degrade the ATC system ability to detect and track aircraft based on primary radar target reports.

Parameter 5: Subclutter Visibility. The primary radar must be able to detect moving targets imbedded in clutter. SCV levels below 42 dB greatly diminish the primary radar system's ability to detect aircraft in clutter within the coverage volume and are unacceptable.

Parameter 6: Capacity. Based on current and projected traffic densities at DoD ATC facilities, the primary radar system must process minimum 400 aircraft targets and 300 non-aircraft targets.

Parameter 7: False Targets. More than 10 reports per scan will decrease the system's ability to properly track aircraft targets. The number of false targets must average no more than 10 per radar scan.

Parameter 8: Response Time. The primary radar must process target data in a timely fashion or aircraft position data appearing on the controllers displays will not reflect the true real time aircraft position. The FAA standard for radar data processing response time is <0.8 seconds.

Parameter 9: Accuracy. The primary radar must provide sufficient range and azimuth accuracy to support terminal ATC separation standards. Current state-of-the-art radars provide a range accuracy of 275 feet RMS and azimuth accuracy of 0.16 degrees RMS which is adequate to support terminal area ATC separation requirements.

Parameter 10: Update Rate. Current primary radars provide aircraft detection updates at intervals of 4.8 seconds which is adequate to support terminal area ATC requirements.

Parameter 11: Operational Availability. Current upgraded primary radars provide an operational availability of 99.8% which is adequate to support terminal area ATC operations.

Parameter 12: Antenna Wind Bearing Capability. The radar must perform adequately when the antenna is subjected to sustained wind speeds of up to 85 knots to support all ATC operational environments.

Parameter 13: Reliability. Current primary radar is a dual channel radar with a mean time between failure (MTBF) of >750 hours and mean time between critical failures (MTBCF) of 3,400 hours. This capability must provide a 99.8% operational availability to support terminal ATC operations.

Parameter 14: Maintainability. To meet the operational requirements for continuous ATC support, the mean repair time (MRT) must not exceed 1.0 hour (excludes administrative and logistics delay times); with a mean time to restore system (MTTRS) not to exceed 6 hours (includes administrative and logistics delay time). Sparing levels must be established to support the 6 hour MTTRS. The maximum repair time (MaxRT) is based on the repair times following a Log-normal distribution, where 95% of the repair times will fall within three times the MRT or 3.0 hours. The system must be able to perform built-in-test (BIT) and fault isolation at a level that will support the 1.0 hour MRT. BIT/FI detection of not less than 90% of the detected failures down to three LRUs using automatic BIT/FI, 95% of the detected failures down to one LRU using both automatic and manually initiated BIT/FI and 100% of all detected failures using all methods, i.e., automatic, manual, and external support equipment is required. This will ensure timely corrective maintenance and minimum impact on flight operations. To achieve the stated operational availability, scheduled maintenance must be no more than 6.0 hours per month with no scheduled downtime.

Parameter 15: Power Source. FAA Order 6950.2C, Electrical Power Policy, states that backup electrical power is required in NAS facilities to ensure continued service in the event of primary power outages. The system will be serviced from commercial power with engine generator backup and must have provisions to accommodate surges and other anomalies. The radar system itself must have provisions to prevent critical data loss.

Parameter 16: Resolution. To ensure adequate discrimination between closely spaced targets in the radar coverage area, the primary radar must provide acceptable range and azimuth resolution. The range resolution of the primary radar must be 760 feet or less 80% of the time. The azimuth resolution must be 2.8 degrees or less 80% of the time.

SECONDARY SURVEILLANCE RADAR

Parameter 1: Interoperability. The secondary radar output format must be compatible with fielded DoD systems. The secondary radar output must be compatible with fielded FAA automation system formats. DoD format is necessary to support the transition from fielded systems to the new automation system.

Parameter 2: Coverage. The secondary surveillance radar must provide azimuth coverage of 360 degrees, distance of 120 nautical miles from the radar site, up to 60,000 feet AGL, and beam elevation coverage of 0 to 40 degrees, to accommodate DoD unique operations.

Parameter 3: Update Rate. Based on current systems, the nominal radar update rate must be 4.8 seconds to support ATC mission requirements.

Parameter 4: Target Capacity. Based on the anticipated increase in traffic a minimum target capacity of 400 targets is required to support ATC mission requirements.

Parameter 5: Accuracy. The secondary surveillance radar must provide sufficient range and azimuth accuracy to support terminal ATC separation standards. The system must provide a range accuracy RMS error of 190 feet or less and azimuth accuracy RMS error of 0.26 degrees or less.

Parameter 6: Probability of Detection. To receive basic ATC services, aircraft entering the controllers' area of responsibility must be reliably detected. A probability detection of ≥97.0% supports mission requirements.

Parameter 7: Reliability. The mean time between the critical failures must be commensurate with required operational availability. Current secondary surveillance radars provide a mean time between critical failure of ≥3,400 hours. This, along with the stated maintainability parameters, supports operational availability requirements.

Parameter 8: Operational Availability. To support 24 hour per day ATC operations the secondary surveillance radars must provide an operational availability of ≥99.8% which is adequate to support terminal area ATC operations.

Parameter 9: Maintainability. To meet the operational requirements for continuous ATC support, the mean repair time (MRT) will not exceed 0.5 hours (excludes administrative and logistics delay times); with a mean time to restore system (MTTRS) not to exceed 6 hours (includes administrative and logistics delay time). Sparing levels must be established to support the 6 hour MTTRS. The maximum repair time (MaxTR) is based on the repair times following a Log-normal distribution, where 95% of the repair times will fall within three times the MRT or 1.5 hours. The system must be able to perform built-in-test (BIT) and fault isolation at a level that will support the 0.5 hour MRT. BIT/FI detection of no less than 90% of the detected failures down to three LRUs using automatic BIT/FI, 95% of the detected failures down to one LRU using both automatic and manually initiated BIT/FI and 100% of all detected failures using all methods, i.e., automatic, manual and external support equipment is required. This will ensure timely corrective maintenance and minimum impact on flight operations. To achieve the stated operational availability, quarterly scheduled maintenance of 2 hours duration must not cause system downtime to exceed 0.5 hours.

Parameter 10: Power Source. FAA Order 6950.2C, Electrical Power Policy, states that backup electrical power is required in NAS facilities to ensure continued services in the event of primary power outages. The system will be serviced from commercial power with engine generator backup and must incorporate provisions to accommodate surges and other anomalies. The system itself must have provisions to prevent critical data loss.

Parameter 11: Resolution. To ensure adequate discrimination between two closely separated targets in the radar coverage area, the secondary surveillance radar must provide, at minimum, a range resolution of 304 feet 80% of the time, and azimuth resolution of 4.8 degrees 80% of the time.

Parameter 12: False Targets. The secondary radar must produce an average of no more than one false target per radar scan to ensure controllers do not mis-identify an aircraft under their control.

Parameter 13: Antenna Wind Bearing Capability. The secondary radar must perform adequately when the antenna is subjected to sustained wind speeds of 85 knots to support all ATC operational environments.

DoD ADVANCED AUTOMATION SYSTEM (DAAS)

Parameter 1: Inter/Intrafacility Data Transfer. The system must be capable of automatic transfer of position track data between radar facilities to establish a track in the receiving facility. Track information includes track identification, track position, and track velocity. Electronic interfacility transfer of Instrument Flight Rule (IFR) and Visual Flight Rule (VFR) flight plans for controller and selected automation functions is required. Informational data includes aircraft departures, arrivals, or transitory aircraft flying through the radar facility airspace. Automation data provides for automatic tracking, route processing, and posting of aircraft movement. NAS-MD-601 and NAS-MD-610 identify the message format and functionality requirements for inter facility data transfer. The time for processing the operator input must be 3.0 seconds or less. The FDIO functional specification (NAS-MD-580) and software interface control document (NAS-MD-581) provide the minimum requirements for electronic inter facility transfer of IFR and VFR flight plans. The system must also interface with fielded and future DoD/FAA systems.

Parameter 2: Radar Presentation. Mosaic radar data is required in some large facilities, enroute, and Military Assumes Responsibility for Separation of Aircraft (MARSA) operations areas to provide sufficient surveillance volume coverage. Single sensor display capability is required to use three (3) mile separation standards in the terminal environment.

Parameter 3: Display Weather Levels. The system must display two user selectable levels of weather intensities simultaneously with aircraft targets. A minimum of two levels of weather are required to assist the controller in select an appropriate display among the six processed weather levels.

Parameter 4: Facility Configuration. Reassignment of airspace to controller positions is required to support facility configurations due to shift workloads, equipment failure, and special mission support. Data recording, archiving, playback (synchronized voice/data), and printout of critical ATC data (operational and system configuration) is required to support aircraft incident, accident investigation, search and rescue, and controller training. Mean response time for an airspace reassignment message is to be 0.5 seconds or less. Based on industry survey of fielded automation systems, a mean keyboard input response time of ≤250 msec is required.

Parameter 5: Controller Position Visibility. Because lighting requirements may differ between ATC facilities, variable intensity keyboard lighting is required for the controller to see and use the keyboard. Keyboards must be visible and usable in all operational environments.

Parameter 6: Workstations Supported. The number of workstations supported is determined by the operations supported by the facility. DoD has three sizes of facilities to be supported: Large - up to 50 workstations, Medium - up to 24 workstations, Small - up to 6 workstations. Workstation quantities reflect the maximum number of controller (radar and data), supervisor, maintenance, and training positions required to support the facility mission.

Parameter 7: Radar/Beacon Surveillance Data Presentation. Radar data presentation is required to provided surveillance volume sensor coverage due to geographical or operational constraints in support of terminal, en-route, and MARSA operations. For facilities operating in the Mosaic mode, the required area of coverage for a large size facility is 250 X 400 nautical miles; the required area of coverage for a medium size facility is 150 X 200 nautical miles. For facilities operating in the single sensor mode, coverage of 60 nautical mile radius is required for display of a single radar supporting terminal approach radar, GCA, and IFR tower ATC requirements.

Parameter 8: Stand-Alone Automatic Tracking. Stand Alone Automatic tracking is an autonomous function that supports auto-acquire, heading/altitude/velocity calculations and predictions, and hand-off functions. These tracking functions must support those used by the FAA for system interoperability. NAS-MD-321 provides guidelines for automatic tracking.

Parameter 9: Aircraft Tracked. The large facility value of 890 tracks is calculated based on six long range radars and ten short range radars operating with 75% overlapping coverage. The value of 250 tracks for a medium facility is calculated based on one long range radar and two short range radars operating with 75% overlapping coverage. The value of 250 tracks for a small size radar facility is based on a single short range radar.

Parameter 10: Radar Capacity. Large size facilities require radar capacity of six long range radars and ten short range radars, medium size facilities require one long range and two short range radars for display of multiple terminal ATC airspace volumes associated with special use airspace volume coverage. One short range radar is required for terminal (small) operations.

Parameter 11. Availability. The operational availability for the DAAS must be 99.8%. This ensures that air traffic control (ATC) services continue uninterrupted.

Parameter 12: System Reliability. The mean time between critical failures (MTBCF) for the system must be not less than 5,000 hours. This, along with the maintainability parameters will support the operational availability objectives of 99.8%

Parameter 13: Maintainability. To meet the operational requirements for continuous ATC support, the mean repair time (MRT) will not exceed 0.5 hours (excludes administrative and logistics delay times); with a mean time to restore system (MTTRS) not to exceed 6 hours (includes administrative and logistics delay time). Sparing levels must be established to support the 6 hour MTTRS. The maximum repair time (MaxTR) is based on the repair times following a Log-normal distribution, where 95% of the repair times will fall within three times the MRT or 1.5 hours. The system must be able to perform built-in-test (BIT) and fault isolation at a level that will support the 0.5 hour MRT. BIT/FI detection rate of not less than 90% of the detected failures down to an ambiguity group of three LRUs, 98% detection rate down to one LRU using both automatic and manual modes, and 100% of the detected failures using all available methods. This will ensure timely corrective maintenance and minimum impact on flight operations. To achieve the stated operational availability, quarterly scheduled maintenance must take no more than 2 hours to complete, and must require no more than 0.5 hours of scheduled downtime.

Parameter 14: Failure Recovery. The DAAS is required to be very reliable with a high system availability. It is recognized, however, that hardware and software failures may occur which could prevent the system from performing all designated functions. Therefore, two levels of system functional capability have been defined. In the Full-Service Mode, the DAAS performs all designated functions within the required response times. In the event that this level of functional performance cannot be maintained, a "fail-soft" or Emergency Mode of operation is defined. In the Emergency Mode, the most essential services of surveillance, automatic tracking, and local flight data update are provided. The Emergency Mode is intended primarily to provide continuity of essential services during a transition to Facility Backup or a return to Full-Service. The system must support planned and unplanned automatic transitions between these modes of operation.

Parameter 15: Towers Supported. To support the new DoD radar approach control architecture which calls for providing ATC services to multiple airports from a single radar facility, the automation system for large and medium size approach controls must also support the systems for six towers and four towers respectively. For optimum flexibility, both large and medium size radar facilities should be capable of supporting six control towers.

Parameter 16: Data Processing Delay. System configuration, alerts, emergency data must be displayed with minimum delay. A time of 1.5 seconds or less is the FAA maximum value for critical ATC information data processing delay in accordance with NAS-SS-1000.

Parameter 17: Route Processed Data. Dissemination of ATC information entered locally on a controller/supervisor workstation or processed by the system must be available to any user of the system, local (within the facility) or remote facility. The controller must be able to manually or automatically route data to other users with minimum delay. Critical ATC data and supervisor messages shall have priority.

Parameter 18: System Interface. The ability to interface and process input and output data from air traffic management systems such as the NOTAM processor, NEXRAD, Traffic Management Unit, are required.

Parameter 19: Power Source. FAA Order 6950.2C, Electrical Power Policy. The order states that backup electrical power is required in NAS facilities to ensure continued service in the event of primary power outages. The automation system must be serviced from a conditioned and uninterruptible power source.

Parameter 20: Workstations/Processors. Workstations and processors must support controller proficiency training, both scenario generated and computer based to provide a cost effective, low risk vehicle for controller training.

Parameter 21: Flight Movement Support. All flight progress information must be accepted by the ATC system. The system must electronically process flight information, from internal and external sources at control positions. The system must electronically process 150 flight plans for large and medium size facilities and 75 flight plans for small size facilities. (Note: If electronic strips are available, the Air Force and Army plan to use this capability. Future Navy ATC requirements will not include the use of electronic flight strips.)

Parameter 22: Display Weather and Airport Environmental

Data. Weather alerts, weather warnings and advisories, observations, terminal aerodrome forecasts, runway conditions, braking action reports, inoperable airfield equipment, and supervisor configurations must be selectively displayed and processed.

Parameter 23: Stand-Alone Conflict Alert Processing. Conflict alert processing is a required safety feature to predict when two tracked targets may lose required separation. System must have the capability to select (on/off/inhibit) conflict alert within a facility airspace (i.e., approach and departure ends of runway) to avoid false alarms. NAS-MD-632 provides guidelines for Conflict Alert processing.

Parameter 24: Stand-Alone Minimum Safe Altitude Warning

(MSAW) Processing. Minimum Safe Altitude Warning processing is required for terminal and enroute ATC facilities to predict when tracked targets may descend unacceptably close to the ground or areas of rising terrain. System must have the capability to select (on/off/inhibit) MSAW within a facility airspace (i.e., approach and departure ends of runway) to avoid false alarms. NAS-MD-644 provides guidelines for MSAW processing.

Parameter 25: Display Accuracy. Portrayal of the relative position of aircraft on the display must be very accurate to enable the controller to ensure separation between aircraft. The display accuracy to be achieved is ≤0.125 nautical miles or ≤0.4% of range.

VOICE COMMUNICATIONS CHARACTERISTICS

Parameter 1: Interoperability. System must interface with existing analog and planned digital FAA communication systems. DoD facilities must be able to accept control of civilian aircraft entering DoD airspace and must be able to transfer military aircraft to FAA control upon leaving DoD controlled airspace. Ground-to-Ground interfaces are per FAA NAS Interface Control Document NAS-IC-42028403 Tower Communications Switching System (TCS) and Integrated Communications Switching System (ICSS) to Existing Ground-to-Ground Voice Communications Trunks, January 1990. PSTN/FTS interface to the Public Switched Telephone Network or Federal Telecommunications System per BELLCORE TR-NPL-000275 Notes on the BOC Intra-LATA Networks - 1986. System must provide digital interface capability per NAS-IR-43004405 at large ATC facilities.

Parameter 2: Lighting. The controller must be able to clearly view and discern the labels and indicators on the voice switch control panels with ambient light ranging from full darkness to bright sunlight directly on the panel (all operations environments).

Parameter 3: Voice Recording Interface. According to FAA regulations, the system is required to continuously record all controller voices and all incoming voice signals heard by the controller. The voice switch shall provide connectivity to the legal recorders for all A/G and G/G transmissions and receptions to and from each control position.

Parameter 4: System Interface Capability. The system must interface with existing analog DoD voice equipment and circuits, aircraft using Air/Ground radios, and with all other positions within the DoD facility as required. According to FAA NAS Interface Requirements Document NAS-IR-42009404 Voice Switch/Private Automatic Branch Exchange, June 1987, PABX shall interface with local voice circuits. Air/Ground radio interface with DoD Air/Ground radios is required per FAA NAS Interface Control Document NAS-IC-42028401 Tower Communications Switching System (ICSS) to Existing Radio Equipment, January 1990. Any position connected to the voice switch must be able to interface with all other positions on the same voice switch.

Parameter 5: Reassign Frequencies and Voice Channels to Controller Positions. The system should provide the capability to reassign any mix of available site frequencies and voice lines to each controller position. All positions in a large facility must be reconfigurable during peak communications traffic load, within 60 seconds of issuing the command with no more than a 2 second interruption of service at any control position. The system should have the capability to reconfigure half of the circuits at a position while the system is handling 50% of peak communications traffic load within 15 seconds of issuing the command with no more than a 2 second interruption of service at any control position.

Parameter 6: Operational Availability (Ao). Operational availability of ≥99.8% must support mission requirements. This operational availability is based on the reliability and maintainability parameters below.

Parameter 7: Reliability. Mean time between critical failure (MTBCF) must be not less than 6,000 hours. This threshold is based on existing equipment and will support the operational availability (Ao) of ≥99.8%. Reliability objective of 8,000 or more hours will support an operational availability of ≥99.9%.

Parameter 8: Maintainability. To meet the operational requirements for continuous ATC support, the mean repair time (MRT) will not exceed 0.5 hours (excludes administrative and logistics delay times), with a mean time to restore system (MTTRS) not to exceed 6 hours (includes administrative and logistics delay time). Sparing levels must be established to support the 6 hour MTTRS. The maximum repair time (MaxTR) is based on the repair times following a Log-normal distribution, where 95% of the repair times will fall within three times the MRT or 1.5 hours. The system must be able to perform built-in-test (BIT) and fault isolation at a level that will support the 0.5 hour MRT. Built in Test/Fault Isolation (BIT/FI) detection rates must be 90% down to an ambiguity group of three LRUs or less using automatic mode and 95% down to one LRU using automatic and manual mode. On-site troubleshooting using all available means must achieve 100% fault isolation capability for all failures not detected and fault isolated to an LRU using BIT/FI. This will ensure timely corrective maintenance and minimum impact on flight operations. To achieve the stated operational availability, the scheduled maintenance of once per quarter and two hours to complete will not cause system downtime to exceed 0.5 hours per quarter. There should be a dedicated maintenance position, and the system must automatically restart within 60 seconds.

Parameter 9: Number of Comm Positions. Each control position must be modular so that a station can be configured to provide any mix of capabilities, within the quantity requirements specified per position, without redesign. The total system shall be capable of supporting the maximum specified number of positions, each configured with the maximum number of interfaces and carrying a full voice traffic load. Three sizes of expandable voice switches are required: large facility - 75 comm positions, medium size facility - 36 comm positions, small facility - 9 comm positions.

Parameter 10: Number of UHF/VHF Radios. At large facilities the communications switch must be able to access 100 UHF/VHF radios, at medium size facilities - 50 UHF/VHF radios, and at small facilities - 20 UHF/VHF radios. The system must be capable of allowing any radio to be accessible from multiple positions.

Parameter 11: Number of Telephone Lines. At large facilities the communication switch must be able to access 100 telephone lines, medium size facility - 50 telephone lines, and a small facility - 30 telephone lines. The system must be capable of allowing any trunk or land line to be accessible from multiple positions.

Parameter 12: Number of A/G Radios Per Position. In a large facility each position must have access to 30 A/G radios, medium size facility - 25 A/G radios, and in a small facility - 20 A/G radios.

Parameter 13: Number of Interfaces Per Position. In a large facility each position must support 50 interfaces, medium size facility - 50 interfaces, and in a small facility - 20 interfaces.

Parameter 14: Power Source. FAA Order 6950.2C, Electrical Power Policy, states that backup electrical power is required in NAS facilities to ensure continued service in the event of primary power outages. The system must be serviced from a conditioned and uninterruptible power source. As an integral part of the system, independent backup to sustain critical communication circuits must be provided. This capability will provide for emergency communications.

Parameter 15: Connect air-to ground (A/G) or ground-to-ground (G/G) Lines. The FAA requires the system to connect any chosen line to the controllers headset and microphone within 230 mseconds despite peak communications traffic load on the system.

Parameter 16: Electromagnetic Compatibility (EMC). The system must be electromagnetically compatible with other equipment located at the facility.

RCM PART III:

REQUIREMENTS CORRELATION MATRIX

PART III

(Rational & Needs/Requirements Changes)

AS OF DATE:

DIGITAL AIRPORT SURVEILLANCE RADAR (DASR)

Parameter 1: žCompatibilityÓ was changed to žInteroperability.Ó New parameter definition ensures proper DASR/Automation interface under all appropriate format conditions.

Parameter 1a: DoD Format was introduced to ensure proper DASR interface with fielded DoD automation systems during a transition period if the DASR is available prior to the FAA AAS automation system.

Parameter 1b: FAA Format was introduced to explicitly ensure proper interface with the FAA AAS automation system.

Parameter 2: The title žWeather RadarÓ was changed to žWeather ProcessingÓ in order to more explicitly state the need to detect precipitation intensity in terms of the six calibrated National Weather Service levels. Reference to displayed levels was eliminated since display is an automation function not a radar function. However, the number of žreportedÓ levels was retained. Weather update was introduced to identify the need for current weather information to support flying mission requirements.

Parameter 3a: A threshold of 20,000 feet AGL was established based on fielded system capabilities.

Parameter 3b: The objective was changed from ž0.5 to 55Ó nautical miles to ž0.5 to 60Ó nautical miles to document the DoDŪs preferred coverage volume.

Parameter 3c: Azimuth was added to completely define the required three dimensional radar coverage volume.

Parameter 4: Probability of Detection threshold was determined to be 80% at 55 nautical miles since that is the performance range of the ASR-9 which is the currently fielded radar supporting ATC mission requirements. The DoD objective, 90% probability of detection at 60 nautical miles, will enhance mission support.

Parameter 5: Subclutter Visibility was identified as a Key Parameter to ensure the required level of clutter rejection to support the ATC mission. A threshold of 42 dB was established.

The objective (changed from ≥48 dB to ≥55 dB) would provide a substantial increase in moving target detection while operating in ground clutter.

Parameter 6a: A threshold of 400 aircraft targets was established. The objective was changed from 700 to 900 based on anticipated change in future mission requirements.

Parameter 6b: Non-aircraft targets threshold of 300 was established. An objective to process up to 500 non-aircraft targets was established based on an expanded system capability.

Parameter 7: False target threshold of ≤10 was established.

Parameter 8: Threshold of ≤0.8 seconds was established. Objective was changed from ≤0.8 seconds to ≤0.2 seconds.

Parameter 9: Thresholds of ≤275 feet RMS range accuracy and ≤0.16 degrees RMS azimuth accuracy are established.

Parameter 10: Nominal update rate threshold of 4.8 seconds was established based on fielded primary radar capabilities.

Parameter 11: The operational availability threshold of ≥99.8% was established. This is the current fielded system capability and is adequate to support terminal ATC operations.

Parameter 12: Threshold of 85 knots was established, and objective was changed from 80 knots to 85 knots based on current fielded system capability.

Parameter 13: Reliability thresholds of ≥750 hours MTBF, and ≥3,400 hours MTBCF were established based on fielded system capability and are consistent with the required operational availability of ≥99.8%. Objective values of ≥1,500 hours MTBF and ≥10,000 hours MTBCF were established to reflect the capability of emerging technology.

Parameter 14a: žMTTRÓ was changed to žMRTÓ because MRT is the appropriate operational term, whereas MTTR is a contractual term. A threshold of ≤1.0 hour based on maintenance specifications of fielded systems was established.

Parameter 14c: žMaxTTRÓ was changed to žMaxRTÓ because this is now the appropriate operational term. A threshold of ≤3.0 hours based on maintenance specifications of fielded systems was established.

Parameter 14e: A threshold of ≤6.0 hours/month was established based on maintenance specifications of fielded systems. The objective was changed to ≤1.0 hour/month for the same reason.

Parameter 14f: Thresholds of ≥90% for automatic and ≥95% for manual were established.

Parameter 15: The title žPower SupplyÓ was changed to žPower SourceÓ and new parameters 15a (primary/backup), and 15b (prevent data loss) were defined to clarify actual power requirements for the facility and the system. The primary/backup power source threshold was established as žcommercial plus engine generator backupÓ to meet FAA requirements for facility power, and prevention of data loss was stipulated for the system. The objective was changed from žconditioned/uninterruptibleÓ to žcommercial plus engine generator backupÓ to meet FAA requirements for facility power, and prevention of data loss was stipulated for the system.

Parameter 16: New parameter žResolutionÓ was introduced to specify the capability of the radar to distinguish closely spaced targets as required in support of the ATC mission.

Parameter 16a: New parameter žRange ResolutionÓ was introduced to define the minimum discernible longitudinal or radial aircraft separation.

Parameter 16b: New parameter žAzimuth ResolutionÓ was introduced to define the minimum discernible lateral aircraft separation.

SECONDARY SURVEILLANCE RADAR (SSR)

Parameter 1: žCompatibilityÓ was changed to žInteroperabilityÓ to ensure proper SSR/Automation interfacing under all appropriate format conditions. Mode S was introduced as an objective.

Parameter 1a: DoD Format was introduced to ensure proper SSR interfacing with fielded DoD automation systems during a transition period.

Parameter 1b: FAA format was introduced to explicitly ensure proper interfacing with the FAA AAS automation system.

Parameter 2: žMode S CompatibilityÓ in ORD I was deleted as a parameter (but as noted above, it was included as an objective in Parameter 1) since Mode S was not included in the Milestone I baseline recommendation. The Mode S issue continues to be reviewed. Due to this deletion, ORD I Parameter 3 was renumbered as ORD II Parameter 2.

Parameter 2a: Altitude coverage of 60,000 feet AGL was established as a threshold.

Parameter 2b: Azimuth coverage of 360 degrees was established as a threshold.

Parameter 2c: Range threshold of 120 nautical miles was established. The objective value was changed 200 nautical miles to reflect fielded system capability.

Parameter 3: ORD I Parameter 4 was renumbered. Update rate threshold of 4.8 seconds (nominal) was established. Objective of ževery 4 secondsÓ was changed to read ževery 4 or 2 seconds at selected locationsÓ to accommodate the requirements of a broader range of DoD ATC users.

Parameter 4: ORD I Parameter 5 was renumbered. Target capacity threshold of 400 was established. Objective was increased from 700 to 900 based on user needs.

Parameter 5: ORD I Parameter 6 was renumbered. Threshold range accuracy of ≤190 feet and azimuth accuracy of ≤0.26 degrees were established.

Parameter 6: ORD I Parameter 7 was renumbered. žBlip Scan RatioÓ was renamed žProbability of DetectionÓ as the measure of link performance more operationally appropriate to ATC mission support. Threshold of ≥97.0% was established.

Parameter 7: ORD I Parameter 8 was renumbered. Threshold of ≥3,400 hours was established.

Parameter 8: ORD I Parameter 9 was renumbered. Threshold of ≥98.0% was established.

Parameter 9: ORD I Parameter 10 was renumbered. Maintainability objective values were adopted as threshold values.

Parameter 10: ORD I Parameter 11 was renumbered and the title žPower SupplyÓ was changed to Power Source.Ó New parameters 10a (primary/backup), and 10b (prevent data loss) were defined to clarify actual power requirements for the facility and the system. The primary/backup power source threshold was established as žcommercial plus engine generator backupÓ to meet FAA requirements for facility power, and prevention of data loss was stipulated for the system. The objective was changed from žconditioned / uninterruptibleÓ to žcommercial plus engine generator backupÓ to meet FAA requirements for facility power, and prevention of data loss was stipulated for the system.

Parameter 11: New parameter žResolutionÓ was introduced to specify the capability of the SSR to distinguish closely spaced targets as required in support of the ATC mission.

Parameter 11a: New parameter žRange ResolutionÓ was introduced to define the minimum discernible aircraft separation in range.

Parameter 11b: New parameter žAzimuth ResolutionÓ was introduced to define the minimum discernible aircraft separation in azimuth angle.

Parameter 12: New parameter žFalse TargetsÓ was introduced to define the average number of false targets allowed per radar scan.

Parameter 13: New parameter žAntenna Wind Bearing CapabilityÓ was introduced for the secondary radar antenna to coincide with the primary radar antenna capabilities.

DoD ADVANCED AUTOMATION SYSTEM (DAAS)

Parameter 1: The title žCompatibility Data ProcessingÓ was changed to žInter/Intrafacility Data TransferÓ to more accurately reflect the ATC functionality required for FAA/DoD interoperability. FAA NAS has over 100 interfaces of which ATC is a subset and this parameter was changed to identify the critical ATC interfaces for interoperability.

Parameter 1a: Automatic transfer of position track data was established to identify specific ATC processing required to satisfy the FAA Interface Control Document (ICD) for inter-facility data transfer of track data, both format and processing time (NAS-MD-601/610). This function was identified as a Key Parameter.

Parameter 1b: Electronic inter-facility transfer of flight plans was established to identify specific ATC processing required to satisfy the FAA ICD for inter facility data transfer of flight plan data, both format and processing time (NAS-MD-601/610). This function was identified as a Key Parameter.

Parameter 1c: Interface with existing/future FAA/DoD ATC systems was established to identify interoperability during the established life-cycle of the DAAS.

Parameter 2: Objective value was established for enhanced track processing to support ATC safety functions such as minimum safe altitude warning (MSAW) and conflict alert/Mode C intruder (CA/MCI).

Parameter 3: ORD I Parameter 3 žRecordÓ is now covered in Parameter 4c. ORD I Parameter 4 žWeather DisplayÓ was renamed žDisplay Weather Levels (simultaneously with aircraft)Ó to clarify the automation requirement. A threshold of simultaneous display of six reported levels was defined. The objective was redefined to the simultaneous display of six reported levels.

Parameter 4: ORD I Parameter 5 was renumbered and the title žWorkstationsÓ was changed to žFacility ConfigurationÓ to further clarify parameter description. The definition of the parameter was changed/expanded as described below; new thresholds and objectives capturing the essence of the ORD I objective were defined.

Parameter 4a: Facility configuration information was established to identify critical information required for safe ATC operations. The automation system must accept supervisor requests for facility information within 0.5 seconds of message entry.

Parameter 4b: Reassignment of airspace to controller positions was established to support facility configurations due to shift workloads, equipment failures and special mission support. Mean response time for an airspace reassignment message must be 5.0 seconds or less.

Parameter 4c: Support synchronized recording of voice and data was established as a threshold.

Parameter 4d: Keyboard input response required to support ATC operations was introduced. An objective of ≤50 milliseconds and threshold of ≤250 milliseconds were established.

Parameter 5: New parameter žController Position VisibilityÓ was added. Threshold and objectives of žAll operational environmentsÓ were established to assure flexibility and usability of future ATC equipment and any facility operational lighting environment.

Parameter 6: žMCFÓ, žLCFÓ, and žMCTÓ were redefined as žLargeÓ, žMediumÓ, and žSmallÓ facilities respectively because facility types do not necessarily determine system size. ORD I objective values were adopted as the threshold.

Parameter 7: ORD I title žWorkstation Cov. (nm)Ó was renamed žRadar/Beacon Surveillance Data Presentation (nm)Ó to accurately reflect the intent of the DAAS characteristic for two modes of operation -- mosaic and single sensor. žMCFÓ, žLCFÓ, and žMCTÓ were redefined as žLargeÓ, žMediumÓ, and žSmallÓ facilities respectively because facility type does not necessarily determine system size. Threshold and objective values based on the ORD I objective were established.

Parameter 8: žTrackingÓ was renamed žStand-Alone Automatic TrackingÓ to clarify the definition of the parameter. Threshold and objective values based on the ORD I objective were established.

Parameter 9: žTarget TrackingÓ was renamed žAircraft TrackedÓ to clarify the intent of the parameter. Parameter definitions of žMCFÓ, žLCFÓ, and žMCTÓ were redefined as žLargeÓ, žMediumÓ, and žSmallÓ facilities because facility type does not necessarily determine system size. Thresholds and objectives were established to reflect the range of user acceptable values. Identified as a Key Parameter for the žMediumÓ size facility.

Parameter 10: ORD I Parameters 10 and 11 were combined in new parameter žRadar CapacityÓ for improved clarity. žMCFÓ, žLCFÓ, and žMCTÓ were redefined as žLargeÓ, žMediumÓ, and žSmall.Ó New threshold and objective values were established.

Parameter 11: ORD I Parameter 13 was renumbered. Threshold of ≥99.8% was established.

Parameter 12: A MTBCF threshold of ≥5,000 hours was established. A new objective of ≥12,000 hours was established. (Note: ORD I Parameter 12 žFlight plansÓ is now incorporated in Parameter 21c.)

Parameter 13: ORD I Parameter 15 was renumbered. žMTTRÓ and žMaxTTRÓ were changed to žMRTÓ and žMaxRTÓ respectively to redefine requirements in operational vice contractual terms. Thresholds were established.

Parameter 14: ORD I Parameter 16 žCold StartÓ was renumbered and renamed as žFailure RecoveryÓ to more accurately reflect the desired capability. New threshold and objective were established.

Parameter 15: ORD I Parameter 17 was renumbered and the title was slightly modified. žMCFÓ and žLCFÓ were redefined as žLargeÓ and žMediumÓ size facilities respectively. ORD I objectives adopted as thresholds. Medium objective increased from four to six.

Parameter 16: ORD I Parameter 18 was renumbered. ORD I objective adopted as threshold.

Parameter 17: ORD I Parameter 19 was renumbered. Wording of the parameter value was changed from žwkst/facÓ to žLocal/RemoteÓ for clarity with respect to the parameter description in the text and RCM Part II. Threshold and objective were established as žLocal/Remote.Ó

Parameter 18: ORD I Parameter 20 was renumbered. ORD I objective of žNAS management systemÓ was adopted as the threshold.

Parameter 19: ORD I Parameter 21 was renumbered. ORD I objective of žConditioned/uninterruptibleÓ was adopted as the threshold.

Parameter 20: ORD I Parameter 22 was renumbered. Objective of žSupport computer trainingÓ was established as the threshold.

Parameter 21: This new parameter was established to stress the importance that the system must be able to process flight progress information essential to aircraft sequencing and separation, and to facilitate intrafacility transfer of aircraft.

Parameter 21a: Local or remote flight progress information and amendment data was identified as a requirement. This information must be accepted by the ATC system.

Parameter 21b: Electronic transfer of flight data information between controller positions and remoted facilities was identified as a requirement to reduce controller workloads and manual flight plan management.

Parameter 21c: Incorporates ORD I Parameter 3. The number of flight plans processed (active and stored) depends upon the size and mission of facility. Threshold values of 150, 150, 75 were established for Large, Medium, and Small facilities respectively.

Parameter 22: New parameter žDisplay Weather and Airport Environmental DataÓ was introduced to identify essential weather and airport environment information in determining the terminal operational environment (i.e., traffic patterns, approach paths, departure paths, etc.) and runway configuration. The system is required to support data selection.

Parameter 23: New parameter žStand-Alone Conflict Alert ProcessingÓ is a required safety feature to predict if two tracked targets may get unacceptably close to each other at some future time. System must have the capability to inhibit conflict alert within a facility airspace (i.e., approach and departure ends of runway) to avoid false alarms.

Parameter 24: New parameter žStand-Alone Minimum Safe Altitude Warning (MSAW)Ó is a required safety feature to predict if tracked targets may descend unacceptably close to the ground or an area of rising terrain. System must have the capability to inhibit MSAW within a facility airspace (i.e., approach and departure ends of runway) to avoid false alarms.

Parameter 25: New parameter žDisplay AccuracyÓ was introduced to identify the level of display accuracy required to support ATC operations. An objective of ≤0.005 nautical miles and a threshold of ≤0.125 nautical miles or ≤0.4% of range were established.

VOICE SWITCHING SYSTEM

Parameter 1: žCapability/InteroperabilityÓ was renamed žInteroperabilityÓ to eliminate redundancy with Parameter 4, and identified as a Key Parameter. Parameter 1 now addresses interface with the FAA systems. The threshold requires interface capability with existing FAA voice systems.

Parameter 2: For clarification the threshold was changed to žAll operational environmentsÓ because different facilities may operate under light intensities.

Parameter 3: Parameter name changed for improved clarity.

Parameter 4: System interface capability parameter was modified to eliminate redundancy with Parameter 1. Parameter 4 now addresses interface with DoD systems.

Parameter 5: žReconfiguration TimeÓ was changed to žReassign Frequencies and Voice Channels to Controller PositionsÓ to more clearly state the required capability. The objective improved from 30 seconds to ≤15 seconds due to user identified requirement for more rapid response to system changes. Threshold reflects limits of available Non Developmental Item (NDI) technology. The threshold established for this parameter is ≤60 seconds.

Parameter 6: The operational availability threshold has been established as ≥99.8%.

Parameter 7: The reliability threshold has been established at ≥6,000 hours.

Parameter 8: The maintainability values were established as threshold values. Mean time to repair (MTTR) was changed to Mean Repair Time (MRT) to clarify operational term. Maximum to Repair (MaxTTR) was changed to Maximum Repair Time (MaxRT) to clarify operational term.

Parameter 8g: Restart time increased to within 60 seconds reflecting limits of current digital NDI technology.

Parameter 8f: BIT/FI thresholds of ≥90% and ≥95% for automatic and manual, respectively, were established based on fielded equipment specifications.

Parameter 9: Changed subsystem characteristics from facility type to system size because facility type does not necessarily determine system size. žMCFÓ, žLCFÓ, žMCTÓ will now be referred to as žLargeÓ, žMediumÓ, žSmallÓ systems. The new thresholds and objectives for the number of communications positions required for Small, Medium, and Large systems are: 9, 36, and 75 respectively.

Parameter 10: Established thresholds and objectives of 20, 50, 100 UHF/VHF radios required for Small, Medium, and Large systems respectively.

Parameter 11: Established thresholds and objectives of 30, 50, 100 telephone lines required for Small, Medium, and Large systems respectively.

Parameter 12: Established thresholds and objectives of 20, 25, 30, A/G radios required per position in Small, Medium, and Large systems respectively.

Parameter 13: Established thresholds and objectives of 20, 50, 50, interfaces per position in Small, Medium, and Large systems respectively.

Parameter 14: ORD I Parameter 14 žTraining SupportÓ has been determined not part of the voice system and, therefore, was deleted. ORD I Parameter 15 žPower SourceÓ was renumbered. The power supply objective žConditioned/ uninterruptibleÓ has been upgraded to a threshold value. A new parameter žSustain Critical CircuitsÓ has been established to provide for independent backup for critical communications circuits.

Parameter 15: New parameter žConnect A/G or G/G LinesÓ to any controller position is subsystem characteristic added to provide a time limit on this fundamental requirement. The system must be able to establish duplex connection, two-way voice, within 230 milliseconds (1/4 second) (threshold and objective).

Parameter 16: New parameter žElectromagnetic CompatibilityÓ was added, and threshold and objective values of žYesÓ indicating that the system must incorporate compatibility provisions were established.

ATTACHMENT 2

REFERENCES

1. USAF PMD 404L/2062 (11)/PE 35137F, Air Traffic Control and Landing Systems, dtd 19 Mar 91.

2. FAA Capital Investment Plan (CIP), Dec 90.

3. FAA/DOD Memorandum of Agreement on the Future of Radar Approach Controls in the NAS, 14 Dec 88.

4. DOD Air Traffic Control and Landing System Interoperability with the NAS (DAIN) Mission Need Statement, JROCM≠019≠89, 17 May  89.

5. HQ AFCC 04≠87, Statement of Operational Need (SON) NAS Compatible Air Traffic Control Facilities, 27 Oct 87.

6. Draft Joint Integrated Logistics Support Plan (JILSP), dtd 9 Nov 89.

7. The Federal Aviation Act of 1958.

8. Public Law 91≠190, 42 U.S.C. 4321 4347, 1 Jan 70, as amended by Public Laws 94≠52 and 94≠83, The National Environmental Policy Act of 1979.

9. 40 CFR Parts 1500≠1508, 29 Nov 79, CEQ Regulations for Implementing the Procedural Provisions of the National Environmental Policy Act.

10. DOD Directive 5000.2, 21 Feb 91.

11. AFR 80≠14, Test and Evaluation, 3 Nov 86.

12. FAA ORDER 6950.2C, "Electrical Power Policy implementation at National Airspace System Facilities", dtd 11 Nov 87.

ATTACHMENT 3

POINTS OF CONTACT

A. DOD Offices:

(1) DOD Policy Board on Federal Aviation Working Group

Washington, DC

Mr Frank Colson, Chairman

DSN 227≠6937

Lt Col P. Hamilton

DSN 225≠9274

(2) DOD NAS Program Requirements Office (NASPRO)

HQ FAA/ASD≠7

Washington, DC 20591

Col Edward Chelkowski (USAF)

Comm (202) 287≠8548

Lt Col John Marksteiner (USA)

Comm (703) 614≠2257

CAPT Jesse Salter (USN)

Comm (202) 267≠9431

(3) Office, Secretary of Defense

OASD/C3I

Washington, DC

Lt Col Jules McNeff

Comm (202) 695≠6123

B. Air Force:

(1) HQ USAF, Washington, DC

Program Element Monitor

Captain William Tarvin, SAF/AQPC

DSN 224≠4590

Program Monitor

Maj E. Wright, XOOA

DSN 224≠2129

(2) Air Force Flight Standards Agency, Washington, DC

USAF NAS Requirements and Transition

Mr Michael Higgins

DSN 224-7678

Comm 703-614-7678

NAS Integrated Logistics Support, Scott AFB, IL

Mr R. Martin, HQ AFC4A/SYAF

DSN 576≠8551

(3) Electronic Systems Center (Air Force Materiel

Command) Hanscom AFB, MA 01731

Program Director

Col J. Clay, HQ ESC/TG

DSN 478≠4953

C. Army:

(1) Commander, U.S. Army Aviation Center

ATTN: ATZQ≠ATC-SR

Ft Rucker, AL 36362-5265

NAS Focal Point

Mr Dave Fonda

Director, U.S. Army Air Traffic Control Activity

DSN 558≠5670/2508

Comm (205) 255-5670/2508

(2) Director, U.S. Army Aeronautical Services Agency

ATTN: MOAS-ZA

Bldg 2

Cameron Station, VA

Col Kenneth Hufford

DSN 284≠7750

(3) Headquarters, Department of the Army

ATTN: DAMO≠FDV (Mr. Yates)

Washington, DC

Mr. Roger W. Yates

DSN 224≠2257

D. Navy:

(1) Airspace, Airfields, Air Traffic Control and Range

Branch

CNO N885F2

Washington, DC

NAS Focal Point

CAPT (sel) J.R. Calhoun

DSN 224-2710

Comm (202) 614≠2710

(2) COMNAVAIRSYSCOM

PMA≠213

Washington, DC

NAS Focal Point

LCDR B. A. Fernald

Mr. Mike Kreul

DSN 222≠3701

Comm (703) 692-3700

(3) NAVELEXCEN Charleston (Code 313)

4600 Marriott Drive

North Charleston, SC 29406

Mr Philip Braswell

DSN 563-2030 x4813

Comm (803) 745-4813

E. Major Range Test Facility Bases

Joint Commanders Group (T & E) NAS Requirements

DOD NAS Program Requirements Office (NASPRO)

HQ FAA/ASD-7

Washington, DC 20591

Maj J. Hollenberg

Comm (202) 287-8551

ATTACHMENT 4

GLOSSARY OF TERMS

PART I: ACRONYMS

AAS Advanced Automation System

ACCC Area Control Computer Complex

ACF Area Control Facility

AERA Automated Enroute Air Traffic Control

AFC4A Air Force Command, Control, Communications and Computers Agency

AGL Above Ground Level

ALDT Administrative and Logistics Delay Time

ARTS Automated Radar Terminal System

ASR Airport Surveillance Radar

ATCALS Air Traffic Control and Landing Systems

ATC Air Traffic Control

ATCRBS Air Traffic Control Radar Beacon System

ATIS Automatic Terminal Information Service

AWDS Automated Weather Distribution System

BIT Built In Test

BRANDS Bright Radar Alphanumeric Display System

BRITE Bright Radar Indicator Tower Equipment

CC Common Console

CCDS Consolidated Cab Display System

CIP Capital Investment Plan

CONUS Continental United States

COTS Commercial Off the Shelf

CRF Consolidated Radar Facility

DAIN DOD ATCALS Interoperability with the NAS

DASR Digital Airport Surveillance Radar

DAAS DOD Advanced Automation System

DBRITE Digital Bright Radar Indicator Tower Equipment

DOD Department of Defense

ECM Electronic Counter Measures

ECCM Electronic Counter Counter Measures

ESD Electronic Systems Division

FAA Federal Aviation Administration

FACT Facilities Coordination Team

FDIO Flight Data Input≠Output

FI Fault Isolation

FOC Full Operating Capability

FOUO For Official Use Only

GPS Global Positioning System

ICAO International Civil Aviation Organization

IFF Identification Friend or Foe

IFR Instrument Flight Rules

IOC Initial Operating Capability

ISSS Initial Sector Suite System

IVCSS Integrated Voice Communications Switching System

JILSP Joint Integrated Logistics Support Plan

JPCO Joint Procurement Coordinating Office

JSORD Joint System Operational Requirement Document

LCF Local Control Facility

LRU Line Replaceable Unit

LOS Line of Sight

LRR Long Range Radar

LSA Logistics Support Agreement

LSAR LSA Records

MAMS Military Airspace Management System

MARSA Military Assumes Responsibility for Separation of

Aircraft

MCF Metroplex Control Facility

MCT Military Control Tower

MILCON Military Construction Program

MLS Microwave Landing System

MODE S Discrete Addressable Secondary Radar System

MTRACON Military Terminal Radar Approach Control

MSAW Minimum Safe Altitude Warning

NAS National Airspace System

NASDAP NAS Defense Acquisition Panel

NASPRO NAS Program Requirements Office

NEXRAD Next Generation Weather Radar

NOTAM Notice to Airmen

O&M Operations and Maintenance

ORD Operational Readiness Date

ORD I Milestone I Operational Requirements Document

OT&E Operational Test and Evaluation

PIDP Programmable Indicator Data Processor

PMD Program Management Directive

PSR Primary Surveillance Radar

RAPCON Air Force Radar Approach Control

RCE Radio Control Equipment

RDT&E Research Development Test and Evaluation

SERD Support Equipment Requirement Data

SON Statement of Need

SRR Short Range Radar

SUA Special Use Airspace

TAAS Terminal Advanced Automation System

TACS Theater Air Control System

TCCC Tower Control Computer Complex

TCS Tower Communication System

TRACON Terminal Radar Approach Control

T/RT TCCC/Remote TRACON

TSAS Tower Standard Automation Suite

UHF Ultra≠High Frequency

VFR Visual Flight Rules

VHF Very-High Frequency

VCSS Voice Communications Switching System

VSCS Voice Switching and Control System

THE FOLLOWING DEFINITIONS APPLY TO THRESHOLDS AND OBJECTIVES:

MUST A binding statement. Reflects a critical system requirement (i.e., Threshold).

SHOULD Used to express what is probable or expected (i.e., Objective).

WILL A statement used to express future requirements (i.e., Objective).

GLOSSARY OF TERMS

PART II: MAINTENANCE TERMS

THIS SECTION IS INTENDED TO PROVIDE THE USERS OF THIS DOCUMENT WITH A WORKING KNOWLEDGE OF APPLICABLE MAINTENANCE TERMS USED HEREIN:

ALIGNMENT Performing the adjustments that are necessary to return an item to specified operation.

AVAILABILITY A measure of the degree to which an item is in an operable and commitable state at the start of a mission when the mission is called for at an unknown (random) time.

BIT Built≠In≠Test

BITE Built In Test Equipment

CALIBRATION A comparison of a measuring device with a known standard.

CHECKOUT TIME The time required to perform test or observations of an item to determine its condition or status.

CRITICAL FAILURE A failure, either software or hardware, or combination of failures that prevents an item from performing a specified mission.

DISASSEMBLY TIME The time required to disassemble equipment to the extent necessary to gain access to the item that is to be replaced.

INTERCHANGE TIME The time required to remove the defective item and install the replacement.

ISOLATION TIME The time required to determine the isolation of the fault to the extent necessary to effect repair.

LOCALIZATION TIME The time required to determine the isolation of the fault to the extent necessary to effect repair.

LINE REPLACEMENT An item that is normally removed and replaced

UNIT (LRU) placed as a single unit to correct a deficiency or malfunction on a weapon or support system and item of equipment. Such items have a distinctive stock number for which spares are locally authorized to support the removal and replacement action. These items are repair cycle assets subject to DIFM controls (T.O. 00-20-3) and may be disassembled into separate components during shop processing.

MAINTENANCE All actions necessary for retaining an item in or restoring it to specified condition.

CORRECTIVE All actions performed as a result of failure.

MAINTENANCE Corrective Maintenance can include any or all of the following steps: Localization, Isolation, Disassembly, Interchange, Reassembly, Alignment and Checkout.

PREVENTIVE/ Maintenance performed at a prescribed point

SCHEDULED in the item's life in an attempt to retain

MAINTENANCE an item in a specified condition by providing systematic inspection, detection and prevention of incipient failures.

ADMINISTRATIVE Administrative delay time (ADT) refers to

DELAY TIME that portion of downtime during which maintenance is delayed for reasons of an administrative nature; personnel assignment priority, labor strike, organizational constraint, and so on. ADT does not include active maintenance time, but often constitutes a significant element of total maintenance downtime.

LOGISTIC DELAY Logistics delay time (LDT) refers to that

TIME maintenance downtime that is expended as a result of waiting for a spare part to become available, waiting for the availability of an item of test equipment in order to perform maintenance, waiting for transportation, waiting to use a facility required for maintenance, and so on. LDT does not include active maintenance time, but does constitute a major element of total maintenance downtime.

MEAN TIME BETWEEN A basic measure of reliability for repairable

FAILURE items: The mean number of life units (hours)

during which all parts of the item perform within their specified limits, during a particular measurement interval under stated conditions.

MEAN TIME BETWEEN A measure of the reliability taking into

MAINTENANCE account maintenance policy. The total number of life units (hours) expended in a given time.

MAINTENANCE MMH/OH = TOTAL MAINTENANCE MAN≠HOURS*

MAN≠HOURS PER GENERAL TOTAL OPERATING HOURS

OPERATION HOUR

(MMH/OH) * Excluding support work

MEAN TIME TO The average time to restore the system to

RESTORE SYSTEM operational status; derived by dividing the

(MTTRS) total corrective maintenance time by the total number of failures during a stated period of time. Includes administrative and logistic delay times.

MEAN MAN≠HOURS The average number of man≠hours to repair an

TO REPAIR (MMR) item; derived by dividing the total number of base≠level corrective man≠hours by the total on≠equipment corrective maintenance events for a given period of time, or:

MMR = TOTAL MAN≠HOURS FOR CORRECTIVE MAINTENANCE

NUMBER OF MAINTENANCE EVENTS

MEAN TIME BETWEEN The average time between critical failures;

CRITICAL FAILURE is derived by dividing the total equipment

(MTBCF) operating hours by the number of critical failures.

MTBCF = TOTAL EQUIPMENT OPERATING HOURS

NUMBER OF CRITICAL FAILURES

MEAN TIME BETWEEN The average time between maintenance actions

MAINTENANCE derived by dividing the total number of

ACTIONS (MTBMA) equipment operating hours by the number of maintenance events.

MTBMA = TOTAL EQUIPMENT OPERATING HOURS

NUMBER OF MAINTENANCE EVENTS

* Includes maintenance due to malfunctions, no defects found, and events due to preventive maintenance inspections (PMIs).

MEAN REPAIR TIME The average time to repair an item; derived

(MRT) by dividing the total time required to localize, isolate, disassemble, interchange, reassemble, align and checkout by the total number of repair events. MRT does not include any logistics or administrative delay times.

MAXIMUM TIME That value of maintenance downtime below which TO REPAIR a specified percent of all maintenance actions

(MaxTTR) can be expected to be completed. MaxTTR is related primarily to the log-normal distribution, and the 95th percentile point is the specified value for the purpose of this ORD.

OPERATIONAL (Ao) The probability that a system or equipment, AVAILABILITY when used under stated conditions in an actual operational environment, will operate satisfactorily when called upon.

Ao = MTBM (mean time between maintenance) MTBM + MDT (mean downtime)

MTBM = Mean time between any maintenance action that would take the system away from the operator (both preventive and corrective).

MDT = Total down time divided by the total number of maintenance events.

REMOTE MAINTENANCE A monitoring system that is not collocated

MONITORING SYSTEM with the end item equipment and is used to determine status, provide notification of equipment malfunction, determine resources necessary for repair of system, and in some cases make adjustment to equipment to bring equipment back into specification.

REASSEMBLY TIME The time required to close and reassemble the equipment after replacement has been made.

SETUP TIME The time to obtain, set up, interconnect, and warm up test equipment and/or tools.

TOTAL EQUIPMENT The hours the equipment is operationally

OPERATING HOURS available to perform its assigned mission;

(TEOH) maximum of 8766 hours/year.