Paris Air Show

LM defends F-35 JSF agility against critics

 - June 5, 2009, 7:03 AM

Is Lockheed Martin’s Joint Strike Fighter a “bomb truck,” optimized for the stealthy attack of ground targets but of limited value as a defender of airspace? Critics and rivals of the multibillion-dollar international program have been sniping at the F-35’s air-to-air maneuvering performance for years. But the issue came to a head last August, when a presentation from The Rand Corporation stated that the F-35A “can’t turn, can’t climb, can’t run.”

Coming from a respected think tank that is funded by the U.S. government, the claim provoked a heated response from the Pentagon. “The F-35 enjoys a significant combat loss exchange ratio advantage over the current and future air-to-air threats,” said U.S. Air Force Maj. Gen. Charles Davis, the F-35 program executive officer. Rand subsequently backtracked on the presentation, but the issue was still reverberating ahead of the Paris Air Show when AIN sought comment from Lockheed Martin F-35 chief test pilot Jon Beesley.

“I’m not sure I believe some of the Rand figures. They are influenced by the lightweight fighter mafia,” he commented. That’s a reference to a school of opinion that championed the original F-16 concept, and chafed at its subsequent development into a much heavier, multirole combat aircraft. Twenty-five years later, the “mafia” still apparently haunts the halls at Lockheed Martin’s Fort Worth, Texas facility.

But Rand authors John Stillion and Scott Purdue contended that the high wing loading of the F-35 makes it inherently less agile than current fighter aircraft, including Russia’s MiGs and Sukhois, and Europe’s Rafale and Typhoon. Moreover, the F-35’s thrust loading is significantly inferior to that of the F-15, F-16 and F-22, they said. As a result, Rand alleged, the F-35 is inferior in visual-range combat in terms of acceleration, climb and sustained-turn capability. It also has a lower top speed, they added.

Beesley called these comparisons naïve and simplistic. An empty F-35A will weigh 30,000 pounds and have a maximum thrust of 40,000 pounds, he noted. “Even when you add the 1,200 pounds of our air-to-air combat load and the 9,000 pounds half-fuel load with which you would typically begin an air-to-air engagement, then our power-to-weight ratio is still almost 1:1.” Moreover, he noted, the F-35’s half-fuel load is greater than today’s fighters. An F-16 would have only 3,600 pounds.

Beesley also insisted that the sustained turn rate of the F-35 is conquerable, despite its higher wing loading. He insisted that there is “a huge amount of thrust available” from the aircraft’s Pratt & Whitney F135 engine, which is the most powerful ever fitted to a combat aircraft.

The F-35 chief test pilot further noted that the F-35 can fly at angles of attack that are just as steep as those of the F-18 or the F-22. “It’s a fully maneuverable 50-degree airplane,” he said. He invited those who had witnessed the F-22’s startling agility at airshows recently to ponder the fact that “the same people also designed the flight control system for the F-35.”

Moreover, Beesley told AIN, the debate should not be limited to a discussion of visual-range dogfighting. “In a real combat mission, the ability to sneak up on your opponent and be the first to shoot is paramount,” he said.

This is a reference to stealth, of course, and the F-35’s low observability cannot be matched by any of the fighters that were mentioned in the Rand analysis. Opposing fighter pilots will find that the range at which they can detect the F-35, either by radar or electro-optics/infrared means, will be much shorter than they are used to.
But Beesley also had another “non-kinetic” characteristic in mind–the F-35’s mission avionics, claimed to be the most advanced in the world. “The F-35 pilot will have superior situational awareness, by day and by night, and a helmet-mounted display. This will be a great advantage and will allow him to take full advantage of the performance of today’s off-boresight air-to-air missiles,” he said.

Beesley can speak from some experience in the debate. He has more than 5,500 hours of flight time in over 50 different aircraft, including the F-16, F-117 and the F-22. He also flew Soviet-era fighters during a tour with the USAF “Red Hats” squadron in 1979-80.