sci.military.naval FAQ, Part D
Naval Aviation


Revised 30 March 2000
Version 1.53
Compiled and Maintained by: Andrew Toppan
SMN FAQ Main Page: http://www.hazegray.org/faq/

Contents of this section:
Section D.1: A/F-X
Section D.2: The JSF (ex JAST) program
Section D.3: Bell/Boeing V-22 Osprey
Section D.4: Yakovlev Yak-41/141 "Freestyle"
Section D.5: Is fighter X better than fighter Y?
Section D.6: Why do some aircraft have gold-tinted canopies?
Section D.7: Why do USAF aircraft have tailhooks?
Section D.8: Can X aircraft operate from a carrier?
Section D.9: Did a C-130 land on a carrier? How about a U-2?
Section D.10: The composition of an aircraft carrier's air wing
Section D.11: Why do the USAF/USN use incompatible refuelling systems?
Section D.12: Aircraft designations


Section D.1: A/F-X

The A/F-X (Attack/Fighter X) was a joint USAF/USN project to produce a heavy attack aircraft with a secondary fighter role; it would have replaced the F-111 and A-6 in the attack role, and (partially) the F-14 in the fighter role. It was a short-lived programme, originating in 1991 after the cancellation of the McDonnell Douglas/General Dynamics A-12, a highly advanced, highly stealthy aircraft intended to replace the A-6. A new programme, originally designated A-X, was initiated to provide a cheaper A-6 replacement. At the same time, the NATF (Naval Advanced Tactical Fighter) program, intended to produce an F-14 replacement, had recently been put on hold, and the USAF was starting to think seriously about an F-111 replacement. The three programmes were merged under the title A/F-X.

The leading contender was the Lockheed/Boeing AFX-653, essentially a navalised version of the USAF's F-22 Advanced Tactical Fighter (see below). This would have been a two-seat aircraft with Tomcat-like swing wings, but otherwise similar to the F-22. The A/F-X project was cancelled at the end of 1993; the US Navy intends to procure the F/A-18E/F series as partial replacements for its aircraft.

You can find an article on the subject, with plans of the AFX-653, in the 26-Jan-94 issue of Flight International.


Section D.2: The JSF (ex JAST) program

The US Joint Advanced Strike Technology programme, established in early 1994, was intended to be a technology development programme rather than an actual service aircraft. It involved all the improvements that would be expected for a next generation aircraft (advanced materials, stealth, reduced costs, better systems integration, and so forth), plus two particularly innovative concepts. The first is the idea of a modular aircraft design, so that individual aircraft could be built with different combinations of components for different services and missions (take-off capability, for example -- the same basic airframe could be built in conventional runway versions for the USAF, carrier-borne versions for the USN, and V/STOL versions for the USMC). The second is the possibility of providing a "virtual reality" environment for the pilot, which would integrate tactical information with the outside view.

JAST inherited much of the defunct A/F-X project, and has been partially combined with ARPA's X-32 project and is now called JSF, Joint Strike Fighter.

Twelve technology development contracts were awarded in May 1994, the largest going to Boeing. Two contractor teams out of Lockeed, McDonnell Douglas/Northrop and Boeing will each build two demonstrators, one to demonstrate the STOVL concept. Designations will be X-32A, B, C and X-35A, B and C for the USN (carrier), USAF (maybe RAF) (conventional) and USMC/RN (STOVL) versions.

The chosen JSF will replace the F-16 in USAF service, some F/A-18s and F-14s in USN service, and the Harrier in USMC/RN service.

(The X-32 started life as ARPA's ASTOVL (Advanced Short Take-Off/Vertical Landing) project, intended as a technology demonstrator to lead to a supersonic successor to the Harrier. This later became CALF (Common Advanced Lightweight Fighter), a more general demonstrator for a future lightweight fighter. The UK is also involved in the project, putting up about one third of the money. The design has been made small enough for service on Royal Navy carriers.)


Section D.3: Bell/Boeing V-22 Osprey

The tilt-rotor programme began with Bell's XV-15 technology demonstrator. A tilt-rotor multimission aircraft was commissioned under the title JVX (Joint VTOL X); the aircraft, developed jointly by Bell Helicopter Textron and Boeing Vertol, was later designated V-22 Osprey. The first prototype flew on 19 March 1989; development has been interrupted by the destruction of two of the prototypes in crashes.

Despite attempts by the US Secretary of Defence to have the programme halted in favour of conventional helicopters and transport aircraft, the Osprey has survived several rounds of budget cutting, thanks mainly to lobbying by the US Marine Corps. Current production plans consist of 552 MV-22B assault transports for the USMC (to replace the ancient CH-46) and 55 CV-22B special mission transports for the Special Operations Forces. The US Army's original requirement for 251 of the transport version has been deferred, but not irrevocably cancelled.

The program has proceeded at a slow pace, primarily because it has not become a budget priority outside the Marine Corps. The MV-22B is now in the early stages of series production, and the first prototype CV-22Bs are being built.


Section D.4: Yakovlev Yak-41/141 "Freestyle"

Design of the Yak-41 (or possibly Yak-141; see below) began in 1975; the first prototype flew in March 1987, followed by a second in April 1989. Tests were conducted on the aircraft carrier Admiral Gorshkov. In April 1991, one of the prototypes set several records for VTOL aircraft; it was displayed at the Paris Air Show shortly afterwards. One prototype was lost in a crash (attributed to pilot error) on the carrier in November 1991, after which development was suspended (due to lack of funds rather than any problems with the aircraft); the surviving aircraft was mothballed.

Yakovlev had announced that they intended to restart development of the Yak-41, apparently as a result of renewed interest from the Russian Ministry of Defence (a similar revival of the twin-turboprop Yak-44 AEW aircraft is also being considered). However, there has been no production of the aircraft to date, and there appears to be little chance of future production.

A more advanced version, the Yak-41M (Yak-141M?), has also been designed, with the emphasis now on Air Force rather than Navy service. This version has an extensively modified airframe, with a strong emphasis on stealth (there is a distinct resemblance to the F-22), a much more powerful engine, and more fuel and payload.

The "Freestyle" has been referred to as both Yak-41 and Yak-141; it appears that one designation refers to the standard fighter and one to the single prototype modified for record attempts, but there seems to be some uncertainty as to which is which.

This program is considered to be dead, due to a lack of potential customers. There are no remaining operational Russian carriers that would require VSTOL aircraft, and all foreign VSTOL carriers are using Harriers. It is very unlikely that any nation would choose to purchase a new, unproven, Soviet-design VSTOL aircraft when the Harrier is available.


Section D.5: Is fighter X better than fighter Y?

This is the kind of question that gets discussed all the time, but doesn't really have an answer.

First, best for what? Every fighter is designed with a particular set of requirements in mind. "Fighter" is a fairly general term that covers a multitude of missions. A Tornado F.3 or a MiG-31 is an excellent long-range interceptor, but you wouldn't want to send one of them up against an F-16 or an MiG-29 in a dogfight. But niether plane is inherently "better", rather, they are simply different planes for different roles.

Second, the aircraft itself isn't the only factor involved, or even the most important one. Put two aircraft of similar (or even somewhat different) capabilities up against each other, and by far the most important factor is the relative skills of the two pilots. It's widely believed that superior pilot training was the main reason why American F-86 Sabres consistently gained air superiority over technically superior Russian MiG-15s in the Korean War.

Third, even apparently identical fighters can differ enormously in their electronics fit; and in modern fighters, the electronics is at least as important (not to mention expensive) as the airframe. Export versions of fighters are normally much less capable in the electronic sphere than the equivalent models for the home air force, even when the aircraft have the same designation; does anyone expect the F-16Cs exported to, say, Egypt to be anywhere near the capability of the F-16Cs in USAF service? Older aircraft can be upgraded to modern electronic standards at a fraction of the cost of new fighters, an option increasingly popular in these days of tightened defence budgets (for example, the RNZAF recently upgraded its Skyhawk fleet with a radar and avionics suite equivalent to that of the F-16A).

Most of the modern generation of fighters are fairly similar in performance. Leaving out specialised interceptors such as the Tornado and MiG-31 mentioned above, if almost any two modern fighters came up against each other in a dogfight, pilot skill would certainly be the main deciding factor. We can (and certainly will) argue endlessly about the relative merits of, say, F-16 vs Sea Harrier, or F-22 vs Su-35 and there are real differences there; but such technical details are not the most important thing in combat.


Section D.6: Why do some aircraft have gold-tinted canopies?

Gold-tinted canopies have been noticed on the EA-6B and the F-16C/D. On the EA-6B, the coating is a shield against electromagnetic radiation from the Prowler's powerful jamming pods. On the F-16C/D, officially the purpose of this treatment is classified, but it is believe that the gold coating reduces the aircraft's radar signature, by reducing reflections off the complex interior shape of the cockpit. In both cases the coating is a very thin layer of actual gold metal, not a gold-tinted paint.

Other aircraft, such as the F-15E and F/A-18C/D, have a distinct greenish tinge to their canopies. This is a different coating (on the inside of the canopy rather than the outside) that reduces internal reflections to help visibility. Several newsgroup readers report having similar coatings on their glasses, so it's not exactly a secret.


Section D.7: Why do USAF aircraft have tailhooks?

Tailhooks on USAF aircraft do NOT indicate a carrier-landing capability!

The purpose of these tailhooks is to help stop the aircraft in the event of brake failure, or some similar accident leading to a runway overrun. Just past the end of many military runways, you'll find an arrester cable strung across the field. The cable (unlike those on aircraft carriers) isn't attached to anything firm; instead, each end is linked to a long chain, which just drags on the ground. The idea is to slow the aircraft down in a reasonable distance; the tailhooks on Air Force fighters are smaller and weaker than the superficially similar hooks on Navy planes.

The inevitable next question, "Does this mean Air Force planes could land on a carrier in an emergency?", has been discussed at great length. It has been conclusively established that, no, an Air Force fighter could never land on a carrier because, first, its landing gear is likely to break in the much heavier touchdown required for carrier landings; second, even if it could get on the deck in one piece, the weaker Air Force tailhook would break when it caught the Navy arrester cable; and third, even if the aircraft was physically capable of it, Air Force pilots aren't trained in the highly specialised and difficult art of carrier landings.

It has been pointed out that, if the USAF thought there was even the slightest chance of ever being able to save one of its planes by landing it on a carrier, it would have been tested on the mock carrier deck at Patuxent River; the fact that this has never been tried is pretty solid evidence that the Air Force engineers (who would presumably know) are certain it can't be done.

The F-16Ns formerly used by the US Navy as adversaries in training had the standard Air Force tailhooks and undercarriage, and definitely were not carrier capable. These aircraft were stripped so they are as light as possible for the adversary role; making them carrier capable would make them dramatically heavier, if it was possible at all. As non-combat-capable aircraft, there was absolutely no reason for them to land on carriers in the first place.

The RAF pilots who learned to operate from carriers in a few weeks on the way to the Falklands are a different matter entirely; they were flying Harriers, and of course most of the above is irrelevant to VTOL aircraft. Some training was still required, of course, but the requirements are very different, both for the aircraft and the pilots. (As one Harrier pilot put it: "It's much easier to stop and then land, than to land and then try to stop.")

A few land-based aircraft have been flown from carriers with minimal modification, notably the Lockheed C-130 Hercules and U-2. Both of these were fairly special cases involving aircraft designed for very low speeds (and, in the case of the Hercules, rough landings) from the start. See section below for more details..


Section D.8: Can X aircraft operate from a carrier?

Only if it was designed for carrier operations. The presence of an arresting hook on USAF aircraft (see above) does not mean they can land on a carrier. In general, unless a plane was designed to operate from a carrier, it cannot do so.

"Operate from a carrier" includes more than just landing and taking off once. The plane must be able to land and take off hundreds of times, in bad weather, in combat condtions. The plane must be able to communicate with the carrier and the escorts effectively. It must be able to go to sea for many months without rusting away. It must be small, or have folding wings, so it can be stored aboard the ship. It must be designed so virtually all maintainance can be performed aboard ship.

There have been very few instances of a modern (jet) aircraft designed for conventional (runway) operation being adapted for carrier operations. The US Navy's T-45A Goshawk was adapted from a land-based aircraft, but it required a total redesign. The only other example is the Soviet/Russian adaptation of the Su-27 to carrier operations--but that aircraft only makes arrested landings, not catapult takeoffs.

In general, making an aircraft carrier capable would require stronger landing gear (for arrested landings and catapult launches), a reinforced aft airframe for the arresting hook, folding wings and vertical tail, "navalization" of the airframe to avoid corrosion, lower approach and takeoff speeds, new communications and computer systems (i.e. Automatic Carrier Landing System), and many detail changes to match existing naval equipment. In short, a complete and total redesign of the aircraft, from the airframe down to the smallest detail components. The cost would be similar to the cost of designing a totally new aircraft.


Section D.9: Did a C-130 land on a carrier? How about a U-2?

Yes.

On 30 October 1963, a USMC KC-130F made several carrier landings and take-offs on the flight deck of USS Forrestal, in a series of tests intended to determine whether it would make a good COD (carrier on-board delivery) aircraft. The only modification was an anti-skid braking system. The aircraft made several landings and take-offs, with no use of arrester gear or catapults, and performed well (the pilot, Lieutenant James H Flatley III, was awarded the DFC for his part in the tests). However, it turned out that the Hercules would have been unable to fit in a carrier's hangar deck, so the smaller Grumman C-2 Greyhound was developed instead.

Modifications to the U-2 involved the addition of an arrester hook and a strengthened landing gear (the U-2 already had folding wings). In 1964 two modified U-2As, designated U-2G, were flown from USS Ranger and USS Kitty Hawk; the tests were successful, and several modified aircraft were apparently flown from carriers by the CIA during the 1960s (the service version may have been designated U-2J). In 1969, a similarly modified U-2R was flown from USS America, but this does not seem to have led to any service use.

For more information about U-2 operations from carriers, see http://www.history.navy.mil/faqs/faq77-1.htm.


Section D.10: The composition of an aircraft carrier's air wing


Section D.11: Why do the USAF/USN use incompatible refuelling systems?

By far the most common method for in-flight refuelling is the "probe-and-drogue" system, in which the tanker unreels a hose behind it with a drogue on the end (a meshwork cone whose drag keeps the end of the hose in a stable position). The receiving aircraft has a probe attached to it, which is inserted into the drogue to link the fuel systems. Some receiving aircraft have probes permanently mounted, some have bolt-on probes that can be attached if a mission requires them, and some have retractable probes. This method is used by the US Navy, modern Russian aircraft, and every other country that uses in-flight refuelling, except some Isreali aircraft.

The US Air Force uses the "flying-boom" system; Israel also uses this system for some aircaft. In this system, a rigid boom, with control surfaces on the end, is extended from the tanker and inserted into a socket on the receiving aircraft. This method has two major disadvantages over the probe-and-drogue method. First, the boom has to be attached directly to the tanker's fuselage, which prevents refuelling from detachable pods attached to a tanker's wings (allowing more than one receiver to link up at a time) or to the centreline hardpoint on a fighter or strike aircraft (allowing such aircraft to refuel each other without a dedicated tanker), both of which are commonly done with probe-and-drogue refuelling. Second, the equipment on the receiving aircraft is incompatible with the probe-and-drogue system, which means that USAF aircraft can neither refuel nor receive fuel from any other aircraft, including the US Navy's.

The reason why the USAF puts up with this is that the flying-boom system can achieve much greater fuel flow rates than the probe-and-drogue system (mainly because the rigid boom is shorter and wider than the flexible hose). This is mainly for the benefit of large bombers such as the B-52 and B-1; refuelling such large aircraft by probe-and-drogue would take much longer, enough (in the USAF's judgement) to cause significant tactical problems. Few other air forces operate aircraft of similar size; the handful that do are prepared to live with the refuelling delays in the interests of compatibility.

USAF KC-10s are fitted with a permanently-installed probe-drogue refuelling capability. Also, KC-135s may be configured for probe-drogue refuelling, but they cannot use the flying boom method while so configured.

The third refuelling system used is the "wingtip-to-wingtip" system, used only by older Russian bombers. In this system, a hose is unreeled from one wingtip of the tanker, and caught by a socket in the opposite wingtip of the receiver; the two aircraft then fly side by side, with the hose joining their wingtips (the length of the hose is comparable to the wingspan of the aircraft). The tankers are all converted bombers (Tu-16 Badgers) themselves, and Tu-16 Badgers are the only bombers to receive fuel this way. This system is very tricky to link up, occasionally dangerous, only usable with bombers (smaller aircraft can't carry the necessary receiving equipment on their wingtips), and gives flow rates even worse than probe-and-drogue; not surprisingly, the Russians have largely replaced it with the probe-and-drogue system, and it will probably become extinct with the retirement of the last Tu-16 Badgers, tankers and bombers both.


Section D.12: Aircraft designations

Complete discussion of aircraft designations is beyond the scope of this FAQ. See the rec.aviation.military FAQ, part H, for detailed discussion. That document covers the following topics:

        H.1.  American aircraft designations
        H.2.  US Navy aircraft designations (pre-1962)
        H.3.  USAF/USN fighters and attack aircraft
        H.4.  American missile designations
        H.7.  American electronic systems designations
        H.6.  Russian aircraft designations
        H.7.  Russian aircraft codenames
        H.8.  Russian missile designations and codenames
        H.9.  British aircraft designations
        H.10.  Canadian aircraft designations
        H.11.  Chinese aircraft designations
        H.12.  German aircraft designations (WW2)
        H.13.  Japanese aircraft designations and codenames (WW2)
        H.14.  Swedish aircraft designations
Also see the Acronyms, Codenames and Designations FAQ.

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