Maintenance records of the 55th Wing are filled with examples of electrical failures and circuit breakers being tripped.
One incident on March 14, 2017, shows just how serious such problems can be. The electrical systems failed on a RC-135V during aerial refueling 100 minutes after taking off from Al Udeid Air Base in Qatar.
The jet and its 55th Wing crew from Offutt were starting a long mission in support of U.S. and allied forces in Afghanistan. The crew, including a contingent of Air Force-trained translators of Afghan languages, were there to use the Rivet Joint's sophisticated listening gear to intercept enemy communications and pass along intel to friendly forces.
While slurping fuel through a boom dangling from a tanker flying just above and ahead of the RC-135, the pilots' instruments suddenly went dark. So did almost everything else on the aircraft.
The switch DC bus, which takes power from the plane's engines and feeds it to electrical components, had failed. The jet lost all flight displays, rudder controls, radios and its flight computer. The pilot backed away from the tanker but kept following it so they wouldn't get lost. After 10 minutes, the crew found an open circuit breaker and reset it, restoring power.
Their troubles weren't over, though. Twice more the power failed. Finally, on the fourth reset it stayed on, after the pilot told the airmen in back to shut down all their intelligence-gathering equipment.
The pilot declared an emergency and headed back to Al Udeid with the tanker escort. Three tense hours later, the plane landed safely.
That incident mirrored a similar one aboard another reconnaissance flight out of Qatar 2½ years earlier. That flight was refueling en route to a combat sortie when a warning light showed that the left outboard engine had overheated.
Following procedures, the crew shut down the engine, and the DC bus failed.
“Immediately the mission compartment was plunged into darkness,” the pilot wrote in a post-flight report. “The autopilot disconnected, and the pilots’ instruments lost most of their indications.”
The crew managed to get a radio message off to the tanker and followed it back to base, declaring an emergency. They managed to restart the DC bus and land safely — with one engine still out — in Qatar.
In-flight electrical failures disturb former Air Force and airline pilot Frank Strickler, who racked up 5,000 hours flying the Boeing 707, the C-135's civilian cousin. He also investigated numerous crashes for the Federal Aviation Administration. He called the tripped circuit breakers “a super-serious failure of some kind.”
“There’s a short-circuit someplace,” said Strickler, who lives in Ringgold, Texas. “If that keeps happening, you’re going to lose the airplane.”
Though they were replaced when the RC-135 Rivet Joints received engine upgrades in the 2000s, the generators on those RC-135s are taxed because of the enormous amount of electrical power required to run the high-tech surveillance gear carried in the aircraft's cabins, in addition to powering the flight-control systems.
“The Rivet Joint is full of avionics, heat and people,” said retired Lt. Gen. Thomas Keck, who commanded the 55th Wing from 1993 to '95. “It’s a more stressful environment.”
Retired Col. Roger Craig of Glenwood, Iowa, used to fly the RC-135 and went on to serve as deputy director of the Air Force Safety Center. He said the reconnaissance mission takes these airplanes a long ways from their roots in the early days of airline travel.
“Bill Boeing probably never intended for all this exotic stuff to be in the back of the plane,” Craig said.