Author Topic: New data posted (Read 1210 times)

F4UDOA · « **on:** March 01, 2001, 09:44:00 AM »

Gents,

I have posted the data in PDF format on my web page. Here is the URL

http://members.home.net/markw4/MSWF4UDATA.pdf

It is 6 meg so I cannot e-mail to anyone as I had promised. It's 29 pages long, all in img format, not text. I listed them in the order of the report so the data is spread through out the report. It gives comparisons to these A/C.

F4U's
-1
-3
-4 <== Oct 1944 and revised April 1945
-5
F2G-1

F6F-5
F7F-1
F8F-1
P-51B <==only
P-47D
P-38J

Enjoy!!

Pyro,

If your going to model the F2G, F8F, F7F or especially the F4U-4 please look at these docs.

wells · « **Reply #1 on:** March 01, 2001, 10:10:00 AM »

Thanks DOA!

[This message has been edited by wells (edited 03-01-2001).]

Westy · « **Reply #2 on:** March 01, 2001, 10:59:00 AM »

Got it. Thanks!!!!

-Westy

F4UDOA · « **Reply #3 on:** March 01, 2001, 11:50:00 AM »

If anybody is having trouble reading some of the text let me know. It is a little easier reading the paper docs.

Later
F4UDOA

Vermillion · « **Reply #4 on:** March 01, 2001, 12:04:00 PM »

All I can say is.....
SWEET!

Real F2G data.... wow!

------------------
Vermillion
**MOL**, Men of Leisure

Zigrat · « **Reply #5 on:** March 01, 2001, 12:15:00 PM »

real axcellent f4udoa

looks like teh f4u in aces high pretty well modeled,but the p47 is getting sorely shafted in its speed at low level.

F4UDOA · « **Reply #6 on:** March 01, 2001, 01:40:00 PM »

Zig,

Yeah, the P-47 they tested is a fast bird. It's weight was only 14,000lbs so I wonder what varient it was? I think it was a D20 with a uprated engine to 64" of manifold. The only thing about the F4U-1 that could be changed in AH is the climb. Notice the initial climb at military power is 3K per minute. It's about 2700fpm in AH.

But the thing that stands out for me though is the stall speeds and drag numbers. The stalls in AH are all to high

P-51B=.017
F8F-1=.019
F4U-1=.020
F7F=.020
P-47D=.022
F6F-5=.023
P-38J=.028

The F4U numbers are broken down in detail including cooling drag. Niklas had mentioned a while ago that he didn't thing a F4U could really do 360mph on the deck because the drag was to high. I guess there is the answer.

Also the numbers on the F4U-3 are amazing.
487MPH at 27,500FT and 378 ot sea level. And that was a production bird BTW with 30 being built and delivered. It is amazing that the F2G has gotten so much attention over the years when the F4U-3 actually had better performance above sea level, while the F2G had a top speed of 397MPH on the deck and only 426MPH at alt. when the power curve fell off.

Fishu · « **Reply #7 on:** March 01, 2001, 01:50:00 PM »

I think that fuel octane has been swapped over with N1K2 and F4u

obviously F4u needs higher octane which N1K has and N1K needs low octane from f4u...

Sable · « **Reply #8 on:** March 01, 2001, 02:04:00 PM »

Well those stall speeds are all recorded at -3/4 fuel and -3/4 ammo. Given the CLmax's you would get from them, and that they are trying to simulate landing conditions, I think those are flapped stall speeds anyway.

Sable
352nd FG

F4UDOA · « **Reply #9 on:** March 01, 2001, 02:59:00 PM »

Sable,

I am sure they are all flapped speeds but not all at landing weights and not powered stalls either.

Look at page 27 on the F4U-1 performance. It list the power off stall for the F4U-1 as 89MPH with a Cl max of 1.90(correct for F4U-1 NACA full flap). Then compare that too this doc dated Aug.1944

http://www.geocities.com/slakergmb/id73.htm

Listing the Gross weight (12,000lbs) stall at 87.5mph and the empty stall at 82.2mph power off. And it matches almost perfectly with the note that it is power off. Also the F4U-1 pilots manual list the power on full flap stall at 66Knots or 76MPH.

Regardless of this the stalls of all of the A/C listed in the report are to high in AH especially with flaps. An issue I have brought up many times in the past. That is flaps are not creating enough lift.

Later
F4UDOA

Sable · « **Reply #10 on:** March 01, 2001, 03:41:00 PM »

Ahhhh I see. I'm not an AH flyer, so I didn't see anything too shocking in the stall speeds.

Sable
352nd FG

Hooligan · « **Reply #11 on:** March 02, 2001, 11:15:00 AM »

F4u I think the answer to the P-47 weight being a bit low is that it was loaded with 305 gallons instead of 370 gallons of fuel.

From the tables in AHT on pages 281 and 285 I see a D-27 to D-40 should develop 2600HP at 64" manifold pressure. Missing the 65 gallons in the Auxilary Main Fuel tank, it would weigh 14,021 lbs. It seems the 47 in the test you found was one of these.

Hooligan

Zigrat · « **Reply #12 on:** March 02, 2001, 11:46:00 AM »

65 gallons of fuel != 15 mph speed reduction

F4UDOA · « **Reply #13 on:** March 02, 2001, 01:33:00 PM »

CC Hooligan,

That was one fast Jug.

Zigrat,

I thing that extra 65 gallons of fuel was carried in an inflatable rubber raft dragging behing the A/C

Widewing · « **Reply #14 on:** March 02, 2001, 02:15:00 PM »

Quote

Originally posted by Hooligan:
F4u I think the answer to the P-47 weight being a bit low is that it was loaded with 305 gallons instead of 370 gallons of fuel.

305 gallons in the maximum internal capacity for all Jugs prior to the P-47D-25-RE.

Fuel capacity is another strong clue pointing to Vought testing an older razorback D model re-engined with a later model, uprated engine.

My regards,

Widewing