fredag 22 juni 2018

Some Notes on the Career of Charles Yeager

This entry takes a look at the career of American aviator Charles Yeager (1923-). The main source is "Yeager: An Autobiography" by Yeager himself and Leo Janos (New York: Bantam 1985). (A Swedish version of the post can be found here.)

We would like to say that Charles Elwood “Chuck” Yeager was courageous. Details aside, he represents courage in his roles as fighter pilot, test pilot and breaker of the sound barrier, a man being able to fly almost any plane after only brief instructions. The pinnacles of his career deserve some awe. You can’t just relativize it and say that “he was merely the right man in the right place, if he hadn’t done it someone else would have done it” – which, for its part, is an attitude ending up in a grey no man’s land where there is no bravery, no responsibility, no creativity, no zest, no pizazz, no glory – nothing.

Yeager was born in 1923 in West Virginia as a hillbilly; he uses the term himself in his memoirs, belonging to a stock of poor white mountain-dwelling people. But it was a happy childhood with time off spent in the woods, like hunting and fishing. In 1941 he enlisted in the air force, he started as a mechanic and became a pilot because of an opportunity that presented itself. It quickly became clear that he had an inborn talent for flying.

WWII was raging by this time and the pilot cadets were taught the basics in the plane Bell P-39, a single-seat fighter with nose wheel and the engine behind the cockpit; disliked by combat pilots it had been reduced to the role of trainer aircraft. Yeager for his part liked the plane but he knew the chant (technically a limerick):
Don’t give me a P-39
with an engine that's mounted behind.
It'll tumble and roll,
and dig a big hole –
don't give me a P-39.
When the training was completed Yeager was stationed in England as Mustang pilot with the 9th Tactical Air Command. The year was 1944 and the task was to escort bombers on raids over Germany, and thanks to the Mustang the fighter squadrons now could follow the bombers quite a long way – for previously, when only Spitfires were available, the fighter escorts had to leave and return home when reaching the German border because of shorter range for this aircraft type. The Mustang, however, had drop tanks assuring a longer range – and it had four to six machine guns and a sleek design, a fine example of “what looks good usually is good”.

Another American landmark plane now putting its mark on history was the Thunderbolt, a more ungainly design but this single-engine fighter was better than the Mustang in the attack and ground support role. For instance, in the battle environment the radial engine of the Thunderbolt could sustain machine gun fire better than the Mustang inline engine.

Yeager’s WWII service over Europe was dramatic but we’ll bypass it here and move on to his postwar career, which began no less dramatically with him being a test pilot for the air force. It was an interesting time with jet planes coming of age and the implicit approaching of the mystic sound barrier – the very barrier that Yeager would be the first in the world to break through. It would be done in 1947 in the Bell X-1, a rocket plane designated for this.

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The speed of sound is approximately 1,000 km/h (= Mach 1). Already when reaching 800 km/h, for example with a piston engine aircraft in a dive, it was noticed how the plane started shaking and how the controls seemingly “froze,” they got stuck. This was due to pressure waves being formed at the speed of sound, shock waves hitting rudder and stabilizer making the plane uncontrollable; many had crashed in these circumstances. For example, the Brits at the time were flying their tailless de Havilland DH 108 very close to “sound barrier velocities” – but – the three extant DH 108 prototypes eventually crashed, one after the other. Due to it having no tail, like a Me 163...? Due to the magical qualities of “the sound barrier”...?

The signs were ominous. It was thought by some that the sound barrier was very tangible, a solid wall that all planes slammed into when they approached 1,000 km/h.

The American company Bell tried to approach the problem of supersonic speed with the system Bell X-1, a rocket plane carried by a B-29 bomber taking it up to cruise altitude, 7,500 m. When released from the mother ship, the X-1 pilot would ignite the plane’s four rockets and attempt at Mach 1 in a climb, not a dive. Also, the whole stabilizer could be tilted, operated with a servo, avoiding the controls to be stuck when the pressure waves hit.

This, with Yeager at the controls, did it. It took many flights, many briefings and de-briefings to get to the heart of the problem (like actually using the tilting stabilizer), but they did it. “The best men will have the best machines” as Jünger once said. It was state-of-the-art technology and timeless bravery in cooperation; like, at one stage in the program Yeager had the feeling that he really would make it, that the sound barrier was a myth, and this “willpower-and-vision of the hero” is crucial to get things done in this world. This is material in writing history. You can’t sit in a lab (or an HQ, or a café) and plan success – no, you have to “get up and go” too, tangibly test the system in real life.

Yeager’s historical Mach 1 flight (actually Mach 1.07 = 1,126 km/h), the breaking of the sound barrier, was done at Muroc Air Force Base in California, on 14 October 1947.

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Yeager stayed on for some years as test pilot at Muroc, subsequently renamed Edwards, flying rocket planes and prototype jet aircraft, designs benefiting from the research data gained by the X-1 flight. For instance, he tested what would become the Century series, planes like F-100 Super Sabre, F-104 Starfighter and so on, titanium shimmering symbols of the jet age. F stands for “fighter” and as fighter pilot Yeager belonged to the US Air Force Tactical Command; there were also bombers in the Strategic Air Command and air defense of the US mainland in the Air National Guard. Next, after being a test pilot Yeager had to serve in the Air Force “cold war front line” for a while, being appointed squadron commander of a fighter group, based in Germany; it had planes of the type F-86 Sabre.

An event worthy of note is the Hungary Crisis of 1956 when all NATO airbases were on alert; Yeager’s group even loaded small atomic bombs on their planes and were prepared to fly towards the Soviet Union to bomb it if necessary. But the alert was called off and Yeager was glad of this, for instance, because of not having to go bomb Moscow and thus not having to walk back, the range of the F-86 being rather limited for missions like these. “Being forced to go home by foot when you’ve dropped an atomic bomb” may sound irrelevant but it’s details like these you as a human can relate to, while a thing like dropping an atomic bomb over the enemy is difficult to really imagine.

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In the mid 60s Yeager was commander of the air force astronaut school in the X-15-project, based at Edwards. This was a further development of X-1 the and other experimental planes of the 50s, this one intended as a spaceship that could land aerodynamically and not as a space capsule virtually fall right down after launch and orbit. The X-15 project was subsequently wound down precisely in favor of “capsules and rockets” but it did contribute to the later concept of the Space Shuttle. And the X-15 itself really did go out into space, like in 1963 reaching the altitude of 107,000 m, the legal limit for space being 100,000 m. The X-15 would be taken up to normal flight altitude by being carried under the belly of a B-52; then it was released, switching on its rocket engines, striving for 80-100,000 m altitude and then glide down.

Yeager never flew this plane, he technically never was out in space but he did make one attempt at an altitude record in a F-104 Starfighter used at this astronaut flight school, the aircraft being equipped with an extra rocket engine at the rear enabling the ship to reach 30,000 m altitude, an altitude were the laws of aerodynamics stopped being applicable and you had to have special nozzles with hydrogen peroxide mounted on the plane to operate it. Thus equipped the plane roughly reminded you of an X-15 which was the whole point, the astronauts getting used to near-space properties flying it.

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One day in 1963 Yeager got the urge to set a new altitude record for aircraft having started by its own engine. The Russians had the current record, 38,160 m – and Yeager took the specially treated F-104 and got going. In the film The Right Stuff (1983) this is well rendered, a last heroic feat, a “final shot at glory” by Yeager to end the movie, the drama having begun with his X-1 flight in 1947 and having the Mercury space program in between. Yeager also, of course, tells of this height record attempt in his memoirs – and, there we read that he took the plane up to 10,000 m with ordinary jet engine power – and then switching on the booster rocket to strive for 30,000.

However, in this critical phase he began to lose control, having neither the power to go further up nor the power to pitch down the nose to get a better angle of attack, this “pitching down” to be done with the peroxide nozzles. Because, the air around was still too dense for the trustors to have any effect, they only worked in vacuum or near-vacuum. And the ordinary rudder and stabilizer didn’t work in this thin air. So he lost control of the plane and went into a spin, being finally forced to emergency eject by the catapult seat, gliding by parachute to the ground.

Details aside it was a dangerous ascent, like Yeager when free off the plane being hit by the ejected seat itself and, also, having difficulties to breathe. All told, a heroic feat.

As for the purpose of pitching down the nose, it was intended at reducing the pitch angle just a little and then continue the ascent to 38,000 m and higher to beat the record. The problem with the weak nozzles began at 32,000 m height.

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Yeager also had a tour of duty in Vietnam, for instance flying fighter bombers and lecturing the pilots on how to do it. By this time he became Brigadier General, a rank he also had when he retired. He admits that he was a good pilot while also not so versed in the theoretical side of flying. The latter, however, is needed when being a test pilot – but – when Yeager was flying the X-1 he had one fine engineer ally, breaking down the facts and figures for him. Otherwise, Yeager had a fine technical instinct bordering on intuition.

We shall end this with a few anecdotes from the memoirs – Yeager.

Pro primo. When jet planes came of age Yeager went around demonstrating this new phenomenon to the public, flying a P-80 Shooting Star. He would then fool people that the plane was started like a blow torch, having to put something like a burning newspaper behind the exhaust. Someone in the audience was asked to do this, light a newspaper and hold it behind the plane, and then Yeager would sit in the cockpit and start it the usual, correct manner by switching on the engine, which no one saw.

Pro secondo. When Yeager was test pilot, his wife was so accustomed to him risking his life on the job flying jet prototypes, that when he one day came home pale and sweaty after work she thought that he had been in a car accident. She didn’t connect it to the flying activity but this time it was a near run thing, he had been close to crashing in an X-1 A rocket plane. 

Pro tertio. Yeager was familiar with Jackie Cochran, a woman record-holding pilot married to a millionaire. When the husband died, his last wish was to have his ashes scattered over the large property he had. Yeager and a pilot buddy decided to spread the ash by aircraft. Said and done and up in the air, where one was at the control and the other spread the dust through an open door – but then it was noticed that this was no good method, half of the ashes blew back into the plane because of backwash...

The Legacy of Space
Actionism (2017)
(In Swedish) Same Text as in the Above Post, in Swedish
The aircraft on the book covers is Northrop F-20 Tigershark, a prototype developed from Northrop F-5 Freedom Fighter.

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