U-2 Dragon Lady: We Know Wings
Maintenance. Everyone does it and everything needs it. Humans maintain their strength by eating food. Cars are taken in for oil changes every 3,000 (or 5,000) miles. Birds maintain top flying condition by molting wings.
Ah…wings. What’s in a wing?
For the U-2S, it’s a 103 foot wingspan that allows it to soar at 70,000 feet; but, what’s truly impressive is the lifespan of the U-2 wing, an astounding 75,000 flight hours, which means the U-2 can fly well beyond 2045, more than 30 years.
Yes, that’s right. Thirty. Years.
Equally impressive is the U-2 high aspect ratio wings that provide the U-2 with glider-like characteristics. With a glide ratio of approximately 23:1, the U-2 can glide for more than 300 miles from an altitude of 70,000 feet.
Maintenance Confirms Integrity
As with anything, wear and tear is inevitable, but regular maintenance keeps things working day in and day out.
Programmed Depot Maintenance (PDM) is the U-2’s version of maintenance, and is performed every seven years or 4,800 flight hours. PDM involves the complete disassembly, inspection, repair and reassembly of the entire aircraft; ensuring its longevity and ability to fly at today's record-high operational rates.
While the design provided the foundation of the U-2 wing’s lifespan, PDM ensures that the wings are in tip-top shape.
“PDM is incredibly thorough, to the point the U-2 comes out virtually new,” said Melani Austin, U-2 program director. “It’s this thorough maintenance that allows us to collect data on airframe and wing integrity, confirming its lifespan of 75,000 flight hours.”
With a clear guide and process in place, the wings team consistently delivers results, recently passing their 25th consecutive mandatory government inspection with zero defects.
Striving for Excellence
“As a team, we expect to always do better,” said Brent Newman, U-2 wings supervisor. “We don’t want to get complacent. We’re always looking to improve in any way we can to support the U.S. Air Force and their pilots and maintainers.”
In fact, the team delivered the lowest cost wing in the history of the program late in 2015, reducing hours by half –including the teardown and buildup phases– by introducing new processes and helium testing.
Leaks are a normal occurrence for any aircraft, manned or unmanned, and were previously identified through leak testing. If a leak was found, it required multiple defuelings to check, fix and test.
“Leak testing used a lot of time and effort, and now with helium testing, we cut that time nearly in half,” said Newman. “Given the small size of the helium molecule, the accuracy in identifying leaks, even incredibly tiny leaks, improved drastically. That ultimately helps us turn out an even better quality wing.”
And, cost continues to go down.
“Every little bit we can do to drive down cost and improve performance contributes to the safety of troops on the ground and the U-2 pilots coming home,” said Newman. “It’s why we do what we do.”