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Men of the X-1
DeBeeler Goodlin Yeager
De Beeler was an aeronautical engineer for NACA, the predecessor to NASA. He helped design the X-1, which was the first airplane to break the sound barrier. Slick Goodlin was a test pilot for Bell Laboratories and made numerous flights in the X-1 before it was transferred to the military for the sound barrier attempt. In 1947, Chuck Yeager was a Captain with the United States Air Force assigned as a test pilot to the X-1 program. On October 14, 1947, he became the first person to fly faster than the speed of sound.


Designing the X-1

Powering | Controlling | Safety | Flying
Breaking the Sound Barrier | Reverberations

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Goodlin: I guess one could say that the X-1 was a bullet with wings on it. It was a very small aircraft. It was only 31 feet long and had a 28-foot The X-1 wingspan. However, it was built extremely rugged and it was possible to withstand enormous forces. The Bell X-1 was really designed the way it was because the designers at Bell examined a 50-caliber bullet flying at supersonic speed. And it was a very stable bullet aerodynamically speaking. And so they decided to build the X-1 in the form of a bullet with wings. And that is what the X-1 really turned out to be. It was only 31 feet long, it had a 28-foot wingspan. But the fuselage was shaped like a bullet.

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Beeler: The fuselage was shaped like a bullet, and the next thing we saw it had straight wings at about the mid-section and then the tail was elevated high, and there was a reason for all of this. The bullet shape was because of munitions research done many years before. The straight wing, we advocated that basically because of flight tests we did with a World War II fighter. The tail was high—we wanted that to wave in the wake from the turbulence from the wing. And then I remember one comment said, "Yeah, that looks great—how about the pilot?" And he didn't have a bubble canopy anymore. He couldn't see to the rear. And he had this high slope, aerodynamically it was perfect, but he was stuck behind that. And the next thing is well, how does he get out? Well, by this door. And no seat ejection. And then if he climbs out successfully, and there is a wing right behind him that could make hamburger out of him, and if that didn't do it, it would take up and hit in to the tail. So that was kind of a joking type of a thing. But aerodynamically, particularly if it was going to be rocket-powered, it looked the most aerodynamically clean configuration I think that we could come up with.

Powering the X-1
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Yeager: Basically the X-1 was a pure rocket. It burned liquid oxygen and a mixture of five parts alcohol to one part water. You know, we'd been fooling around with jets. Jets engines didn't have the thrust to push the airplane into the region of the speed of sound or beyond.

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Beeler: Personally I had some reservations about a rocket, when you see them operate. Because it's like a small explosion. But it would get you to the area of interest a heck of a lot quicker and I'm not sure that we knew that much about a jet engine—the time to get there and all the aerodynamic problems of getting the air to the engine. The rocket appeared to be the simplest.

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Goodlin: Well, I first operated the rocket engine in a special test cell at Goodlin posing outside X-1's door the Bell facility at Niagara Falls. And I must say that it was a very unnerving experience because the rocket engine made such an ungodly noise and shook the whole building to its foundations. And that was the most worrying thing about the entire X-1 program was the rocket engine. I wasn't worried about the air frame, but the rocket engine with its volatile fuels, which were liquid oxygen and ethyl alcohol, gave one some concern.

NOVA: What was your concern?

Goodlin: That we would have an explosion in the rocket engine.

Controlling the X-1
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Beeler: Well, when you reach the—near the speed of sound, you develop what we call a shock wave. And behind that shock we call it a dead water region. In other words anything that tried to operate behind the shock would become extremely ineffective—almost no effectiveness at all. And this occurred in some of the fighter airplanes when they dove at very high speeds from World War II, and we knew it would happen on the X-1 and it did. But we had a backup in which we had installed an adjustable tail plane in which we could use that, you might say, as an emergency device in which it would give the pilot longitudinal control. And it worked.

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Yeager sitting in cockpit of the X-1, with door off Yeager: When we got the airplane up to 94 percent of the speed of sound and I'm sitting out there and I decided to turn the airplane I pulled back on the control cock, nothing happened, the airplane just went the way it was headed. And I said, man, we've got a problem. So I raked the rockets off, and jettisoned the liquid oxygen and alcohol and came down and landed and we got the engineers together and we had a little heart to heart talk. I said, "We've got a problem—because the airplane may pitch up or pitch down. I've lost the ability to control it."

Safety and the X-1
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Goodlin: As a matter of fact I was unhappy about the X-1 from the escape potential because it was very badly designed from that standpoint. The entrance hatch was on the side directly in front of a very sharp wing. And I felt that if one had to bail out of the airplane in an emergency, if one didn't hit the wing, one would hit the horizontal tail surface, and therefore I thought it was a very dangerous airplane.

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Yeager: Colonel Boyd, you know, sort of evaluated everything and ended up calling me in and said, you know, if you get the X-1 program we... pay attention and fly safe and don't bust your fanny. And I said, "Yes sir." And that was about the end of it. And then about a month later, after I'd been assigned to the X-1 program he called me back in and said, "You know, we've got a problem." He said, "I wanted a pilot who had no dependents." I said, "Hey, Colonel Boyd," I said, "I, yeah, I'm married and I, I've got a little boy, and I, I think that makes me more careful." And that worked out. He said, "Well, OK, be careful."

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Goodlin: I can't imagine why they got to the point of building the airplane without having proper escape provisions. I don't know how that ever happened, but I was not involved in designing the airplane.

NOVA: Isn't that a sign that the, the project is being made more important than the lives of the pilots who are being asked to test it out?

Goodlin: Of course. But this happens all the time in the military-industrial complex.

NOVA: So did it make you feel almost like a pawn in the game?

Goodlin: Well, I think at that stage in my life I wasn't thinking about analyzing the military-industrial complex. Today I do. But at that time I was just a, a very eager adventurer, and I loved flying. And being involved in the hottest aviation project in the world causes one to overlook the basic fundamentals, such as pilot safety.

NOVA: What about the dangers in flying this plane?

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Yeager: That's immaterial. Duty above all else. See, if you have no control over the outcome of something, forget it. I've learned that in combat. You know, you know somebody's going to get killed, you just hope it isn't you. But you've got a mission to fly and you fly. And the same way with the X-1. When I was assigned to the X-1 and, and was flying it I gave no thought to the outcome of whether the airplane would blow up or something would happen to me. It wasn't my job to think about that. It was my job to do the flying.

Flying the X-1
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Goodlin: Well, it was a very exciting experience as you know. The X-1 was carried aloft in the bomb bay of a B-29. And the procedure of going down the ladder and crawling into the X-1 at 8,000 feet and then sealing the door and The B-29 parked on the runway with X-1 slung beneath it being carried still higher to 28,000 feet, it was rather exciting, you know. I had no apprehension about it because we had no rocket fuel on board. And so when we got to altitude and went through the normal procedure of countdown and here I was in a very tiny cockpit and it was very dark, and all of a sudden when the X-1 was released from the B-29 I was in bright sunlight and I could hear nothing, it was so silent. And it took my eyes awhile to become accustomed to the daylight. And of course as one was without any power it was necessary to immediately examine where our position was in relation to the airport because one had to always stay within the landing distance, or gliding distance of the lake bed—and at the same time put the aircraft through the maneuvers, stall tests and the stability and control tests. And it was all very exciting but it went off extremely well. And I landed on the lake bed without any difficulty.

It was a very delightful airplane to fly, as a matter of fact. It had the, the handling characteristics of a fighter plane. And it was very agile. I had no complaints about the flying qualities of the airplane at all. The serious points on the X-1 were the rocket engine and those escape provisions.

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The B-29 in flight, with the X-1 slung beneath it. Yeager: Since the airplane was liquid rocket powered it only had two and a half minutes of power under full thrust. And consequently we decided to drop it from a B-29 mother-ship to conserve fuel. And that's the way every flight, with the exception of one, was launched from a B-29 or a 35... at around 25,000 feet. After drop, clear of the B-29 you'd fire off one, two or three or four chambers of the rocket motor. They were not throttle-able. You could just select the chambers either on or off, and you ran it until it ran out of fuel. And then you dead sticked into, into Roger's Dry Lake.

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Goodlin: So then when the drop took place, one would sort of count to ten and hit the rocket engine control. And we had four positions on the rocket engine for each rocket chamber. And to fire up one rocket. And of course the first time I did it, it was like being hit in the back with a lead boot. And the aircraft accelerated very, very rapidly. And of course as one increased the thrust by adding more rocket positions—actuating more rocket positions—well, the aircraft could go very fast indeed, and quickly leave behind the B-29 and the chase plane. And of course the first time I did that, why shortly after I accelerated, the fire warning light came on. And that caused the adrenaline to flow. And so I immediately shut off the rocket motor and called Dick Frost on the radio, who was flying the chase plane, and asked him if he could see any fire—that my fire warning light had come on. And of course he was way behind me and said he couldn't see any evidence of fire. But after I had slowed down, why he could pull up behind me and he could still see no evidence of fire, but my fire warning light was still on. So I dumped the rest of the fuel and went back to the landing area and set the airplane down. And sure enough we had sustained a rather serious fire in the engine compartment.

NOVA: When the fire warning light came on, describe your feelings.

Goodlin: Well, it's a rather hopeless feeling because one can't see behind from the X-1 cockpit. And so one can only assume the worst, that there's a fire raging there. And so all I could do was wait until Frost could pull up behind and tell me that there was no, absolutely no fire visible. But obviously one thinks all sorts of things, and of course I was concerned because of the lack of escape provisions in the airplane.

Breaking the Sound Barrier
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Yeager and Ridley, posing in front of X-1 as it's slung under parked B-29 Yeager: The flight, October 14, fell on a Tuesday. And I think Glennis, my wife and I, were over at Pancho's having dinner, and we went horseback riding. I ended up breaking a couple of ribs when the horse hit a fence and tumbled. And when Monday come along, I got Jack Ridley and said, I've got a problem, I've got a couple of broken ribs, I can't—I don't think I can close the door with my right side, my right arm, and he, that's when he got the broomstick and I stuck it in with my left arm and closed it. And once we found that out, as far as getting into the airplane—it was very, oh, painful, because you have to bend up double to slide in. Once I got in it was no problem.

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Yeager: We didn't—we had no idea anything was going to happen. There was some indication on the previous Friday's flight that we had a very large error in our Mach meter. Otherwise we were indicating about 9.3, or .94 Mach number which was 94 percent of the speed of sound. There's some indication when NACA reduced the data from our instrumentation in the airplane that we're going a X-1 in flight lot faster than indicated. And there was some, a little bit of excitement that said, hell, we, it looks like we've, we've been up to about 99 percent of the speed of sound. And we still are in buffeting and the airplane is shaking quite a bit. You know, they weren't sure, because you, you're in an area where very little is known. They had no wind tunnel data, nothing, and everything was trial and error. And there was some indication that we had been going faster than we had thought. But we had no idea what was going to happen on the next flight. And when we got the airplane up to oh, about 96 percent of the speed of sound indicated, that was almost Mach 1. And when we went a little faster the Mach meter went off the scale. And ah, when it did all the buffeting smoothed out, because of the supersonic flow of the whole airplane. And even I knew we had gotten above the speed of sound. And I let it accelerate on out to about 1.06 or 1.07, seven percent above the speed of sound, and the airplane flew quite well. And I got some elevator effectiveness back, but not very much.

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Beeler: And then, The best I remember now, we knew the rocket was on, and we really didn't get anything back from Chuck. You'd have to look at the telemeter data if we did. But as far as us listening, the next thing is that Chuck says, I think he did make a remark on his longitudinal control, I forgot. But the next thing my Mach meter jumped. And then at that time we got a bang. And personally, I have to say, I didn't know anything about bangs. I didn't know anything about it. Someone may say they knew about it from gunshots and that sort of thing, but to people around there, we got a bang.

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Yeager: Your emotions on something like that—you're too busy staying on top of the dome regulators and watching the chamber pressures and doing everything you're supposed to. And you might say I was a little bit disappointed it didn't blow up. That's about the only way to say—hell, it's a piece of cake.

Reverberations
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Yeager: A lot of the news media were digging, you know, and I'm sure the intelligence people from the Soviet Union and the French and the British were all digging. Then after about seven months, you know, we satisfied their digging. We released the fact that we had flown faster than the speed of sound. That, you know, that satisfied their digging. What they didn't know was how we had done it.

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Beeler: When Chuck made that supersonic flight it opened up a big wide door and everybody could jump in with all these applications. And that was one—that probably is the biggest impact as far as the world economy—people in one world type of thing.

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Yeager posing by X-1, with parachute on Yeager: Obviously the reason we kept it classified was to keep the rest of the world from finding out about a flying tail that's necessary to control the airplane through the speed of sound. It resulted in a kill ratio of 10 to 1 between the F-86 and the MiG 15. That one simple thing, of putting a flying tail on the F-86, because we knew that it would dive to the region of the speed of sound, and it pitted it against the MiG 15 in Korea, in 1951, '52, and '53, and we had a kill ratio of 10 to one. And when I flew the MiG 15 over there for the first time I was amazed, because it was a good airplane, just like the Hawker-Hunter was or the MD-452, that Dassault built for the French air force, but it didn't have a flying tail on it.

Photos: (1,3) NOVA/WGBH Educational Foundation; (2) Aila Vainio; (4,6-11) AFFTC; (5) Chalmers H. "Slick" Goodlin.

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