The U.S. Air Force discovered a fan blade defect in Pratt & Whitney’s F100-PW-229 fighter-jet engine while investigating a mishap, according to service officials.

“Once they tore into the root cause [of the mishap], they noticed that there was a defect with the actual blades in the engine,” said Maj. Gen. John Rauch, commander of the Air Force Safety Center at Kirtland Air Force Base in New Mexico. “So [they] went back, discovered that it was a manufacturing process and then real quickly, time critically, went across the fleet.” 

A U.S. Air Force F-16. Photo: Air Force.
A U.S. Air Force F-16. Photo: Air Force.

So far, 94 percent of active engines, including spares, and more than 15,000 fan blades have been inspected with a borescope, the safety center said in a statement. As a result of those inspections, 163 fan blades, or more than 1 percent, were deemed defective and removed, Rauch testified at an aviation safety hearing June 13 before the House Armed Services Committee’s tactical air and land forces panel.

The F100-PW-229 engine powers F-15s and F-16s. The defect was found while the Air Force was investigating a Class A mishap, the most serious kind of accident. The Air Force declined to say more about the mishap.

Pratt & Whitney, a division of United Technologies Corp. [UTX], declined to comment on the matter, referring questions to the Air Force. But according to a company website, the F100-PW-229 “has the best safety record of any increased-performance engine.”

The family of F100 engines has been selected by 23 air forces and amassed more than 24 million flights. Pratt & Whitney has built more than 7,200 F100s.