The U-2 Dragon Lady is one of the most consequential planes ever built. Unfortunately, it’s also notoriously difficult to fly.
Throughout the Cold War and post-Cold War eras of accelerated aerospace development, the U.S. Air Force has relied upon a single, unchanged, relatively simple reconnaissance aircraft—the U-2 Dragon Lady, which first flew in 1955 and still serves today. The U-2 is notable for its extremely high service ceiling of about 70,000 feet—high enough to see the curvature of the Earth, and an altitude at which pilots must wear pressure suits, lest their bodily fluids begin to boil.
For seventy years, the U-2 has flown high above the Earth. It has contributed to U.S. intelligence gathering operations as far back as the Cuban Missile Crisis, and as recently as the ongoing migration crisis along the U.S.-Mexico border. Yet the U-2’s venerable service life is quickly coming to a close—with withdrawal expected to begin within the next several months, in preparation for a final retirement sometime within the next few years.
The U-2 bears resemblance to, and indeed shares performance characteristics with, a glider. The fuselage is long and slender. The wings are massive relative to the size of the fuselage, with a total area of 1,000 square feet. And, much like a glider, the U-2 had a remarkable engine-out glide ratio—the ratio of how far forward an aircraft travels relative to how much altitude the aircraft loses—of 23:1. In other words, if the U-2 were to lose power to its engine, it would glide forward 23 miles in the time it took to lose one mile of altitude. To put that in perspective, the F-16 Fighting Falcon has a glide ratio of just 7.8:1.
But unlike a glider, the U-2 was built around an engine, specifically the General Electric F118 turbofan (and formerly the Pratt & Whitney J57, and later J75, engines). The F118 produces about 17,000 pounds of thrust, which gives the lightweight U-2 a generous thrust-to-weight ratio of 1.06:1.
The U-2 is notoriously difficult to fly. As former U-2 pilot (and later NASA Director of Flight Operations) Martin Knutson said, the U-2 “was the highest workload air plane I believe ever designed and built … You’re wrestling with the airplane and operating the camera systems at all times,” which leaves zero time to “worry about whether you’re over Russia or you’re flying over Southern California.”
And to maintain altitudes around 70,000 feet, the U-2 needed to be flown very near the aircraft’s ‘never exceed’ speed—which happened to be only about ten knots faster than the aircraft’s stall speed, meaning the pilot’s margin for error with respect to airspeed was razor-thin.
Landing the U-2 wasn’t much easier. The U-2’s flight controls were calibrated for high-altitude flight, where the air is extremely thin; the U-2 was configured in such a way that control inputs at high-altitude require a very light touch. However, once the plane descended back to lower altitudes where the air was denser, control inputs required a heavy, indeed forceful, touch. U-2 pilots actually need a measure of physical strength just to fly their aircraft, an unusual requirement for most modern pilots.
Once the U-2 is wrestled down into the landing pattern, the aircraft is extremely sensitive to crosswinds, and to floating in ground effect. In fact, the U-2’s gliding abilities are so efficient within the ground effect above a runway that the pilot must fully stall the aircraft to get her to land.
The U-2, and the demands she places on her pilots, are very much a relic of a bygone era. When the U-2 is finally retired, we shouldn’t expect to ever see anything quite like her ever again.
About the Author: Harrison Kass
Harrison Kass is a senior defense and national security writer with over 1,000 total pieces on issues involving global affairs. An attorney, pilot, guitarist, and minor pro hockey player, Harrison joined the U.S. Air Force as a Pilot Trainee but was medically discharged. Harrison holds a BA from Lake Forest College, a JD from the University of Oregon, and an MA from New York University. Harrison listens to Dokken.
Image: Wikimedia Commons.
