Old Bird Learns New Tricks

The oldest Lockheed Martin F-22 Raptor in the United States Air Force – tail number 91-4006 – just came out of retirement and took to the skies.

September 21, 2018

William Kucinski

Raptor 4006 takes off for the first time in nearly six years with Steve Rainey, Lockheed Martin F-22 chief test pilot, behind the controls, July 17. The test jet recently completed an extensive refurbishment after a period of long-term storage. It will now be used as a flight sciences aircraft for the 411th Flight Test Squadron and F-22 Combined Test Force. (Image source: Chad Bellay/Lockheed Martin)

United States Air Force (USAF) boasts that the Lockheed Martin F-22 Raptor fifth-generation air superiority fighter cannot be matched by any known or currently projected fighter aircraft. The aircraft’s combination of stealth, supercruise capability, maneuverability, and integrated avionics, represents an exponential leap in warfighting capabilities from previous generations of fighters. Which is great. Really great. But it also makes them very, very expensive.

Case in point: Since May 2001, the oldest Raptor in the USAF – tail number 91-4006 – had been assigned to the 411th Flight Test Squadron (411^th FLTS) and F-22 Combined Test Force (F-22 CTS) at Edwards Air Force Base , Calif. It was an early Block 10 version of the aircraft, and in November 2012, it needed $25 million worth of avionics, electrical and hydraulic system, and flight control upgrades to bring it up to the current Block 20 standards of more recently produced Raptors.

Twenty-five million dollars was significant scratch to begin with, but then the 2013 US government budget sequestration hit. According to Lt. Col. Lee Bryant, 411th FLTS commander and F-22 CTF director, that’s why Raptor 4006 – a $150 million aircraft – was retired and relegated to long-term storage, possibly never to fly again.

The Phoenix Rises

After eventually getting approval and funding from the USAF to overhaul Raptor 4006, a “purple team” of USAF, Lockheed, and Boeing personnel worked for 27 months at Edwards Air Force Base to restore the jet back to flying status.

The work included 25,000 man-hours and almost 11,000 individual fixes and parts. The completed refurbishment extends the Raptor’s life from 2,000 flight hours to 4,000 flight hours and gives it newer avionics systems for testing.

Raptor 4006 is currently the oldest flying F-22. It will now be used as a flight sciences aircraft, which will be an integral part of F-22 fleet modernization.

“It increases our test fleet from three to four giving us another flight sciences jet,” says Lt. Col. Lee Bryant. “This will help us tackle the expanding F-22 modernization program.”

There are only 183 F-22 Raptors in service. As the Lockheed Martin F-35 Lighting II falls short of matching the Raptor’s capabilities and estimated $50-billion cost of restarting Raptor production, modernization – especially of the aircraft’s avionics system – is necessary for maintaining its status as top dog.

William Kucinski is content editor at SAE International, Aerospace Products Group in Warrendale, Pa. Previously, he worked as a writer at the NASA Safety Center in Cleveland, Ohio and was responsible for writing the agency’s System Failure Case Studies. His interests include literally anything that has to do with space, past and present military aircraft, and propulsion technology.

Contact him regarding any article or collaboration ideas by e-mail at This email address is being protected from spambots. You need JavaScript enabled to view it..