Author Topic: WWII myths & realities (Read 480 times)

Bodhi · « **Reply #15 on:** February 23, 2002, 12:51:42 PM »

Gentlemen,

As the project head for a current P-38 restoration, I can give some bearing on the validity that the Allison powered aircraft are superior to the Merlins at lower altitudes. I have worked on a multitude of various WW2 aircraft from the B-25 through to FW-190, and during this time I have on numerous occasions found that supplied data from both the military and other "reputable" sources to be in the wrong.

Given my current vocation, it goes without saying that I speak with quite a few veterans both in pilots and crewman, as well as maintenance personel. As for 38 pilots, the common statement I get from them is that they prefererred the Lightning to the Mustang below 15000 ft, and above that would prefer to have a Mustang, as the Merlin is better matched to it's supercharger than is the Allison / GE combination. The reasoning behind that is supported by the USAAF supplying early aircraft designers with both the power plants, superchargers, and components that were to be used to ensure commonality of spares.

Another interesting fact I have found is that bottomline, the Packard built Merlin is more sought after than the British built RollsRoyce Merlin. Reasoning being in both reliability and better craftsmanship.

So, friends, I caution you to be open to what those who worked on the equipment, and flew it say, as theyu really truly know how those aircraft perform.

HoHun · « **Reply #16 on:** February 23, 2002, 01:47:06 PM »

Hi Bodhi,

>As the project head for a current P-38 restoration, I can give some bearing on the validity that the Allison powered aircraft are superior to the Merlins at lower altitudes.

The V-1650-3 engined P-51B tested by the US Navy achieved speeds virtually identical to those of the Allison F21R engined Mustang I tested by the RAF up to the latters full pressure altitude of 4000 ft, and much higher speeds above that. The same Mustang I with an F3R Allison was decidedly inferior even at low altitude.

Have a look at the RAF report on the Mustang I:

http://www.fourthfightergroup.com/eagles/ap222.html

Regards,

Henning (HoHun)

Widewing · « **Reply #17 on:** February 24, 2002, 02:52:46 AM »

A couple of points:

Dutch Kindelberger had a handshake agreement with the Brits to produce the NA-73 prototype 120 days after the design was approved. Moreover, if performance was not measurably superior to the P-40, NA would be in default on the contract and not get paid for their cash outlay. Lee Atwood was present at all meetings with the Brits and stated that this was the understanding.

Now, as to the USAAC's interest in the P-51. There wasn't any interest. You refer to 150 aircraft being ordered. Not until the Lend Lease act was passed, did the Air Corps order the fighter. All were purchased for transfer to the RAF, and only two (the 2nd and 10th off the line) were to be retained for testing. After Dec. 7th, the Air Corps decided to retain an additional 56 of the fighters. Yet, no orders were placed by the Air Corps until well into 1942.

It was standard procedure to request that one or more aircraft be provided to the Langley test center for evaluation. The fact remains that the USAAC did not order the P-51 for their use despite glowing flight test reports from Langley. It is now accepted that Curtiss did a lot of arm twisting in an effort to delay P-51 procurement. Evidently, they were successful to a degree.

Escorting Bombers: Despite what many perceive, American heavy bombers were escorted whenever possible. Indeed, the first B-17 raid into France was escorted by British and American piloted Spitfires. Likewise, Eaker used the P-47s to escort the heavies to the limit of their range (the escorts). Those P-38s that deployed to Britain in 1942/43 had flown only a handful of sweeps before being transferred to North Africa. After the debacles of the two Schweinfurt missions, two P-38 Groups (20th and 55th) were rushed to England to provide escort for deep penetrations. However, virtually no theater training was provided, and the two Groups went active long before they should have, due to the political pressure being applied to 8th Air Force. Doolittle did not replace Eaker until January of 1944. By then, the P-51 and P-38 had already been flying escort for some three months. What Doolittle did was allow the escort to range out ahead of the bombers, discontinuing Eaker's policy of "close escort".

My regards,

Widewing

Wilbus · « **Reply #18 on:** February 24, 2002, 07:44:51 AM »

Bring it on...

oboe · « **Reply #19 on:** February 24, 2002, 05:58:19 PM »

Fantastic thread, guys!

I wasn't sure the AH community had this in it. Thanks for restoring my confidence!

MiloMorai · « **Reply #20 on:** February 24, 2002, 07:02:10 PM »

An additional note:
the Ford of England Merlins were better than the Merlins produced by Rolls-Royce.

It is my understanding that the XP-51 (41-038, -039) sat around at Wright(-Patterson) Field for several months before being tested (gun trials) in late 1941 and that was for the USN/RAF not the USAAF.

K West · « **Reply #21 on:** February 25, 2002, 07:56:18 AM »

IMO I can only echo others (Mr. Brody as well as Widewings comments in the past) have said in that what the Curtis co. and the WPB head (forget his name at moment. Big 'GM' guy) did to promote thier "pet" products at the expense of other proven, war winning developments was almost (was!) criminal.

Westy

lazs2 · « **Reply #22 on:** February 25, 2002, 08:49:03 AM »

according to AHT.. the early allison Mustangs would do about 390 at altitude and 335 on the deck. The allison mustangs were lighter and so.. rturned better. they would make great arena planes.
lazs

Hooligan · « **Reply #23 on:** February 25, 2002, 11:24:15 AM »

An interesting technical thread on the Allison engined mustangs can be found at: http://agw.warbirdsiii.com/agw//Forum3/HTML/026455.html

Hooligan

lazs2 · « **Reply #24 on:** February 26, 2002, 09:51:23 AM »

the allison mustangs were single speed single stage superchargers. they worked very well at low to medium alts with some models doing as high as 360-380 on the deck and about 400 at alt. They would be very fomidable arena planes. Much lighter and more nimble than merlin mustangs. They had a fantastic K/D ratio against LW planes but then... who didn't?

Glad to se WB finally seen the light and put em in the game. Real cure for the "allied vs axis" dead zone that is '42 FW days.
lazs

F4UDOA · « **Reply #25 on:** February 28, 2002, 03:06:03 PM »

Hurry up and get to the F4U stuff!!

funkedup · « **Reply #26 on:** February 28, 2002, 04:28:33 PM »

Niklas, I don't have the report but here are the particulars:

Report: NA-5798
Title: "Flight Test Performance for the P-51B-1
Date: January, 1944
Test Weight: 8,460 lbs
High Speed: 453 mph true airspeed at 28,800 feet at 67" HG and 1298 HP,
war emergency power, high blower, critical altitude.

I think America's Hundred Thousand has references to the tests in the 440 mph range for P-51B and P-51D. I'll try to get my copy out of storage and find the report numbers.

midnight Target · « **Reply #27 on:** February 28, 2002, 05:35:24 PM »

Question for Bohdi:

1st are you Bodi from AW? if so, hey this is .

2nd I read somewhere and I'm too lazy to dig it up again, that there were a relatively small number of P-51's manufactured in Australia. Additionally these seemed to be a large percentage of the surviving planes after the war and are sought after by restorers and collectors due to their craftsmanship. Not because the Aussies were better manufacturers, but because they took more time to build them and had less pressure on production rates. Have you heard the same?