Author Topic: XF6F-3: (Read 923 times)

Shuckins · « **on:** June 25, 2006, 02:44:33 PM »

An article by Warren M. Bodie in the special summer edition of Flight Journal featuring the F6F Hellcat mentions that the XF6F-3 prototype, which was the first to be fitted with the Pratt and Whitney R2800-10, was clocked on one test flight at a speed of 398mph at sea level.

Anyone else have any information about this? I assume that the prototype made this flight sans military equipment and hardware.

Or is this a misprint?

Regards, Shuckins

bkbandit · « **Reply #1 on:** June 25, 2006, 07:38:47 PM »

This could be as right as rain, i doubt a htc would do nothin. I have read from alot of different sites and watch tons of documentarys, htc doesnt agree with alot of them.

Oleg · « **Reply #2 on:** June 26, 2006, 01:14:43 AM »

This is best speed at altitude for sure, not at sea level.
La7 has ~385mph at sea level with WEP.

Soulyss · « **Reply #3 on:** June 26, 2006, 09:50:14 AM »

I haven't read the article... but I wonder if 398 sea level could be done w/ a prototype aircraft... did the XF6F-3 have all the combat provisions loaded? ie, guns, ammo, pilot armor, self sealing tanks, etc. Seems like when I read about prototype aircraft they often show impressive speeds and climb rates... but those numbers end up coming way down when the plane is actually outfitted for combat.

Treize69 · « **Reply #4 on:** June 26, 2006, 01:00:03 PM »

Yeah, every little change in the airframe or loadout has an effect on the performance of the plane. Even whatg seems like t would be good can be bad, and vice versa. For example-

Recommended changes to the airframe of the XP-38 and it effect on airspeed:

Redesign Prestone Coolant Radiators..... +8 MPH
Improve blower installation..... +4 MPH
Non-Retracting Oil Cooler Inlet..... +3 MPH
Reduce size of exhaust cooling duct..... +2 MPH
reduce weight by 800-1,000 pounds..... +2 MPH
Increase H-stab area by 7sq.ft...... -1.2 MPH
Add armament..... -7.8 MPH

Net Gain..... +10 MPH

With provisions for external stores added (something the 38 wouldn't get for several years), the weight of 6MGs and ammo, full combat loadout of fuel, armor, radio equipment, not perfectly tuned experimental engine, I can see speed dropping by 30-40 MPH.

Shuckins · « **Reply #5 on:** June 26, 2006, 05:12:50 PM »

With the airframe stripped of all combat equipment, and the fuselage and wings highly polished for minimal drag, it might be possible.

Armament and ammunition load added about 800 pounds to the F6F.

Draining the wing tanks and operating with only half a fuel load in the fuselage tank would trim another 700 pounds.

Power to weight ratio goes up considerably. If the prototype can get off the ground for a single high-speed run at a weight of 9,500 lbs., the power to weight ratio would be about 4.75 lbs. per horsepower

The normal fighter load for a Hellcat with full internal fuel, no drop-tank, and full ammunition load was 12,213 lbs...yielding a power to weight ratio of about 6.11 lbs. per horsepower.

Grumman data claimed that the F6F-5, using water-injection, could hit 350mph at sea level.

F4UDOA · « **Reply #6 on:** June 30, 2006, 09:35:54 AM »

I would say that is a misprint.

The XF6F-3 did not even have water injection. The production model was rated for approximately 315MPH at sealevel.

398MPH is the speed of a P-51D with 150Octane fuel at sea level.

Debonair · « **Reply #7 on:** June 30, 2006, 02:30:19 PM »

P-51D can do well over 500MPH @ 5051' MSL unarmed

yeah, i edited this post, thats just how i roll

F4UDOA · « **Reply #8 on:** June 30, 2006, 06:59:29 PM »

I mean a wartime P-51D at sea level.

Reno racers do lap speeds at 50' close to 500MPH. But of course that is at 120" of MAP.

Debonair · « **Reply #9 on:** June 30, 2006, 08:06:07 PM »

lol, yeah, Dago Red, thats the P-51d i was talking about rofl...
...btw iirc it was somewhere over 130"

Squire · « **Reply #10 on:** June 30, 2006, 08:55:11 PM »

398 mph top speed, clean, at altitude, is more than likely for an XF6F-3. All prototypes fly faster than the production fighters do. Without water injection and 115/145 fuel, there is no way it would have done that at sea level, or even close.

Reno Air Race a/c have as much to do with WW2 fighters as F-16s do. They are stripped down, re engined monsters that are engineered to run waaaaaay past their original specs, for a very short race. Its no different than comparing a NASCAR race car and your family sedan.

F4UDOA · « **Reply #11 on:** July 05, 2006, 10:01:57 AM »

Just thought I would post on of my favorites.