Amazing WWII Aircraft...

[Keith]

I have always been interested in military aircraft, especially from WWII era when the most technical advances in flight were made, but I had never heard of this astonishing machine. Perhaps it is because the RAF (who ordered several hundred of them) quickly abandoned them as they did not have the performance ceiling they required in the European theatre. However, many thousand went to the USSR as part of Lease/Lend where they acquitted themselves very well and to the Far East where they were used by the USAF (in particular the Cactus Air Force) and the RAAF, where again, they acquitted themselves very well in the flying conditions prevalent in that particular theatre.

None remain in the UK but I believe there is a flying example in the US where they made for very efficient and quick low level pylon racers (Mustang beater), and Australia.

Technically revolutionary and perhaps the only example ever of this remarkable powertrain configuration, although jets took over the mantle in subsequent years.

Love the "car" cockpit doors!

 

[Keith]

One more "exploded" view...

 

[Randy V]

AKA P39 Airacobra... Et al..
https://en.m.wikipedia.org/wiki/Bell_P-39_Airacobra

 

[Rick Muck- Mark IV]

Built in my neck of the woods.

Pilots didn't like the "automotive" door and the driveshaft passing under the family jewels. There is a limerick about the AiraCobra something about "Oh please don't give me a P39....."etc.

I have aluminum scraps we use to fab small stuff that is leftover P39 materials that a friends father brought home form the Bell plant.

 

[Doug S.]

Geez...a "mid-engined" airplane design!!!

My dad flew some sort of plane in WWII in which the driveshaft coursed between his legs...I thought perhaps a P51, but if this was the only airplane designed with a drive-shaft through the cockpit then I am obviously "mistaken".

Incredibly complex engineering, visible only without the body panels.

Cheers!!!

Doug

 

[Keith]

Indeed. a mid engined model and perhaps the only one ever. The story of how the RAF ordered several hundred is quite intriguing according to Wikipedia: They selected the Airacobra on the basis of it's performance and operating ceiling based on Bell's prototype which was turbocharged. The subsequent models that arrived in the UK had no such turbo fitted and no armour plating! So they were seemingly promised a 400 mph plane but only received one capable of 350 mph (with additional armour plate fitted) and that only achievable at a relatively low level.

Still, the Russians were happy enough with it..

Fascinating design and a good performer out of the box. I wonder if the advent of jets forestalled any further development of the concept?

Not sure that a rotating shaft under the crown jewels would have been much of an issue but it certainly might have been if there was a UJ anywhere near!

 

[Doc Watson]

If I had to sit in it I would be a little concerned......

 

[Rick Muck- Mark IV]

The ditty is:

Don't give me a P-39.

The engine is mounted behind.

They'll tumble and spin and auger you in,

Don't give me a P-39.

 

[Rick Muck- Mark IV]

This is down the street..

Our Collection | Niagara Aerospace Museum

Video here: https://vimeo.com/9502614

 

[Keith]

That has to be an early photo of the 1st pic in thread..

 

[Jac Mac]

Case of what you don't know wont hurt you!, We have probably all driven a Front engine rear wheel drive car with the driveshaft 6" away merrily spinning at 7000rpm in top gear, the latest crop of 5/6 speed OD trans up the driveshaft rpm even further..

If I had to sit in it I would be a little concerned......

 

[Mark R]

Case of what you don't know wont hurt you!, We have probably all driven a Front engine rear wheel drive car with the driveshaft 6" away merrily spinning at 7000rpm in top gear, the latest crop of 5/6 speed OD trans up the driveshaft rpm even further..

Other than cars with a front engine/rear tranny like vets, where does a driveshaft spin anywhere near 7k rpm? And don't those cars have the shaft encased in a tube?

 

[Marcus]

Indeed. a mid engined model and perhaps the only one ever.

Oh no, Gefreiter Hardy :stunned:

https://en.wikipedia.org/wiki/Dornier_Do_335

 

[Ron Earp]

The Russians also liked the improved big brother, the KingCobra.

https://en.wikipedia.org/wiki/Bell_P-63_Kingcobra

and were heavily involved in its development.

It appears these aircraft were not heavily used for ground attack (in addition to other duties) as I had mistakenly been told or read.

In general, official Soviet histories played down the role of Lend-Lease supplied aircraft in favor of local designs, but it is known that the P-63 was a successful fighter aircraft in Soviet service. A common Western misconception is that the Bell fighters were used as ground attack aircraft.

One of the enduring myths regarding the P-39/P-63 in Soviet use is that because of its armament, in particular the 37mm nose cannon, it excelled as a ground-attack aircraft, even a 'tank buster'. In translating and preparing this manuscript for publication, I have had the opportunity to peruse several Russian-language sources. Mentions of the employment of this aircraft in the ground-attack role are so rare in these sources as to be exceptional ... The 'tank buster' myth has its roots in the misunderstanding of the general wartime role of the Red Air Force and in the imprecise translation of specific Russian-Language terms that describe this role. The specific Russian-Language term most often used to describe the mission and role of the Airacobra-equipped Red Air Force fighter units, in this manuscript and other Russian-language sources , is prikrytiye sukhoputnykh voysk [coverage of ground forces]... Frequent misunderstanding in this country as to the combat role of the P-39 in Soviet use is based in part on imprecise translation of the term prikrytiye sukhoputnykh voysk to 'ground support'. The latter term as it is understood by many Western military historians and readers, suggests the attacking of ground targets in support of ground troops, also called 'close air support'. Did a Soviet Airacobra pilot ever strafe a German tank? Undoubtedly. But this was never a primary mission or strong suit for this aircraft.

— Soviet Army Colonel Dmitriy Loza​

 

[Rick Muck- Mark IV]

Well the Russkies also liked to use the prop to "de-tail" Nazi aircraft when they ran out of ammo!

 

[Ron Earp]

That sounds like something that happened very seldom and was blown out of proportion. Using the prop to destroy another aircraft greatly reduces the chances of the pilot flying another day or the aircraft being used again, neither of which are conducive to continued air operations by the Russians.

 

[Jac Mac]

Other than cars with a front engine/rear tranny like vets, where does a driveshaft spin anywhere near 7k rpm? And don't those cars have the shaft encased in a tube?

Most English/European stuff from the 60's thru 80's was open driveshaft, my road going Anglia with 1500cc pushrod would pull over 7k in top anytime I felt like doing so. Mustang Boss 302 would haul 7300 in top. Latest Mustang / Camaro 6 speed manual with 0.63 or 0.50 OD running @ 4400/3500 engine RPM on those ratios respectively will have a driveshaft at ~7k.... all of these are open driveshaft.

Most WW2 V12's had max engine RPM in range of 3000/3500. so P-39 / P-63 is about the same as road going car at highway speeds to the road going car.

I was suggesting that most of us on here might have dabbled in a bit of fast road driving at some stage, might have been wrong there, perhaps many are just a bunch of frustrated law abiding highway cruisers!!

 

[Rich McD]

As I understand it, the P-39 was never "owned" by American fighter pilots because of its nasty stall/spin characteristics. Moving the heaviest parts to the center of inertia caused it to rapidly enter a spin when departed controlled flight, which degraded to a flat spin in short order. Think of a mid-engine car hanging in there until loss of traction and then bad things happen very rapidly.

No fighter pilot is worth his salt if he is not operating his aircraft at the limit as he will be beaten by the other guy who is. If he faces the prospect of permanently losing control of the aircraft by momentarily exceeding its limits, he cannot enter a fight with the confidence to win.

There is an extremely low probability of surviving bailing out of an aircraft in a flat spin. Think of riding a spinning metal Frisbee down vertically and attempting to jump off, falling at the same rate initially as it is, without being hit by large spinning metal parts. Hard to fall in love with a beast with those tendencies. Pretty aircraft to look at though in a fly by at the airshow.

The Russians took them as they were better than what they had in a terribly depleted inventory of fighter aircraft. Desperation drove them to accept such a gift.

 

[Keith]

According to Wiki: "It was determined the P39's (flat) spin could only be induced if the aircraft was improperly loaded, with no ammunition in the front compartment. The flight manual noted a need to ballast the front ammunition compartment with the appropriate weight of shell casings to achieve a reasonable center of gravity."

Also worthy of note to other concerns highlighted in an earlier post that there was not one single recorded failure of the prop shaft..

 

[Scott Calabro]

According to Wiki: "It was determined the P39's (flat) spin could only be induced if the aircraft was improperly loaded, with no ammunition in the front compartment. The flight manual noted a need to ballast the front ammunition compartment with the appropriate weight of shell casings to achieve a reasonable center of gravity."

Also worthy of note to other concerns highlighted in an earlier post that there was not one single recorded failure of the prop shaft..

The Aircobra had an additional propeller reduction gearbox mounted in the nose, taking some of the prop torque load off the driveshaft. This also allowed a gun to fire straight down the aircraft's longitudinal axis, through the prop hub.

I'd rather be flying a "Jug" or F4U though :thumbsup: as liquid cooled engines are a bit fragile in a gunfight!