Should the US have used either the Vultee P66 or Curtis-Wright CW21?

[Marcel]

It was also use by the Dutch military to what extent I am not sure. I have a book with pictures of captured Dutch aircraft by the Japanese and there were a number of CW-22s.

Yup, it was mainly used as a trainer, but got thrown into action because the lack of fighters. It had one forward firing machinegun and one movable in the back. They were not very succesfull.

Generally the CW-22 was disliked by the KMIL. They liked the Buffallo better, being the better aircraft. But in the end, both aircraft were not very succesful, due to circumstances.

 

[davebender]

That's only an interim solution until the engine gets a proper supercharger. A better interim solution might be to install nitrous oxide injection.

 

[Civettone]

This post owes much to renrich. MHRIP

Seriously ?


Kris

 

[oldcrowcv63]

Seriously ?

Kris

Very serious Kris. I joined the forum with a post expressing much the same opinion as Davebender expressed in his post no. 31 above, blaming poor leadership for the FEAF disaster. renrich and I corresponded and he provided references that provided a more detailed and historically accurate perspective. We corresponded on other matters and our interaction was always enriching. I don't believe I am alone in benefiting from his presence in the forum.

 

[Shortround6]

That's only an interim solution until the engine gets a proper supercharger. A better interim solution might be to install nitrous oxide injection.

It is the solution used by a number of countries. I can't think of a single country that loaded it's planes down with as great a weight of guns and ammo as the United States in proportion to engine power.

A P-40E carried 409kg worth of guns and ammo, A Spitfire V or IX with Two 20mm and four .303s carried 295kg. A Typhoon with four 20mm cannon carried 426 KG. And these figures are not for the full gun installation.

Zero's, Oscars and even 109s carried nowhere near that weight at the beginning of the war. Even a 109 with a 20mm gun under each wing is carrying less wight of guns and ammo than a P-40E.

It is not until the Germans come up with the supercharger on the DB601E that they meet or exceed the capability of the Allison supercharger. The ONLY other superchargers to exceed the Allison by any significant amount are the Hooker improved superchargers on the Merlin XX and 45 series engines or the P W R-1830 TWO STAGE supercharger in the F4F.
The Two Stage Merlin is over a year away from going into service when the P-40-E goes into production.
Trying to provide nitrous oxide to fighter fields on a number of Pacific Islands, and Alaska and North Africa isn't a real good solution. The logistics of trying to supply the nitrous oxide are ridiculous.

 

[davebender]

More ridiculous then designing, producing and distributing a lightweight version of P-40E after December 1941?

 

[Shortround6]

Yep, A light weight P-40C can be done in the field (or at least at a depot) just change the cowl guns, fit new ammo boxes and yank the rear tank or replace with sheet metal tank.

Light weight P-40s were also known as the "L" model with Merlin and the first few hundred "N"s.

You could also make a lightweight "E" if you wanted by just replacing some or all of the .50 cal guns with .30 cal guns. and yanking the forward fuel tank. (expedient, just don't fill it.) Six .30s with 500rpg are almost 600lbs lighter than the six .50s with 235rpg.

Fitting nitrous oxide is a bit harder. You have to figure out the flow rate and have a regulator/injector. you have have a fuel circuit to add fuel for the nitrous oxide or the fuel mix will go lean and blow the engine up ( or at least hole pistons). You have to have the tanks and fit them to the airframe. And last but NOT least you need a supply of nitrous oxide.

Maybe the american system would be different, German system used compressed air at 135 AtA ( about 2000psi) to force the nitrous oxide to the engine from the tank. The German tanks would also loose their contents after filling in about 2 hot summer days due to evaporation.

From the Kurfurst site. Kurfürst - Kurz-Betriebsanleitung für Flugzeugführer und Bodenpersonal für GM 1-Anlagen in Bf 109 G.

duration of GM-1 flight time: (values ​​in brackets for 80 l filling) . 1 Start immediately after filling the system. Summer: 22 min (17) Winter: 22 min (17) 2 6 hours after filling summer: 19 min (15) Winter: 21 min (16) 3 12 hours after filling summer: 16 min (12) Winter: 19 min (15) 4 24 hours of filling summer: 11 min (9) Winter: 16 min (12) Since the container is not open in manual venting under pressure, is a refueling at any time.

For a squadron you are going to need thousands of liters of nitrous oxide per week and it needs special tanks to store it for any length of time. or some sort of nitrous oxide plant near the fighter fields.

I would say that there is a logistic problem and that it is NOT a short term, quick fix.

 

[tyrodtom]

You just don't add nitrous oxide and magically get horsepower. It takes engineering time and testing too.
If you redesign a aircraft, the results go out with the aircraft, but if it requires special fuels or additives, you got to distribute that too.

 

[davebender]

You don't just rip pieces off a combat aircraft to reduce weight either. There's some engineering and testing involved if you want the aircraft to fly properly.

Substituting .30cal wing guns for .50cal wing guns requires some sort of kit to mount the weapons and ammunition. Probably need to recalibrate gun sight too.

The only P-40E field fix I would trust would be to remove outer pair of .50cal MGs. That might help a little while still retaining adequate firepower.

 

[Shortround6]

Wing guns and even the cowl guns are pretty close to the CG. Certainly the change is minor compared to some of the suggestions made in these forums. British sometimes yanked .50s and replaced them with .303 Brownings on both P-40s and Buffaloes.
P-36s mounted one.50 and .30 in cowl and they were pretty much interchangeable left and right. Foreign Hawks got .30 cal guns (or equivalent). Not a whole lot of engineering needed. On the early P-40s the behind the seat tank was the "overload" tank and was supposed to be used first and be empty (or close to it) before combat or extreme maneuvers. Nor filling it or taking it out sure wouldn't affect things much if it was supposed to be empty anyway.
The P-40L and first Ns had the forward tank taken out as part of their "stripper" program. But then the "E" and later Hawks had the oil tank shifted from behind the seat to behind the engine and other internal equipment shifts.

Taking things out is a whole lot easier than sticking things in.

 

[Marcel]

Seriously ?


Kris

Kris, don't know if you read this: http://www.ww2aircraft.net/forum/news/richard-connally-renrich-memoriam-35623.html

 

[parsifal]

144 P-66s were ordered by the Swedish AF in early 1940. Deliveries were scheduled to begin from September 1941, but the US govt imposed an embargo at the last minute. China and the UK both expressed an interest in the type, and belatedly the US as well, so its stymied development was not due to any difficulties in attracting buyers.

After the embargo was imposed on the Swedes, anout 60 of the order were retained in the US for home defences. Losses to attritional causes were very high. ive read from a few sources that it had a tendency to roll over and then crash which suggests some sort of serious CG problem .

Others from that order were diverted to British and China. They spent months at Karachi, un-airworthy, and a large number were lost in transit accidents. Only 12 out of the original order ever made it to the Chinese air force front line formations, and as far as I'm aware, they achieved basically nothing.

Its safe to conclude that the P-66 ws not an outstanding success. After 1942, it was quietly dropped and quickly forgotten.

 

[buffnut453]

Its safe to conclude that the P-66 ws not an outstanding success. After 1942, it was quietly dropped and quickly forgotten.

Maybe so, but it was a pretty aeroplane!!!

 

[rinkol]

You just don't add nitrous oxide and magically get horsepower. It takes engineering time and testing too.
If you redesign a aircraft, the results go out with the aircraft, but if it requires special fuels or additives, you got to distribute that too.

The Germans had to do a lot of work to get it to a usable state. There were also the problems of added weight and increased vulnerability - if a tank containing NO2 under pressure was holed by a bullet, the tank would rupture with disastrous consequences. I recall that the Germans did come up with a less vulnerable form of construction for the tanks that involved wrapping them in wire.