By Tommy H. Thomason

Thursday, February 5, 2015

Goodyear F2G Corsair: Kamikaze Killer?

The F2G was a Corsair developed by Goodyear and powered by the Pratt & Whitney R-4360, a four-row, 28-cylinder radial engine instead of the R-2800, two-row, 18-cylinder engine of the stock Corsair, roughly a 50% increase in horsepower. The advantage dropped somewhat with altitude, however, because the R-2800 had a two-stage supercharger and the R-4360 in the Corsair, only a single stage. And because the F4U-4 was about 650 lbs lighter with full internal fuel, it wasn't at much of a disadvantage from a speed or rate of climb standpoint even at sea level.

It is usually written that the F2G was created to counter the Kamikaze tactic that the Japanese introduced in the Pacific, first recognized in October 1944. If so, someone was prescient, since the decision to install an R-4360 in the Corsair had been made well before that. Pratt & Whitney used two F4U-1s for R-4360 for engine testing. The first one was for ground runs only, which began in May 1943. The second first flew on 12 September 1943.This picture was taken to illustrate the difference between the R-4360 configuration (referred to as F4U-1 WM for Wasp Major) and the R-2800 one:

Goodyear got a contract in March 1944 for 418 F2G-1s and 10 F2G-2s. The -2s were to be fully carrier-basing compatible. Don Armstrong flew the first FG modified with the R-4360 on 26 August 1944. So strictly speaking, the F2G's raison d'etre was not to counter the Kamikaze tactic, at least not originally. (My tongue-in-cheek explanation is that someone in BuAer wondered how fast a Corsair would go when powered by the humongous R-4360.) The F2G apparently was really intended to be supplied to shore-based Marine squadrons, as almost all of the order was for the -1 that didn't have a tail hook or powered folding wings.

In any event, only 10 F2Gs—five land-based -1s like BuNo 88454 in the first picture and five carrier-capable -2s—were built along with several Corsairs modified for flight test of the configuration. The Navy had elected to equip itself with the Grumman F8F Bearcat instead.
One XF2G was flown with a lower aspect-ratio vertical fin that replaced the side area lost by the change to the upper aft fuselage to accommodate the bubble canopy. (The rudder was not changed.)

Goodyear decided instead to add a 12-inch plug to the bottom of the fin, which also provided for the addition of an auxiliary rudder for additional yaw-control power during a waveoff or go-around at low speed.
The auxiliary rudder deflected 12.5 degrees right when the flaps were more than 30 degrees down. (Full flaps was 50 degrees; recommended takeoff flap setting was 20 degrees.) The main rudder deflected 7 more degrees to the right than to the left.

Note that the picture on the left is an early F2G-1, which were delivered without a tail hook; the picture on the right is an F2G-2.


Anonymous said...

After returning from a combat tour in Italy with the AAF during WW2, my father was stationed at Bradley Field north of Hartford, CT as an instructor pilot for the P-47N program.
He tells of a time when he met one of these "stretched out corsairs" at 20,000 ft, pulls along side and gives the 'high sign'. Both pilots rolled on the throttle, and that Corsair just flat left him.

Chris, NC

Rick Morgan said...

It obviously flew, but Wouldn't more rudder area be a good idea to handle the extra torque?

Tailspin said...

Rick - as a matter of fact, it was a good idea. I've added that change to the post.



Anonymous said...

Interesting to learn that the aux. rudder was not used in the take off configuration with 20 degrees flap. Obviously the heightened fin served that purpose well. Any flap deflection past 30 degrees would deflect the aux rudder so that would accommodate a carrier take off with full flaps. If I read this correctly the aux rudder only had 2 settings; streamlined and deflected 12.5 degrees, so it was not a movable control surface like a true rudder and functioned more like a 2 position trim tab? Pat D.

Steve said...

I just discovered your blog. Great info!

Tailspin said...

Two-position trim tab is my understanding.