There are days when I *really* love my job more than usual. Today was one of those days.

I happened to attend a meeting today and Robert Yahn was present (former U-2 pilot). At lunch, he mentioned that he's pretty sure that he's the only pilot to have rolled the U-2. An active duty U-2 pilot nodded in agreement.

His story:

The autopilot was in Mach-hold mode. Due to temp variations, the aircraft was climbing, and descending. He called this mach-surfing, not that unusual. But the phugoids became larger and larger due to the Fred Flintstone autopilot - PIO-like, so he disconnected the autopilot, recovered to straight and level and punched-On the autopilot again.

The mach-surfing returned and the phugoids became larger, then as it was about to push-over and began another descent, the autopilot disconnected. The airplane began to slowly roll to the right. He corrected with left aileron. The roll continued. More left aileron. It continued rolling right, and he had full left aileron deflection and a boot full of left rudder. It continued rolling - taking ~3 secs to roll to knife edge ... and having no more left aileron, and seeing North Korea like he'd never seen it before, he went full right with the aileron to complete the roll. He said it took ~1 second to roll the remaining 270 degrees and recover to straight and level.

The FDR confirmed his report. Root cause? The subsequent investigation and test flights confirmed that the this particular airframe was mis-rigged.

A few others at the table told their "most scared" aviation experiences. All I could muster was, "Well, there was that one year when I thought I might starve to death!"

Good Lord!

A little further U-2 history. In the late 1980's I was selected (did not volunteer) to be a demonstration pilot for the U-2. This was a new idea that the Commander of SAC thought would be good, that all airframes in SAC would have demonstration teams the same as the fighter world. The idea was that I was supposed to fly aerobatic maneuvers in the U-2 at airshows to demonstrate its flying capabilities. That the U-2 was only stressed for 2G's did not seem to faze too many people. I was more than a little bit skeptical.
As part of the preparation and research to see what the article was capable of doing I was sent down to Palmdale to see Ben Rich (took over from Kelly Johnson as head of the Skunkworks) and see if there was any data on what might be possible. Our preliminary idea was to go gust up on the flaps and dive to get max airspeed of 260 knots and pull up at 2 G's and at the top do a half roll (Immelman). Putting the nose down gains airspeed really fast and would probably tear itself apart if we tried to do a loop.
During my discussion with Mr. Rich he amazingly told me they had already done aerobatics in the U-2 as part of research test on carrying air to air missiles for defense against fighters. Art Petersen (no relation), a Lockheed test pilot did the tests. However these tests were in a C model, the original size U-2. It only had a wingspan of 80 feet versus the 104 feet of the R model I was going to fly. It handled like a sports car while the bigger R model was more like a Cadillac. The responsiveness of the R model is not good. Very slow roll rate and very heavy flight controls at high airspeeds (our flight controls are all cable, no hydraulics or boost available). I set up another date to come down and meet with the Lockheed test pilots and further discuss what had already been tested. The fact that at C model could do aerobatics did not mean an R model could safely do them.
Before I got to go down again, the demonstration B-52 at Fairchild AFB in Spokane, crashed while practicing its high performance maneuvers. There are videos available on Youtube showing the crash. Hit the parking lot of the Tanker squadrons and killed several folks on the ground, including a friend of mine.
Shortly after that, the entire SAC aircraft demonstration teams were cancelled and I did not have to do anything really stupid.

Steve,

Does Yahn's story square with squadron lore?

Doug,

The only one in the plane was Bob so there is no independent confirmation of what happened. We have datalink data on aircraft orientation but in a maneuver like that, the link would have been broken. Yahn soloed much later than me and I was out of the program when he was flying. I vaguely remember the story, as I was the Air Attaché at the Embassy in Seoul when he would have been flying in Korea. However I do not have any way of confirming or denying whether it happened as was remembered.

I will say this though, that the aircraft very rapidly builds up airspeed when the nose gets down. When we are at altitude, we are very close to our max mach. If we go over that speed, the air over the fuselage goes supersonic, moving the center of lift and causing the nose to go down more (wings level). If rolled at altitude one would have to be make sure the nose did not go below the horizon. I could see it happening if the roll was started with the nose very high above the horizon and the maneuver was much more like a barrel roll.

I "heard" that one could roll a Grumman American Trainer by doing that same thing.

Never known a U2 pilot to fabricate a story......and they have a good number of them. Unfortunately they probably cant tell us the best ones

Bob and I were lieutenants way back. He never told me this story, now I'll have to beat it out of him.

... And no alcohol was involved in the story telling. We were all stone cold sober.

He had a few other stories ... ask him about the U-2 windscreen defroster. He described it as another Fred Flintstone device.

If my count is correct, there were four other "green door" patch wearers present.

You're right Greg, we never knowingly tell a falsehood. However we have been known to leave out a few details.