Clipping the Bearcat's wing

Flight Journal, Aug 1998 by Meyer, Corky

It's fascinating what the mind remembers and what it doesn't. I can't remember what I had for breakfast yesterday, but some test flights stick in my mind as though they happened this afternoon. The flights in which I was paid to intentionally break large parts of the wing off Grumman Bearcats while in the air and then land minus more than 20 percent of the wing and half of the ailerons are among those. I remember every aspect of the Bearcat program in infinite detail. A few folks have marveled that I have such a retentive memory. But, when one was a 24-year-old bachelor who was paid for flying experimental fighters and hadn't yet discovered girls, such events are indelible in the mind's eye.

The concept of purposely blowing large portions of an aircraft's wing off in flight would appear to be pure insanity until you examine the nature of the time when the Bearcat was in its gestation period.

By late 1942, it had become clear to the Navy that the Grumman Hellcat was a great improvement in fighter performance when compared to the vaunted Japanese Zero fighter. But newer enemy aircraft that would have much increased horsepower and improved performance were being developed. All students of aerial warfare know that the fighting life of any weapon in wartime is limited, so a replacement for the Hellcat would be needed sooner rather than later.

Development of engines in mass production, like the Pratt & Whitney R-2800 2,000hp engine used in the Hellcat, could be easily synchronized with new aircraft design. However, it would have been, and was, on all too many occasions in WW II, imprudent to count on an experimental engine to come to fruition either in time or in sufficient quantity for a new aircraft design. The engine had to pass its first official, full-power, 150hour ground-test demonstration before it could even be considered for a new plane. Passing that critical test was a very minimum requirement for an aircraft company or the government to give the go-ahead for mass production of a new engine or aircraft. It was clear that to get a further increase in performance, designers would have to produce smaller and lighter airplanes utilizing engines that were currently in production and hope for engine-performance improvements later on in their production runs.

In early 1943, Grumman officials were invited to England to see the captured fighters of the Axis powers and to fly some of them. The test team included: Leroy Grumman, president of Grumman and test pilot during and after WW I; Bud Gillies, vice president flight operations and a test pilot current in all American airplanes at that time; and Bob Hall, chief engineerexperimental, a famous test pilot of Grumman and other airplanes of the Gee Bee era.

Of all the airplanes they saw, they were most fascinated with the Focke-Wulf 190. It not only offered sprightly performance, but it also had excellent flight characteristics with a gross weight of 8,750 pounds and only 1,730hp. The Hellcat was 3,200 pounds heavier with just 270hp more. Both Gillies and Hall evaluated the Fw 190 and found it to be the aircraft they would have liked to have designed themselves. It was exactly what the Hellcat follow-on aircraft should be. The only things the Fw 190 lacked were a good gunnery-lead computing angle of vision over the nose and a structure that would withstand carrier operations.

The Focke-Wulf impressed them so much they felt compelled to hurry home and put together an airplane of this gross weight in time for the water-injected Pratt & Whitney R-2800 C model engine of 2,400hp (War Emergency Power) to be installed. This would give our naval aviators a big performance increase over the newer Japanese fighters and would still retain the proven performance of the P&W R-2800 series production engines installed in the Hellcat.

The F8F design was started immediately on the trio's return. Mr. Grumman took a direct hand in its design. As the design progressed, it became obvious that meeting the 8,750-pound gross weight of the Focke-Wulf would be difficult. The structure required to withstand the loads encountered during carrier operations hadn't been required in the Fw 190 and would impose significant weight penalties on the new design.

Innovative measures were needed to meet the stringent goals that Mr. Grumman and his team were striving for. Many items considered standard equipment would have to be sacrificed, including a reduction in the number of guns from six to four, a reduction in fuel capacity from 250 gallons to 185 gallons and the elimination of the adjustable seat. The seat would be integral to the structure, and cushions or the parachute-either seat or backpack-would be used for seat adjustment The wing-fold mechanism would have to be simpler than the Hellcat's and would be moved to the outer portion of the wing to save weight. A single rather than a three-tank fuel system would simplify the airplane and reduce its weight.

Even with all this ingenuity, the bogey of 8,750 pounds was still unattainable. Finally, Pete Ehrlendsen, chief of structures, came up with a far-out but intriguing idea to save about 230 pounds of wing structure-a large chunk of the weight savings necessary to meet the goal.