I Flew the U-2
One of Lockheed’s former chief test pilots for high altitude reconnaissance describes the joys and terrors of the U-2.
- By Linda Shiner
- Air & Space magazine, March 2012
(Page 2 of 6)
No, I think the reason they went to a larger airplane was that they wanted more range and a larger payload—more capability. They wanted the same altitude, but we never got to the same altitude in the bigger airplane that we could in the little one. The smaller airplane was lighter and had a higher thrust-to-weight ratio, and it would get up there. We could get up to 74, 75,000.
How would it tell you that you couldn’t get any higher?
We’d have it at maximum EGT [exhaust gas temperature], so you were getting everything you could out of the engine and it didn’t have any more thrust to overcome the drag to give you what you needed to go higher. If you increased you angle of attack to generate more lift, it would generate more drag, and airspeed or Mach wouldn’t hold up.
You flew two aircraft that were structurally damaged, and you were advised to eject both times. Why did you keep flying?
We went back and pulled a lot of U-2Cs out of storage, and we had to verify that they had them all back together right. What happened on one of the airplanes was that on the hot section of the engine, they used a Teflon fairlead [a fitting mounted on a bracket to guide a cable]; that’s what control cables went through—these Teflon fairleads on the inside of the fuselage near the hot section of the engine. They had small holes, just so that the control cables could slide back and forth.
It’s interesting that these sophisticated airplanes had manual control with cables.
Oh yeah, the U-2, both the little one and the big one, did not have boosted flight controls. It was all pushrods, bell cranks, and pulleys and cables. We did not have boosted ailerons in either airplane. That’s why it had a yoke in it rather than a stick—to provide you with the leverage that you needed to move the control surfaces.
Why were there no hydraulics for boost?
To keep it light. The lighter it was the higher it would go. Every pound that the airplane weighed was a foot of altitude that you lost, so you wanted to keep it as light as you possibly could to get it as high as you could. When they added a new system, a new camera, a new radar that weighed ‘x’ pounds, that was altitude that you were going to give up.
And you’d have to fly that new camera or system to find out what impact it had on the altitude.
But back to the fairleads holding the control cables in place.
They used Teflon. But someone mistakenly selected nylon. Well, I went smoking off and the hot section of the engine melted the fairleads, and when I got to altitude and it was really cold, the fairlead that had melted congealed, and it had congealed around the control cable. And so I had trouble with it during the flight, and I couldn’t understand why it wasn’t maintaining climb schedule, and why I was having so much difficulty with it. At one point, the autopilot just couldn’t deal with it and it got real slow, and I attempted a programmed turn, and it stalled out. The airplane flipped over on its back, and I laid into the ailerons to keep it rolling because I didn’t want to wind up upside down. I got it right side up, and …
This is all happening in a matter of seconds, right?
Oh yeah. In five seconds or less. I was at about 60,000 feet when this happened. And I got it wings level, and it was heading downhill, so I pulled the throttle back and threw everything out—the gear out, the speed brakes out, flaps raised to the gust position—I was going straight down, but I managed to get it out of the dive, and recovered. I cleaned the configuration up, added power, and flew it back up to altitude not knowing what was going on. Then I took it back home, and I realized when I got down lower and tried to hand fly the airplane that I didn’t have any elevator control. And so I was just barely able to keep it straight and level, descending very slowly and finally made an approach to a landing and didn’t like it, so added power, and the airplane climbed back out, and then I came back around and tried it again, and my boss told me I oughta seriously consider jumping out of it because the airplanes were so fragile. They built them so light that they didn’t sustain damage very well when you impacted the ground. He thought I should jump out, but I had never ejected and I really wasn’t seriously considering that.
That’s a good record to preserve, never having ejected.
[laughter] I got through all of it without ever having to eject. When I got close to the runway, I pushed very hard on the rudder pedals and pulled very hard on the yoke, and it snapped the fairlead off its fitting, and all of the sudden, I had all of the elevator authority that I needed. The tail went down and the nose went up and it stalled and plunked on the runway, and that was it. When they got in it and found out what was going on, they had to go back and re-examine all of the airplanes that had gone through remanufacture and make sure that we didn’t have any more of those.
What about the second time you were told to eject?
Something was wrong with the lower Q-bay [where the camera was installed] hatch. One of the crew chiefs had failed to notice that the lower Q-bay hatch had not been properly locked on one side. So when I went to altitude and the Q-bay pressurized, the hatch blew partially open. Then I lost all the pressurization in the airplane, and the pressure suit squeezed me down tight. I was at altitude and trying to come down. And one of the procedures for descending was to lower the landing gear to increase the drag, so I put the gear handle down and kept waiting for the indication that the gear was down and locked, and nothing happened.
So I looked through the viewsight on the airplane at the landing gear to see what was going on, and there I saw that the Q-bay hatch in the partially open position was blocking the landing gear. It wouldn’t let it go down. So that’s when the guys on the ground said I better get out. The Q-bay hatch was part of the structure and necessary to maintaining the structural integrity, so a belly landing would probably have been disastrous. But I said, well, we got a lot of fuel here, let’s see what we can do. So I got it down to 15,000, 12,000 feet, and put all the G on the airplane that was permissible and went as fast as I could, and got that Q-bay hatch to flutter. While it was fluttering and the airplane is shaking and bouncing around. But every time it would flutter a little bit open, the gear would go down a half an inch or so. Eventually, by continuing the maximum G and maximum speed, getting the bay hatch to flutter, the gear eventually cleared the hatch, and went down into the down and locked position.
So I went home with a dangling Q bay hatch, but I landed the airplane, and I was pretty proud of both of those recoveries.
When you’re flying one airplane after another of the same type in a test program, can you tell any differences in the handling among them? Is one different from another?
They built so few of these airplanes that they were really considered to be hand made, and they all had idiosyncrasies. If one of these airplanes had its wing attached at a slightly different angle than the other, that caused the airplane to have lateral trim difficulties. It caused the airplane to have peculiar stall characteristics; it might roll off to the right or roll off to the left, or it wouldn’t stall straight through, and there was always something like that that you had to be conscious of.
And it was mainly by word of mouth that you learned of the difference between these airplanes. One pilot would tell you, well be careful of this. This plane’s going to do such and such.
Would that characteristic simply follow the airplane or would Lockheed try to remedy it?
Lockheed did everything it possibly could to eliminate those differences. They added stall strips eventually to the airplanes. They would alter the wing attachment points a very, very small amount to make them exactly the same. They would change the flap settings with minor adjustments to actuator rods, and they could lower or raise the flap maybe a fraction of a degree, and that would give you a little more, or a little less lift, depending on what was called for.
We had one that was really a nightmare, and they put a lot of Bondo on the leading edge of one wing to change the airfoil and the lift characteristics of the wing. And they eventually found out that the wing had been attached at a higher angle than it should have been, and they peeled all the Bondo off, and changed the attachment angle, and the airplane started flying about right.
The little airplanes were more susceptible to those idiosyncrasies than the big ones were. The big airplanes were a little more uniform in their construction than the little ones.