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Eurofighter a shooting star in clash with US jets

IT might be over budget and years late but the Eurofighter Typhoon has shown that it can shake off America's best fighter plane and shoot it down.

A chance encounter over the Lake District between a Eurofighter trainer and two F-15 aircraft turned into a mock dogfight, with the British plane coming off best - much to the surprise of some in the RAF. The episode was hushed up for fear of causing US blushes. For a project 10 years late and $8bn over budget, it is a welcome piece of good news.

The 'clash' took place last year over Windermere when the two-seater RAF Eurofighter was 'bounced' from behind by the two F-15E fighters. The US pilots intended to pursue the supposedly hapless 'Limey' for several miles and lock their radars on to it for long enough so that if it had been a real dogfight the British jet would have been shot down. But much to the Americans' surprise, the Eurofighter shook them off, outmanoeuvred them and moved into shooting positions on their tails. The British pilots themselves were almost as surprised at winning an encounter with an aircraft widely regarded as the best fighter in the world.

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In an effort to improve the reliability and maintainability of the F 22 A, the USAF bugdetes 102 million $ in fiscal years 2006/ 2007. The F 22 A continues to be below its expected reliability rates....

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The F-35’s ability to win an air-to-air engagement is drawing increased attention as the U.S. military and industry’s focus includes expanding the Joint Strike Fighter’s customer base beyond the core purchasing nations.

For years, prime contractor Lockheed Martin seemed content to promote the F-35’s “strike fighter” capabilities, if only to avoid competing against its other major fighter program, the F-22 Raptor. But with the F-22 not exportable, Lockheed Martin seems keen to talk up the F-35’s air combat skills to bolster its chances for new foreign military sales—namely, to Japan, Turkey and Greece.

The contractor tells Aviation Week that the JSF’s combination of stealth, multisensor situational awareness, advanced pilot-machine interface and basic aeromechanical performance make it a credible fighter aircraft, too. That is key to several other customers, who cannot afford the so-called high-low fighter mix on which the U.S., U.K. and Italian air forces are planning.

But Lockheed Martin is focusing largely on the beyond-visual-range fight, with ranges greater than 18 naut. mi. that executives say will represent 62% of all aerial combat. Another 31% of engagements would fall into the 8-18-naut.-mi. transition range, and just 7% of fighting would be close-in combat where the airframe is stressed the most.

Lockheed Martin says it ran the F-35 through the Pentagon’s TAC Brawler simulation for air combat systems analysis, using what would be the “ideal” air combat configuration, taking the conventional-takeoff-and-landing F-35A, the only model designed to perform full 9g maneuvers.

The aircraft can also reach a 55-deg. angle of attack in trimmed flight, while most fighters, excluding the F/A-18, are limited to 30 deg. The exact performance of the current F-35A configuration—also known as the 240-4—are classified. But a similar earlier standard (240-3) was credited with a maximum speed of Mach 1.67; acceleration from Mach 0.8 to Mach 1.2 at 30,000 ft. in 61 sec.; a top turning speed of 370 kt. at 9g and 15,000 ft.; and a sustained turn capability of 4.95g at Mach 0.8 and 15,000 ft. Moreover, an aircraft with those performance figures would carry two beyond-visual-range AIM-120 Advanced Medium-Range Air-to-Air Missiles (Amraams) in the internal weapons bay.

Yet, such performance numbers appear to leave the F-35 short of the kind of air-to-air capabilities provided by other combat aircraft, such as the Russian Su-30MKI or the European Typhoon. And even Lockheed Martin test pilots concede that the F-35—although offering very high initial acceleration due to its powerful 42,000-lb.-thrust F135 engine—could start losing advantage at higher speed and altitude. This might be partly due to the aircraft’s large frontal area, which is designed to allow internal weapons carriage—meaning in a traditional quick-reaction intercept role, the F-35 may not be able to match rivals.

Nevertheless, Brawler modeling showed the F-35 could achieve a loss-exchange ratio better than 400% against its nearest “competitor,” according to Lockheed Martin executives. They demur about naming the competitor, but their comparison charts indicate it is the Sukhoi Su-30 or Typhoon.

That engagement ratio comes from the combination of F-35 characteristics, executives argue, including stealth, the performance of the APG-81 active electronically scanned array radar, sensor fusion using data links and the 360-deg. situational awareness afforded by the distributed aperture system of infrared and electro-optical sensors and electronic support measures.

In the meantime, and without discussing specific performance characteristics, Italian air force fighter pilots involved with the F-35 program tell Aviation Week that the aircraft’s performance falls “between the F-16 and the F/A-18 in terms of flight envelope—and is actually closer to the F/A-18, considering its high angle of attack and slow-speed maneuvering capabilities.”

The F-35A, with an air-to-air mission takeoff weight of 49,540 lb., has a thrust-to-weight ratio of 0.85 and a wing loading of 110 lb. per sq. ft.—not ideal for a dog-fighter. The F135 engine delivers 42,000 lb. thrust, and industry officials suggest that an F-35 entering an air-to-air engagement with 40%—or more than 7,275 lb.—of internal fuel will have a thrust-to-weight ratio of 1.09 and a wing loading of 83 lb. per sq. ft. Those figures describe an agile, albeit not top-end, fighter.

Still, one key feature, Lockheed Martin executives stress, is the very low observability designed into the JSF. Whereas the F-35 would carry its weapons internally, the Typhoon, Su-30, Saab Gripen or Dassault Rafale carry their missiles externally, thus increasing their radar signatures and degrading their on-paper air-to-air performance. The F-35 also accommodates more internal fuel, 8.3 tons, giving it greater endurance potential without external fuel tanks that would affect radar signatures.

Nevertheless, the F-35 may have notable weaknesses for pure air-to-air combat. For one, it is not designed to conduct engagements in a high-speed, high-altitude, sustained turning environment. Its high-speed cornering capability should help it to dodge an adversary’s beyond-visual-range missiles, though, particularly if German and U.K. air-to-air simulations on the kill probability of modern medium-range air-to-air missiles are accurate.

Those figures are part of the rationale for countries pursuing the ramjet-powered MBDA Meteor missile to supplant Amraams. Yet even in the Amraam world, Typhoons may have an edge over the F-35, since they could launch the missile at higher speed. Sukhoi Su-30s and the future T-50 are also being designed to maximize air-to-air missile performance that way.

Finally, while Lockheed Martin touts F-35 stealth as an advantage, it has its drawbacks, as well. The aircraft’s payload is limited as long as it wants to preserve its low-observable signature through internal carriage. That means having only four AIM-120s at its disposal. A study now underway could boost that total to six Amraams. Other weapons, including infrared-guided air-to-air missiles, would be carried externally, with plans for a “stealthy” JSF adaptation using a low-signature pylon design. Still, the radar signature would increase, as would drag, further reducing the F-35’s potential.

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Kritiker des Programms nennen unter anderem folgende Punkte:

* Der JSF leide unter falsch definierten Entwicklungszielen.
* Er führe zu wenig internen Treibstoff und Waffen mit und kann daher kein Ersatz für Bodenangriffsflugzeuge sein.
o F-35 verfügt über lediglich vier interne Waffenpositionen, die nur Luft-Luft-Raketen und Bomben mit maximal 2 x 900 kg aufnehmen können.
o Um das Angriffspotential zu erweitern, müssen zusätzliche Außenlasten an den Tragflächen angebracht werden, wodurch die Tarneigenschaften reduziert werden.
* Die Unfähigkeit zu langen Überschallflügen macht den F-35 als Luftverteidigungsplattform weniger brauchbar.
o Die geringe Höchstgeschwindigkeit (Mach 1, schränke die Einsatzpalette zudem erheblich ein.
* Das Projekt werde unter längeren Verzögerungen leiden und seinen Kostenrahmen sprengen .
o Die Kosten des Flugzeugs seien per se zu hoch.

Trotz dieser Bedenken haben inzwischen mehrere Länder Vertrauen in das JSF-Design ausgedrückt und wurden zu Minderheits-Partnern im JSF-Herstellerkonsortium.

Die Fürsprecher des Programms sehen den JSF als Möglichkeit aus dem Jahrzehnte alten Muster der US-Flugzeugbeschaffung auszubrechen: Anstatt traditionell drei Flugzeuge, für jede Waffengattung eines, zu entwickeln, ist der JSF ein Gemeinschaftsprojekt der drei US-Teilstreitkräfte Luftwaffe, Navy und Marine Corps. Dies erlaubt, dass die verschiedenen JSF-Varianten zu 80% identisch sind, und senkt so die Flugzeug- und Wartungskosten. Das Projekt folgt dabei zum Teil der Philosophie der Europäer, deren Panavia Tornado von Anfang an als „Multi-Role Combat Aircraft“ (MRCA) geplant wurde und dabei erfolgreich war. Der JSF ist außerdem das erste US-Flugzeugprogramm, bei dem die Kosten als unabhängige Variable angesehen werden. In früheren Programmen waren die Flugzeugkosten eine abhängige Variable – zusätzliche Fähigkeiten haben immer die Stückkosten erhöht. Solche Design-Änderungen werden während der JSF-Entwicklung nicht erlaubt, das bedeutet, dass der Budgetrahmen begrenzt bleibt.

Ursprünglich war die US Air Force von einer Fertigungsrate von 110 Maschinen pro Jahr für die F-35A ausgegangen. Diese Fertigungsrate wird benötigt, um die im Laufe der Zeit außer Dienst gestellten F-16 rechtzeitig zu ersetzen. Nunmehr ist nur noch eine Produktionsrate von 48 Maschinen pro Jahr, ab dem Jahr 2012, geplant. Dadurch steigt der Stückpreis pro Maschine deutlich an. Einige Analysten sehen schon die 100-Mio-US$-Marke pro Maschine überschritten.Im April 2007 gab das Verteidigungsministerium der USA bekannt, dass der Preis pro F-35 sich auf 121,97 Mio. US$ pro Maschine erhöht. Laut einem Bericht des Rechnungshofs des Kongresses vom März 2008 soll das gesamte Programm die US-Streitkräfte in den nächsten Jahrzehnten fast eine Billion US-$ kosten. Davon entfallen auf die Entwicklung und Anschaffung von 2.458 Flugzeugen 300 Mrd., auf Betrieb und Unterhalt in den nächsten Jahrzehnten weitere 650 Mrd. Dollar.

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By Jim Wolf

WASHINGTON, Nov 20 (Reuters) - The U.S. Air Force fleet of F-22 Raptors, designed to be the world's top fighter jet, needs more than $8 billion dollars of upgrades to be made "capable and affordable to operate," the Pentagon's top arms buyer said on Thursday.
The comments by John Young, the undersecretary of defense for acquisition, highlighted Pentagon opposition to buying more than the 183 F-22s on order from Lockheed Martin Corp (LMT.N), the prime contractor.
The Air Force long has argued it needs 381 F-22s to be able to dominate the skies at the start of any major war and clear the way for other U.S. and allied warplanes.
Young said the Air Force already had budgeted about $8.3 billion for software upgrades and unspecified modifications to about 100 of the F-22s that would otherwise "kind of be lesser models."
Those outlays should be taken into account before talking about buying more jets, he told reporters at a breakfast.
"I don't think the debate is informed by all those facts," he added.
In addition, the F-22's "mission capable rate," a measure of its readiness, fell in the 62 percent range in the 2008 fiscal year, Young said.
"I think that's troubling," he went on, adding the fighter, which features advanced technology to reduce detection by radar, "is proving very expensive to operate."
Christopher Bolkcom, an expert on warplanes at the Congressional Research Service, said the mission capable rate was an incomplete gauge of an aircraft's availability.
"As a rule of thumb, however, 62 percent is unsatisfactory," he said.
Young said there were also struggles with low-observability and other issues that he did not name.
"Clearly, (there's) work to be done there to make that airplane both capable and affordable to operate," he said.
The F-22 had failed to meet most of its "key performance parameters" in operational tests last year and the trend was negative. Maintenance manpower hours per flying hour had gone up since previous tests, with the last one a "substantial" increase, he said.
Lockheed Martin, which has delivered 131 F-22s to the Air Force, declined to comment on Young's remarks, referring calls to the Air Force, which did not immediately respond.
The Pentagon last week released $50 million in bridge funds to preserve a decision on future F-22 production for the incoming administration of President-elect Barack Obama.
The production line must start shutting down early next year unless Obama opts to buy another batch.
Lockheed produces the F-22 aircraft in partnership with Boeing Co (BA.N) and United Technologies Corp's (UTX.N) Pratt & Whitney, which builds its dual F-119 engines.

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WASHINGTON — Defense Secretary Robert Gates says the Pentagon will end the F-22 fighter jet and presidential helicopter programs run by Lockheed Martin Corp.
Military analysts widely expected the radar-evading supersonic jet — considered an outdated weapon system designed for the Cold War — would not go beyond the 187 already planned. The planes cost $140 million each.
But Bethesda, Md.-based Lockheed, the nation’s largest defense contractor, has said almost 95,000 jobs could be at stake if the Pentagon didn’t buy more of the planes.