TINKER AIR FORCE BASE, Okla. -- When TF33 engines first started powering B-52s in 1961, the Shirelles were enjoying Billboard fame with their No. 1 hit, "Will You Still Love Me Tomorrow?"

For the TF33 54 years later, the Air Force can still answer yes. First designed in the late Fifties, the Pratt & Whitney workhorse continues to propel front-line Air Force aircraft.

Jet engine mechanic Wade Waller has been working on TF33s for about two decades. The 545th Propulsion Maintenance Squadron member compares the difference between working on the TF33 and newer engines to going from a manual finger-powered typewriter to the relative ease of an electric model.

"It takes a lot more customization," Mr. Waller said. "It's a lot more than the plug and play type that the new engines seem to kind of have."

The Air Force began using the TF33 to power B-52 Stratofortresses in March 1961 and it still uses them today. The engine also has been keeping E-3 Sentry Airborne Warning and Control System planes flying since 1973, according to Pratt & Whitney.

The company built about 8,600 TF33s for commercial and military use since production began in 1959. Engineering improvements were added over the years until the last one was made in 1985.

"There have been a lot of changes," Mr. Waller said. "It's not the same engine they used back in the '50s, but on the other hand, it is the same engine."

Jeff Atwood, work director/training leader with the 545th PMXS and a 34-year engine line employee, said post-production engineering improvements have changed the engine's performance over time.

"I enjoy working on TF33s because most of the repairs have been done before and they're easy to fix," Mr. Atwood said. "We've also raised the time allowed on the wing. The engines are staying on the wing longer than they ever have - longer than they did when they were brand new."

The 545th PMXS, based in Bldg. 9001, relies heavily on TF33 engine parts from Davis-Monthan AFB, Ariz., home of the Air Force boneyard of planes in long-term "mothball" storage. If parts aren't available there, they have to be remanufactured, Mr. Waller said.

Restoring mothballed engines can pose special challenges at times, Mr. Waller said. One engine the squadron worked on needed an oil tank, which on TF33s bends at odd angles.

A contracting company built several tanks from blueprints, only to find that the tanks fit poorly on the engine, Mr. Waller said. Design engineers visited Tinker and worked out a solution.

"These oil tanks are an extremely complicated assembly," Mr. Waller said. "I'm not sure how they ever built one, blueprints or not ... but the solution worked very well, allowing us to purchase the oil tanks. We felt that their team did a great job."

Billy Stilley, the TF33/F100 logistics management section chief, said diligent maintenance scheduling has made the TF33 a safe and reliable engine, despite its age. 

"The reason the Air Force is still flying the TF33 engine on various platforms is that the engine still meets the aircraft operational requirement in terms of capability and cost," Mr. Stilley said.

TF33s do have downsides, including relatively low fuel efficiency, Mr. Stilley said. The Air Force is evaluating the possibility of a new engine to power B-52s, he said.

"While generally reliable in terms of time between overhauls, many newer generation turbofan engines experience greater reliability than the TF33 with much higher fuel efficiency," Mr. Stilley said.