Placing the Bell P39 Aircobra.

[Kutscha]

Originally Posted by tcolvin

Don't agree. The P-39 was superior to the Typhoon, Spitfire and P51 because although all their engines were liquid cooled, that of the P-39 was protected from ground fire. And protection of the aircraft's vitals from ground fire was the sine qua non of a CAS spec.

And was there any reason why the P-39's 20-mm low-velocity cannon could not have been replaced with a high-velocity cannon to make it suitable for tank-busting?

What was this protection on the P-39? Certainly you don't mean the thin aluminum fuselage skinning.

What cannon would that be?

[Graham Boak]

The Hurricane Mk.IV carried armour around the engine, radiator and cockpit. If this was not "meaningful" in comparison with the lack of same on the Mk.IId, then I suggest the difference is semantic not real.

Thanks for the Shores' reference, I shall look it up.

I would agree that the discussion seems to have moved away from its original intention, at least as I saw it. We are not discussing the real P-39 but some imaginary idealised version that might have embarrassed even Larry Bell.

[tcolvin]

Originally Posted by Graham Boak

The Hurricane Mk.IV carried armour around the engine, radiator and cockpit. If this was not "meaningful" in comparison with the lack of same on the Mk.IId, then I suggest the difference is semantic not real.

Thanks for the Shores' reference, I shall look it up.

I would agree that the discussion seems to have moved away from its original intention, at least as I saw it. We are not discussing the real P-39 but some imaginary idealised version that might have embarrassed even Larry Bell.

Janes' gives a weight for the extra armour on the Hurricane IV as 350 lbs. The 8-mm seat back must have been responsible for most of that. Compare the weight of armour on the IL-2 at 2,092 lbs; the Ju87G-1 at 1,540 lbs; and the Hs129B at 2,370 lbs. Shores doesn't think the Hurricane IV's extra armour is even worth a mention, writing only of its 'universal wing'. I wonder if you are pulling my leg.

We are discussing a P-39 design that was inherently superior for CAS than the Typhoon, and given a tiny bit of good will on the part of the RAF could have been made into a good CAS machine.

[tcolvin]

Originally Posted by Kutscha

What was this protection on the P-39? Certainly you don't mean the thin aluminum fuselage skinning.

What cannon would that be?

No, I don't mean the duraliminium skin. I mean the armoured bulkhead referred to by Shores below, and I believe there was armour protection to the oil cooler, but here I am out of my depth. I am referring to a design that could have been improved for CAS.
To quote Shores: "the engine was situated behind the pilot .... in this position it was considerably less vulnerable to ground fire than in the usual nose position, where instead armour plate had been installed.... It was its ability to double as an extremely effective ground attack aircraft which particularly endeared it to the Russians' hearts..."

How about the 40-mm fitted to the Hurricane IV?

[Kutscha]

With all respect to Mr Shore, the P-39's role was:

1. Protect ground units from enemy aircraft
2. Escort bombers
3. Suppress AAA in the area of bombers
4. Reconnaissance
5. Free hunt
6. Attack soft targets (i.e. troops, convoys, supply dumps, railroads, airfields, barges or other small naval craft)
7. Protect high-value friendly targets (i.e. bridges, amphibious landing forces, reserves, command and control, major cities, etc).

Gee, that 350lbs of armour on the Hurrie is less than what the P-39Q had, being 231lb. So what was the worth of the P-39s armour?

At least with an engine in front, some protection is given to the pilot, unlike the engine behind the pilot in the P-39.