Solving problems with the hood: about the history and design of the Bell P-39 Airacobra fighter

American transition aviation on high-speed monoplanes has led to an increase in the number of emergency landings. Among these was a tail-lifted landing, in which the aircraft touched the runway with its propeller. At best, this led to damage to the propellers, at worst - to the complete loss of the aircraft. It also came to the hood, when the plane literally did a "somersault", turning over through the nose.

This led to the fact that one of the American pilots, who experienced all the delights of the hood, submitted a report to the command, which contained an important proposal. It consisted in adding a front pillar to the aircraft. This strut would automatically prevent the aircraft from "pecking" with the nose and possible overturning through the front of it.

The first aircraft with a steerable front wheel instead of a rear wheel was created in 1932. True, such an aircraft originally carried the idea of ​​an aircraft that could move to the airfield and back along ordinary roads. But this plane was unsuccessful: when trying to take off from the field, the plane with its front wheel hit a hole (they say, into a gopher) and turned over.

The first fighter with a fully-fledged controllable front landing gear was the American Bell P-39 Airacobra by designer Robert Woods, who took into account the problems with the hood and the proposal of the American pilot.

About "Airacobra" and stories appearance, as well as the design of this fighter is told on the channel "True Life":

Comments

[Vladimir_2U]

At first, the nose landing gear was abandoned due to the Shimmy phenomenon, and then it started off.

[wow]

And then they simply installed a hydro-nitrogen damper on the rack.

[AlexVas44]

... with the front wheel hit a hole (they say, into a gopher) and turned over.

From the region - they wanted the best ... They fought with the hood on landing, and turned over during takeoff. It happens...

[Mountain shooter]

Once again it is confirmed - that the Russian is great, then the German (British, American) death ... From the point of view of the British, the unsuccessful plane fought well with the Germans in the east.

[Hiller]

Marshal A.I. Pokryshkin in his book "The Sky of War" - spoke very well about "Airacobra" !!!

[dmmyak40]

For some reason, the word "hood" hurts the ear. In Russian, the term "nosing" is adopted, if memory does not fail ...

[seregatara1969]

Doesn't fail. Rolled over through the engine hood

[geniy]

Again, general technical illiteracy. The author wrote in this article, as if the cause of the hood was a "lifted tail". But in fact, in order to stop the plane in those days when there was no reverse (and on combat aircraft it is not even now), the only way is to press the brakes on the main wheels. But when the brakes are pressed in, they immediately cause a moment to overturn through the nose. Therefore, the pilots could apply the brakes very carefully. But with the new high-speed aircraft, the landing speed became higher than that of the old biplanes and everyone wanted to press the brakes vigorously, and from this there were cases of overturning through the nose. By the way, Chkalov died from the hood, although not from braking, but crashed into the wires.
However, in 1945, a reversible propeller fighter appeared - it was a modification of the Yak-9. But jet fighters were already appearing and no one noticed this remarkable property.
But the reverse of the propeller could be a phenomenal salvation for aircraft - because the front pillar is an evil from the technical stupidity of aircraft designers. For example, there was such a wonderful BD-5 plane, a low-wing aircraft with a low wing, It created a powerful screen effect when landing and this led to many accidents - because it could not slow down. And in general, many high-profile aircraft are being created for fear of the screen effect. But the reverse of the propeller - the reverse thrust could ideally quickly decelerate any plane, from which the screen effect instantly disappears. By the way, the Aircobra has a low-plane scheme and it also has a powerful screen effect.

[geniy]

I'm a little curious - has anyone noticed wrong judgments in my post, or is it just some malevolent subject putting down cons?

[vadim dok]

"The front pillar is evil from the technical stupidity of avivconstructors!" And they still use this "stupidity"!

[geniy]

And they still use this "stupidity"!
Why are you surprised? The world is full of technical nonsense that has been used for centuries. For example, in the last century, a ram stem was widespread, which was installed on all ships - even very small mine boats and submarines during the Russo-Japanese War. Also, among the ships of the last century, the side inclined inward was widespread - this came from medieval merchant sailing ships from which the port tax was taken from the width of the deck and from this they tried to do it as soon as possible, although for the stability of the ship (especially a sailing ship) it is advisable to make the deck wide.
and on ships and tanks, guns were often placed in casemates - is it from a great mind or something?
And on the planes of the First and Second World War, they tried to place bombs inside the fuselage - they say that suspended from the outside, they create great resistance - but in fact, aircraft designers used this out of stupidity. Because it is not resistance at all, but the weight of the bombs itself, which requires an increase in the lift of the wing, and for this it is necessary to increase the angle of attack - and the resistance of the aircraft immediately increases. That is, the resistance of the aircraft increases the weight of the bombs - it makes no difference whether they are suspended inside the fuselage or outside.
But in our time, jet aircraft and bombs and missiles began to be suspended mainly from the outside - although the external suspension of ammunition greatly increases the aircraft's radar signature - its effective dispersion area.
And in the same way with ships: While it was not needed, then in the century before last they built all ships with sides inclined inward, but as soon as World War II began, they began to build ships with sides inclined outward. But this greatly increased the radar signature of the ships.
And in the same way with the nose landing and screen effect - instead of using reverse to destroy the screen effect, stupid aircraft designers used a nose landing gear, which inevitably has a shimmy.

[tolancop]

Quote: geniy

... And in the same way with the nose landing gear and screen effect - instead of using reverse to destroy the screen effect, stupid aircraft designers used a nose landing gear, which inevitably has a shimmy ...

The nose pillar, in addition to preventing bonding, allows the pilot to improve visibility during takeoff and jogging. Incl. aircraft designers are not stupid, but normal. The nose landing gear is a solution that came as a result of the development of aviation technology.

[starpur]

I read a slightly different story of the birth of "Cobra". The main idea is that the engine is located as close to the center of mass as possible. The pilot is moved forward, the view is gorgeous, the bow is packed with weapons. These pluses pulled the minuses with centering, and hence with a spin. The front leg is just a solution to the problem of movement on the ground, but not special. anti-hood. This is my opinion.