II - OVERVIEW: TYPES OF AIRCRAFT



The Missile Technology Control Regime establishes a performance of a 300 kilometer range with a 500 kilogram payload as a threshold of concern for proliferation. These standards, which are readily applicable to combat aircraft,(1) encompass virtually the entire range of military combat aircraft, down to some the smallest trainers.

Combat aircraft elude ready classification. Important categories include the size and warload capacity of the aircraft, which can range across several orders of magnitude, as well as the vintage of aircraft, since more recent variant typically possess greater resistance to hostile action. In contract to missiles, placing combat aircraft into a precise category is a rather difficult task. Ballistic missiles are generally characterized by unique and fixed range and payload characteristics. But combat aircraft can trade between fuel carried for range and munitions carried for air-to-air and air-to-ground combat, with the maximum or ferry range of an aircraft typically being at least twice as great and up to ten times as great as the normal combat range, and maximum payloads up to four times greater than normal combat payloads. In addition, the flight profile of the aircraft can have a major impact on range, with low altitude missions easily cutting combat radius in half.

Combat aircraft are generally divided according to its primary assigned mission:

* Attack - designed or outfitted for air-to-ground attack;

* Dual-Role - designed or outfitted for both air-to-ground and

air-to-air combat;

* Fighter - designed or outfitted for air-to-air attack;

* Other - including trainers, reconnaissance, tankers, and

Airborne Early Warning.

Although older classes of aircraft are obviously not the equal of the latest products of the designers art, it would be a mistake to imagine that they are without significant military potential. Upgrades, including addition of state-of-the-art avionics, guided weapons, and more powerful modern engines, can significantly enhance the combat capabilities of older aircraft.(2) Some observers contend that even the venerable A-4 Skyhawk, with the addition of certain air-defense countermeasures, "remains as effective today as it was a quarter of a century ago."(3) Indeed such upgrades are the rule, rather than the exception, for the air forces of all countries.(4) Grumman signed a $245 million contract with China to substantially re-engineer the F-8 interceptor to the F-8 II standard, and several other Chinese aircraft incorporate Western systems, including the H-7 and Q-5 attack aircraft. Singapore and Israel do a brisk trade in modifying the F-5s, as well as the A-4s and F-4s (respectively) of a number of other states. Both France and Israel offer upgrades to various versions of Mirage aircraft.

While stealthy aircraft such as the A-12, F-117A and F-23, which have been designed from the outset to reduce their detectability, will undoubtedly retain an advantage over their more conventional brethren, upgrades are available to reduce this margin. Modifications to the Tornado include addition of radar absorbing materials and improved electronic countermeasures.(5) Upgrades to the F-14 could also significantly reduce its radar signature.(6) And stealth modifications have begun on some F-16s.(7)



STRATEGIC BOMBERS

Strategic bombers are the high end of combat aircraft, capable of delivering tens of tons of ordnance over intercontinental ranges. Older versions equipped with long-range cruise missiles include the Russian Bear and American B-52, while newer penetrating bombers armed with short range air-launched ballistic missiles and gravity weapons include the Russian Backfire and Blackjack, and the American B-1B and B-2. Unit costs of several hundred million dollars place such aircraft beyond the reach of most countries, and their intercontinental ranges place them beyond the interest of most operators. Thus these aircraft are essentially restricted to the United States and Russia, although the Soviet Union exported a handful of maritime patrol versions of the Bear to India.

ADVANCED STEALTH AIRCRAFT

These aircraft are currently being developed and produced by the United States. These extremely expensive aircraft a greatly reduced vulnerability to air defenses at the price of unit costs of $50 million to over $100 million, several times as high as those of more conventional aircraft. The first American stealth aircraft to enter service was the F-117A, which saw service in Panama in Saudi Arabia. A more capable stealth attack aircraft is the US Navy's A-12 Avenger II Advanced Tactical Aircraft, which will offer significant performance improvements over the current A-6.(8) The YF-22 and YF-23 of the Advanced Tactical Fighter (ATF) program combine low-observable stealth designs with advanced engines and aerodynamics for sustained supersonic cruise.(9) There is little expectation that these aircraft will be available for export any time soon.(10)

MODERN HEAVY ATTACK AIRCRAFT

Modern heavy attack aircraft include both theater range strategic bombers, as well as the largest and most capable tactical aircraft. American examples include the F-111 and F/B-111, the F-15E Strike Eagle, as well as the Navy's carrier-based A-6. European members of this class include the Tornado and Mirage IV, as well as the Russian Tu-22 Blinder and Su-24 Fencer. These aircraft, which can cost from $30 to over $500 million, generally carry 5 to 10 tons of ordnance to a combat radius of over 1,500 kilometers at supersonic speeds. Fewer than 100 of these aircraft are in service in Third World countries, including Tornado's in Saudi Arabia, and Tu-24 Blinders and Su-24 Fencers in Libya and Iraq.

MODERN MEDIUM COMBAT AIRCRAFT

These models, which can cost from $15 to over $50 million, generally carry 2 to 5 tons of ordnance to a combat radius of about 1,000 kilometers at supersonic speeds. While most are designed primarily for air-to-air combat, many of these aircraft can carry bomb loads greater than those carried by the B-17 and B-24 bombers of the Second World War.(11) Leading examples include the F-14, F-15, F-16 and F/A-18, the Jaguar, and the Russian MiG-27 and Su-29. More than 500 of these aircraft are in service in the air forces of over a dozen Third World countries.

MODERN LIGHT COMBAT AIRCRAFT

Modern light aircraft, which can cost up to $15 million, generally carry 1 to 5 tons of ordnance to a combat radius of about 500 kilometers, usually at supersonic speeds. Leading examples include the F-5, Alpha Jet, Hawk, MiG-23 and MiG-29, the Su-20 and Su-22, and various versions of the Dassault Mirage. Over 3000 of these aircraft are in service in the air forces of more than five dozen Third World countries.

OLDER BOMBERS

Older bombers generally carry anywhere from 2 to 10 tons of ordnance to a combat radius of from 500 to 3,000 kilometers at subsonic speeds. Primary examples include the Russian Il-28 and Tu-16, the Chinese H-5 and H-6 versions of these aircraft, as well as the B-57 Canberra of American and British origin. Although these aircraft typically lack the advanced electronic and other countermeasures needed to survive in a high-threat environment, they continue to pose a significant challenge to less sophisticated foes lacking in modern air-defenses, or deprived of air defenses by combat. Somewhat more than 100 of these aircraft are in service in seven Third World countries.

OLDER MEDIUM COMBAT AIRCRAFT

This type generally carries anywhere from 1 to 5 tons of ordnance to a combat radius of from 500 to 1,000 kilometers at supersonic speeds. Leading examples include the A-4 Skyhawk and the Su-7 Fitter. Nearly 800 these aircraft serve in air forces of over a dozen Third World countries.

OLDER LIGHT COMBAT AIRCRAFT

Aircraft in this category generally carry anywhere from 1 to 2 tons of ordnance to a combat radius of from 300 to 700 kilometers at supersonic speeds. Primary examples include the Russian MiG-17, MiG-19, and MiG-21, as well as the Chinese J-5, J-6 and J-7 versions of these aircraft. The air forces of nearly five dozen Third World countries deploy in excess of 3000 of these aircraft.

TRAINERS/LIGHT ATTACK AIRCRAFT

Trainers/light attack aircraft are primarily designed and used for pilot training. They also generally carry anywhere from 1 to 2 tons of ordnance to a combat radius of from 300 to 700 kilometers at supersonic speeds. Leading examples include the Hunter and L-39, and 400 these aircraft are in service in a nearly a dozen Third World countries. The trainer/light attack aircraft market is predicted to grow as defense budgets become tighter.

CLOSE AIR SUPPORT AIRCRAFT

Similar to trainers/light attack, close air support aircraft carry anywhere from 1 to 2 tons of ordnance to a combat radius of from 300 to 700 kilometers. But these aircraft are usually propeller-driven, in contrast to the turbo-jet engines used on all of the other aircraft previously discussed. The archetype of this class is the American OV-10 Bronco, used extensively in Viet Nam. And while most of these aircraft remain concepts or test prototypes, the Argentine Pucara saw combat use in the Falklands conflict. In the United Kingdom the British Aerospace has evaluated prop and jet versions of the Small Agile Battlefield Aircraft (SABA)(12) which could carry up to 2 tons of ordnance.(13) A 1987 study of options to replace the A-10 by the Institute for Defense Analysis recommended a 5 ton unducted-fan aircraft carrying one ton warload.(14) This study eventually led to DARPA tests of the ARES (Agile Responsive Effective Support) aircraft, built by Burt Rutan's Scaled Composites.(15)

AERIAL TANKERS

Aerial tankers are central to increasing the range and capabilities of attack aircraft, and are found in the inventories of all modern air forces. Refueling aircraft can be roughly divided into two categories; dedicated tankers and contingency or "buddy" tankers.

One trend in dedicated tankers is toward converted wide body airliners, since they can usually dispense about 135,000kg of fuel with spare space for cargo or passengers. The latest generation dedicated tanker is the KC-10, based on the McDonnell Douglas DC-10, which can carry 156,820 kg of fuel and dispense 118,000 kg 1,000 nm from its base.(16) There are, however, several platforms available, and the recent Japanese search for tanker aircraft illustrates this wide range options. Alternatives considered include the KC-707 for about $14.5 million, KCE-3J (similar to the KC-135R at a cost of $48 million) or KC-10J tanker aircraft, for about $100 million.(17)

Contingency tankers are fighter or attack aircraft carrying the maximum extra fuel and a refueling pod. The technique is not a very efficient means of refueling because it diminishes the number of available attack aircraft and the ratio of "refuelees" to refueler is low. Contingency tankers are most commonly used deep in hostile airspace where the threat to dedicated tankers is too great. The use of contingency re-fueling may grow however, as new aerial tactics focus on low-level all weather missions.

Tankers disseminate their goods either through a telescopic boom or a hose and drogue system. The boom is positioned by an operator on board the tanker into a receptacle on top of the receiving aircraft. When using the hose and drogue system, the receiving aircraft maneuvers its probe into the brogue trailing the tanker. The boom was developed by the US Air Force during SAC's hey day. Its advantage over the hose and drogue system is its massive fuel transfer rate. The KC10A, for example can dispense 5680 liters per minute through its boom and only 2270 liters per minute from the hose and drogue system. The boom's limitations are that only one aircraft can be refueled at one time, there is no back-up if the boom fails, and it must be adapted to refuel the hose and drogue aircraft flown by the US Navy and most other air forces. The majority of air forces employ the hose and drogue system. During Operation Desert Storm the lack of flexibility in US Air Force refueling dispensers caused operational problems, since several aircraft were incompatible with the boom apparatus. Thus, the Air Force is adapting its tankers to facilitate the refueling of more than one aircraft at a time.(18)

Tanker Characteristics(19)





	Type			Fuel offload 	 # of refuel-	Max fuel flow
				(liters)	ing points	lit/min
				boom/drogue	boom/drogue


	KC135A			43,000		1/2		4540/1590

	707-320			72,000		0+1/2+3		4540

	Il-78			52,000		-/3		-

	KC130H			27,000		-/2		-

	KC.Mk1			120,000		-/4		-/2330

	KC10A			160,000		1/3		5680/2270

	KA-6D			10,000		-/1		-/1325

	Tornado IDS
	Buddy pod		7,000		-/1		-/1590		





AIRBORNE EARLY WARNING

Airborne early warning aircraft are a central element of competent modern air defenses. Compared to ground-based radars, AEW aircraft can more than double the range at which high altitude aircraft can be detected (from 450 Km to 900 Km for a target at 10 Km altitude), while the improvement for detection of low altitude targets is even more striking (from 60 Km to 450 Km for an aircraft traveling at an altitude of 200 meters).(20) These aircraft are flying control towers. The crew of the E-3 AWACS, for instance includes 13 dedicated specialists including a tactical director, fighter allocator, two weapons controllers, surveillance controller, link manager, three surveillance operators, communications operator, radar technician, communications technician and computer display technician.(21) The Sentry's 9.14 meter in diameter rotodome acts either as a pulse and/or doppler radar for detection of aircraft targets. Recent upgrades have doubled the aircraft's performance against small targets such as cruise missiles and UAVs.(22)

The E-2c Hawkeye is the US Navy's AEW platform. To be suitable for aircraft carrier operations, the Hawkeye is much smaller than the AWACS. Its wing span is about half that of the E-3, and it is 127,264 kg lighter. The E-2c is powered by two turboprop engines as opposed to the AWACs four jet engines. The rotodome is 7.32 meters in diameter.(23) The E-2c also costs about 25 percent of the E-3. One important operational difference between the two aircraft is that the E-2 features a passive detection system that allows it to detect and locate up to 300 emissions from enemy radar transmitters, such as SAM sites, and air defense radars simultaneously. It also enables the E-2 crew to know when it has been painted by hostile radar, allowing for more responsive defensive action.(24)

Initially developed by the United States during the Second World War, today these aircraft are operated by more than a dozen countries. Manufacturing AEW aircraft is extremely challenging. Britain, for example, found it too challenging, and canceled its Nimrod AEW program in favor of purchasing US systems.

Israel, however, is in the process of manufacturing its own AEW aircraft indegenously. If successful, the Phalcon could represent a significant advance in early warning technology. Instead of employing a rotodome, the Israelis intend to conform six phased array antennas to the 707's airframe. This more aerodynamic shape would result in fuel savings and increase flight time. The Phalcon will also carry a host of non-radar sensors.(25) In an effort to stave off this foreign competition, Grumman and Lockheed announced in June 1991 that they would collaborate on marketing Grumman's E-2c radar on Lockheed's C-130 and P-3 aircraft. This would open a very large market of existing C-130s and P-3s to AEW modification.(26)



JSTARS

What AEW aircraft do for aircraft's aerial operations, JSTARS (Joint Surveillance and Target Attack Radar System) will do for aircraft ground attack operations. Based on a Boeing 707-323C, JSTARS employs a synthetic-aperture/Doppler radar to detect stationary and slowly moving ground targets up to 175 km behind the FLOT (front line of troops). Cruising for eight hours, JSTARS is capable of covering one million square km of area and can instantaneously transmit to ground stations or direct attacks through JTIDS (joint tactical information distribution system). Two JSTARS were deployed to the Persian Gulf during Desert Storm, where it was reportedly key to locating and tracking the movements of Scud launchers.(27) Considering the apparent ease with which the Iraqis were able to avoid detection and launch their mobile Scuds, it appears that further refinements to JSTARS will be required before its operational deployment date of 1997. In light of the high cost and questionable survivability of the aircraft, following the highly successful Israeli example and developing remotely piloted vehicles (RPVs) to do the same mission would be worth consideration.


References

1. "Panel Disputes U.S.-Soviet Arms Parity," Aviation Week & Space Technology, 28 June 1976, page 19.

2. Cook, Nick, "Ultimate Upgrades," Jane's Defense Weekly, 19 December 1987, pages 1429-1433.

3. Richardson, Doug, Modern Warplanes, (Crescent Books, New York, 1982), page 124.

4. Costello, Robert, "One Way to Extend the Pentagon Dollar," Christian Science Monitor, 30 July 1990, page 19.

5. "Tornados go 'Stealthy'," Flight International, 29 August 1990, page 7.

6. Morrocco, John, "Grumman Offers Tomcat 21 As Alternative to Navy ATF," Aviation Week & Space Technology, 7 November 1988, page 18-19.

7. Lok, Joris, "Stealth-modified F-16s in Service," Jane's Defense Weekly, 27 January 1990, page 133.

8. "A-12 Leading Contender for ATS," Aerospace Daily, 20 August 1990, page 281-283.

9. Scott, William, "YF-23A Previews Design Features of Future Fighters," Aviation Week & Space Technology, 2 July 1990, page 16-21.

10. "Israel Considers Fighter Replacement Options," Flight International, 1 August 1990, page 11.

11. Rhodes, Jeffrey, "Improving the Odds in Ground Attack," Air Force Magazine, November 1986, page 48-52.

12. Wood, Derek, "BAe Seeking Partners for Small Agile Battlefield Aircraft," Jane's Defense Weekly, 5 December 1987, page 1294-5.

13. "BAe Shows SABA Alternative," Flight International, 12 December 1987, page 8-9.

14. Morrocco, John, "Study Supports Call for Design of New Close Air Support Aircraft," Aviation Week & Space Technology, 28 September 1987, page 29-30.

15. Goold, Ian, "Rutan Prepares for First Flight of Agile Close-support Fighter," Flight International, 7 February 1990, page 18.

16. Wanstall, Brian, "Tankers boost combat credibility," Interavia, June 1989, p.561.

17. Ebata, Kensuke, "Japan Considers Contenders for Air-Refueling Tanker," Jane' Defense Weekly, 23 February 1985, pages 313-318.

18. Capaccio, Tony, "USAF Tankers To Be Adapted For Use By Navy and Marine Jets," Defense Week, 25 March 1991, p.3.

19. Chart derived from: Coniglio, Sergio, "Modern Air Refueling Systems," Military Technology, June 1991, p.93.

20. Hirst, Mike, Airborne Early Warning, (Osprey, London, 1983), page 40.

21. Jane's All the World's Aircraft, 1991-92, Jane's Information Group, 1991, Surrey, UK, p.364.

22. Jane's All the World's Aircraft, 1991-92, Jane's Information Group, 1991, Surrey, UK, p.364.

23. Jane's All the World's Aircraft, 1991-92, Jane's Information Group, 1991, Surrey, UK, p.406.

24. Mohr, Charles, "Radar Aircraft Built in US Play Role In Israel's Success," The New York Times, 12 June 1982, p.7.

25. Leopold, George, "Competition Rises for Early Warning Gear Makers," Defense News, November - December 1991.

26. Leopold, George, "Competition Rises for Early Warning Gear Makers," Defense News, November - December 1991.

27. Jane's All the World's Aircraft, 1991-92, Jane's Information Group, 1991, Surrey, UK, p.366.