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
USAF
Marine Corps Reserve Major General Kenneth Weir (ret.) flew U-2s as a Lockheed test pilot between 1966 and 1993. A Marine aviator and graduate of the U.S. Naval Test Pilot School and the U.S. Air Force Aerospace Research Pilot School, Weir accumulated more than 19,500 hours in more than 200 types and models of aircraft.
Air & Space: Once an airplane has been flying in service, as the U-2 had been when you started at Lockheed in 1966, what is the test pilot’s job at that point?
Ken Weir: The airplane’s flight envelope had been expanded by the first pilots who flew the it. After it goes operational, most of the work done by the test pilots is developing electronic systems for the airplane—the sensors, the photographic equipment, the ELINT [Electronic Signals Intelligence] systems, modifications to the autopilots, flight control systems, and things of that sort.
The TR-1 was a production re-start of the U-2R with the addition of “Super Pods” on the wings to accommodate extensive new airborne sensor systems. The Super Pods caused unforeseen structural dynamics at high Mach numbers at very high altitudes that had to be resolved. The U-2S airplane was the re-engining of all of the big U-2s with a new General Electric F118 turbofan engine. The initial flights were flown without any airstart capability until the incorporation of a hydrazine starter.
We verified the high-altitude performance of cameras that were to be used in satellites for reconnaissance. The manufacturer would develop the cameras, then we’d carry them as high as we could get them and check them out before they went into the satellite programs. Initially, the pilots weren’t allowed to look at the pictures; they kept that compartmentalized, and we were shown only some of the tracker camera film. That was mostly unclassified. The pictures from the higher resolution cameras, they kept covert. We didn’t get to enjoy what we called “our take.”
So the pilots didn’t get to see the pictures they were taking.
I’ve seen more of those pictures now in history books than I saw in the program. We did have a viewsight: There was a periscope that poked out of the bottom of the airplane, and you could get a look at where you were, so you could kind of imagine what the cameras or infrared or side-looking radars were getting.
What was it like flying missions that you couldn’t tell anybody about?
Everybody was guessing, and you couldn’t tell them, so you just let em keep on guessing. And that made it more intriguing.
You flew both the earlier, shorter-winged U-2 and the more modern variant with the very long, 105-foot wingspan.
I flew the little one and the big one. They modified the A model to put the bigger engine in it, and that was the C, the hot rod. That was a really fun airplane to fly. The Cs had a higher rate of climb; their thrust-to-weight ratio was a lot better.
They were a lot dicier airplane to fly because of the airfoil. In 1968, they built the big airplanes, and they had a much larger wing area and a different airfoil. They were a lot easier to handle at altitude; they had roll spoilers to go along with lift spoilers.
The G model was also a small airplane. That was the U-2C that was modified for carrier operations. They put a little different camber on the leading edge of the wing, and put lift spoilers on it, and a tailhook of course. And with the big engine—the J-75 non afterburning engine—it would just leap up. It would rocket to altitude. It was a fun airplane to fly also.
What was the challenge of flying the smaller airplane?
When the littler airplane got up to altitude, the margin between the climb speed and the critical Mach number and stall became very, very minor, and we were looking at plus or minus two-and-a-half knots at one particular point in the climb between the climb schedule and critical Mach and stall speed so that’s very very small. When we got the bigger airplanes, we got up to plus or minus seven-and-a-half knots of margin.
But we were saddled with trying to maintain that climb schedule for long, long periods of time, so we would never go to altitude without an autopilot. You engaged the autopilot as you were climbing out, and then you got into the climb-Mach schedule, and you engaged “Mach hold,”; you had a small Mach trim wheel so you could tweak it just a little—more Mach or less Mach. And it maintained that climb schedule. It was almost impossible to “hand-fly” it—disengage the autopilot and try and fly it up through there with the yoke.
When Francis Gary Powers (we called him “Frank”) got shot down, he was having trouble with the autopilot, and he had to descend to a lower altitude to hand fly it, and that’s when the surface-to-air missiles were able to get him.
How did it help to descend?
At lower altitudes, the airplane was more stable and there was more margin between the stall buffet and critical Mach number buffet. During the cruise phase of the mission, as you burned off fuel and the aircraft got lighter, you had a little more margin even as it gained more altitude. The envelope expanded as you got higher and higher and lighter and lighter. Then you got more margin between the Mach buffet and stall buffet. If you encountered buffet, the first thing you did was go faster. You’d assume it was stall buffet, and you wanted to go faster because if you guessed wrong and slowed down, then it would stall and quit flying altogether. It would flip over on its back, and that’s how we lost a lot of the airplanes. It stalled at altitude, it would head straight down, and the tail would snap off.
Is that why the change was made to the longer wing?
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Comments (8)
Major General Weir got it wrong in regards to the May 1 shoot down. Below are exerpts from an article I wrote in February 2012 for The Moscow Times.
50th Anniversary of Spy Exchange
By Francis Gary Powers, Jr.
February 10, 2012 marks the 50th anniv. of the spy exchange between U-2 pilot Francis Gary Powers and Soviet spy Rudolph Abel.
...
During the time the pilot was incarcerated in the Soviet Union ... US government officials thought that the most likely cause for his capture was a flame out which caused the U-2 to descend to a lower altitude where it was then hit by a Soviet MiG or missile. This is what many in the CIA and US government thought and advocated to the press until the pilot was returned home, debriefed, and able to share his experience with his superiors.
When Powers returned home he was extensively debriefed and able to confirm that there was no flame out or sabotage, but instead the near miss of a Soviet S-75 Dvina (SA-2) ... caused structural failure of the airframe that brought down his plane.
...
Over the past 50 years additional evidence has surfaced from both sides, which confirms what Powers always maintained, that his U-2 was shot down while flying at an altitude of 70,500 feet over Sverdlovsk.
As a result of declassified documents pertaining to the U-2 Incident, the USAF recently determined that ... sustained courage in an exceptionally hostile environment demonstrated gallantry that rises to the level of a Silver Star. The posthumous awards ceremony for Powers’ Silver Star will take place in 2012 once the USAF decides on a date and time. For my father and the Powers family this posthumous award 50 years after the fact goes to show that it is never too late for a government to help set the record straight.
Francis Gary Powers, Jr is the Founder and Chairman Emeritus of The Cold War Museum (www.coldwar.org).
Posted by Francis Gary Powers, Jr. on March 27,2012 | 08:41 AM
It was fascinating to read about Ken Weir's two great U-2 saves. Unfortunately, he repeats the old myth about Gary Powers descending over the Soviet Union before he was shot down. In the immediate aftermath, this was widely believed, but it just wasn't the case.
Chris Pocock
author, 50 YEARS OF THE U-2
Posted by Chris Pocock on March 27,2012 | 05:49 PM
I will defer to Frank's son Gary on this one. He has had to spend an inordinate amount of time over many years to set the record straight and obtain the proper recognition that his father so rightly deserved and was wrongly denied by an ungrateful administration at the time following the loss of the U-2 #360 over the Soviet Union.
I was flight testing F-104s at Lockheed in the late 1960s and had very little direct contact with his father.
Frank was extremely well liked by all of the other Lockheed pilots and they all considered him to be an exceptionally skilled U-2 test pilot. I was later assigned as a test pilot to the Lockheed U-2 program in 1972.
Before I pushed the send button responding to the transcript of our interview knowing full well some purist would take exception to any mistake I would make I went back to my personalized autographed copy of Frank's book Operation Overflight published in May 1970 and checked several items.
Page 81 second paragraph "Predictably, number 360 chose this moment to be unpredictable. The autopilot began malfunctioning, causing the aircraft to pitch up. To correct the condition, I had to disengage the autopilot, retrim, and fly the airplane manually for a few minutes. When I reengaged the autopilot, the plane flew fine for ten to fifteen minutes, after which the pitch controls again went to full nose up position. The aircraft couldn't take much of this. Again I went through the same procedure. With the same result. This time I left the autopilot disengaged."
"Should I go on. I'd have to fly the plane manually the rest of the way."
"It was an abort situation, and I had to make a decision: to turn around and go back, or continue the flight."
"I decided to continue on and accomplish what I had set out to do."
Frank makes no mention in his book of a flame out or of reducing thrust to get to a lower altitude in order to be better able to hand fly the airplane. He did mention the demanding requirement to keep the airplane within the maximum Mach limit and stall speed which is a very small margin particularly so at heavy weight and high altitude. He also mentioned the increased fuel consumption anticipated while hand flying the airplane which would indicate continuing the flight at lower "very high" altitudes. Most folks believed the state of the art for Soviet missiles at the time made the U-2 relatively safe at max altitude but that time was indeed running out as the subsequent loss of Chinese U-2s would reveal. Nearly everyone agrees, I believe, that the SAM did not obtain a direct hit on Frank's U-2 but detonated close by, a "near miss". I believe the SAM would have more than likely made a direct hit on the airplane had Frank been well below 70,000 feet. Frank was recognized as a very gifted experienced pilot and perhaps he was indeed able to keep it under control at the maximum cruise climb altitude for which he should have been commended because that is a very difficult bit of airmanship which the average U-2 pilot including me found near impossible to accomplish for extended periods of time not to mention being in the even more hostile environment of SAMs. The information to which I was aware spread around over the ensuing years amongst the U-2 community that he descended somewhat to gain some additional aerodynamic stability and then was upset by a near miss could well have been based on the assumption that trying to wrestle with the airplane at max altitude was too much to deal with and altitude was reduced perhaps to 70,500 to get the airplane into a more manageable situation and still continue the mission. I believe the "assigned altitude" was in most cases not a constant altitude because that did not utilize the airplane's true altitude performance capability. It was the practice that I experienced to nearly always fly as high as the pilot could reach within the maximum EGT limits and as the flight continued and fuel was consumed the airplane became lighter and continued to climb to higher altitudes.
It is interesting to note that as the U-2 became lighter and lighter and could reach higher altitudes the margin between stall and Mach buffet first decreased and then later increased and was thus easier to cope with. Certainly no one can accuse Frank of not carrying out an assigned order, endangering his airplane or jeopardizing his assigned mission if he did indeed reduce his altitude slightly so that he could complete his assigned mission under what was then and now considered at least a deferred emergency and an abort situation. I sure hope no one is splitting hairs over "flying at a lower altitude" with an airplane first built in 1955 still capable of setting altitude records today with or without an autopilot in the hands of an accomplished pilot. The fact that Frank was hand flying the U-2 at high altitude after some four hours into the mission when the SAM near miss occurred is more indicative of his valor than anything else regardless of what actual "high" altitude the event took place. Frank was flying the airplane yoke, rudder and throttle with a set of golden hands and silver feet. The mal functioning autopilot was not flying the airplane and for that he exhibited exceptionally distinguished airmanship of the highest order. In no way should the significance of what Frank experienced on 1 May 1960 be diminished if he did or did not descend a couple of thousand feet while hand flying the U-2 to avoid the "coffin corner" of the climb envelope on a classified reconnaissance mission over denied territory. Frank's son Gary is to be commended for doing everything he could over the years to see to it that his father received the Silver Star and all of the other USAF and CIA awards that Frank richly deserved. And for setting the record straight with me also, thanks.
Posted by Ken Weir on March 28,2012 | 02:46 PM
And I will most definitely defer to Chris Pocock; he is with out a doubt the foremost authority and expert on all things pertaining to the U-2! There is no other aviation history book about any airplane anywhere that I know of like his "50 years of the U-2"!
Obviously I feel all the pilots who struggled over the years flying the U-2 never “get any respect”. In the context of the Air and Space interview I tried to describe, based on my nearly 4800 hours flying the airplane just how difficult, at least for me, the U-2 airplane was to fly.
I hope no one overlooks that aspect of the Dragon Lady. Sitting up there above 70,000 feet in a pressure suit balanced on the head of a pin hours on end isn't exactly a walk in the park. Then at the end of the long flights having to get psyched up to deal with the most difficult of all airplanes to land ever built was very demanding.
I have heard several individuals who have never flown it say that "flying the U-2 has to be like watching grass grow."
Xray One One
Posted by Ken Weir on March 29,2012 | 04:07 PM
i take exception to the notion that Gary elected to lower his cruise altitude as he approached Sverdilov. The basis for this comes from remarks made by Gary at our Dine In event at Davis-Monthan AFB after his release from captivity.He was our featured speaker that was telling us in extensive detail the minute by minute events in the codkpit at that particular period of time leading up to the shoot down. He was among many of his former F84 pilot friends and of our U2 Unit. I have to believe that his remarks would have mentioned the fact that he had elected to descend a few thousnd feet. Another fact bearing on the matter is that the situation that prevails with your power setting at max cruising altitude is extremely sensitive to any reduction in that you are inviting a possible flame-out. Over USSR would not be a place where you would chance that possibilty. There are too many "experts" trying to build their case without any basis for their theories.
Posted by anthony martinez on April 19,2012 | 07:14 PM
General Weir,
My classified thesis at Air Command & Staff College included a section on Frank Powers mission. I was fortunate to be able to access classified reports and congressional testimony at the wonderful library there at the Air University. Let me just say that Frank Powers was a certified hero and deserved far more recognition than was permitted. I've told his son this. If you can gain access to the classified library please do so to confirm General Weir's accurate assessment of Frank's skill and bravery. I flew the U-2 from 1978-1990 and during the Iranian crisis in 1979 had the autopilot fail in pitch only..I hand flew her in pitch for 9 hours...it was a bear. Frank had lost all axis...all axis.. and pressed on.
That said, one personal aside to the General: 1978. Your R model ferry flight PMD-BAB. A "No call" landing. Your comment to a brand new U-2 pilot/mobile (me) after parking the jet..."Son what will it take for you NOT tell anyone about that landing?" "Those Doe Skin gloves sir". I still have them. Best wishes sir...Paul "Bugs" Roberts
Posted by Paul Roberts on April 20,2012 | 10:00 AM
Sam-2 NATO designation,(C-75 Russian designation) early versions known as Dvina and later as Volga are NOT designed to directly hit the target airplane. It's ~250KG warhead is designed to explode at 50 to 150 meters (164 to 492 ft) from the target.
If the distance between the missile and the target was decreasing and approached the 50 meters distance from the plane a proximity fuse or a ground command from the guiding computer (called AZVAKA) orders the detonation. But if the distance between the missile and the target begin to increase while the missile is in the range between 50 and 150 meters from the target then AZVAKA sends detonation command to the warhead because it understands that increase in distance as if the missile is going to miss the target and it is.
Posted by Bassim Ismail on April 23,2012 | 06:04 PM
I read the interview with Ken Weir and have to say that "X-Ray 11" (his radio call sign) was one of the best, if not the best pilot to do business with. Ken and I talked via radio as he was flying EW test missions for me over the Nevada Test Ranges and if things did not go per the test plan, Ken was always up to my having him do a little extra in the cockpit. Before GPS, after being airborne the U-2 would tend to drift and deviate from the reqired track. All I had to do was call X-Ray 11, and tell him he was a quarter mile right or left and I swore that Ken had a special sagebrush picked out on the ground that he could see as he would make a slight course correction, call out "how's that?", and he would always be right back on track again. There are many other stories I could tell about those times with X-Ray 11 over the test ranges, but that is for another time.
Unlike some of the pilots I delt with, there was nothing that Ken would not do to assure we got the most out of a mission. All Lockheed test pilots were a cut above and were easy to work with. THX "X-Ray 11", for all of the good work back in those days.
A short story pretaining to Francis Gary Powers. After his release from Russia, several times he flew me from Burbank to a site in Nevada in one of Lockheed's company planes. In those days we were testing the early DEF Systems on the SR-71 and on one particular day, the SR was delayed so the mission time also slipped. During the delay, Gary and I were sitting in an office along with several other site personnel having coffee and general chit-chat. The subject soon turned to Gary Powers and that day in May 1960, when the shoot down occured. Everyone sitting in that room seemed to have a theory about how it happened. I recall that during the entire discussion Gary never looked concerned and never said a word. No one knew that sitting in that room next to me was Gary Powers himself!
From a retired Lockheed Avionics EW Test Engineer. 1982-1999.
Posted by Richard Cooney on May 5,2012 | 04:35 PM