Pratt & Whitney’s TF33 Engine Celebrates its 55th Year with a Promise of Many More to Come

Pratt and Whitney tf33

Gary Ransom, customer support engineer, Military Engines, recently looked over drawings of a compressor blade for the TF33 engine. The date of one drawing was April 6, 1959.

„I suddenly realized I was exactly one month old when the drawing was produced,” Ransom said. „It certainly points to the fact that this engine has been around for a very long time.”

The TF33 and its commercial variant, the JT3D, celebrated its 55th anniversary in June. The JT3D was the first turbofan engine designed and produced by Pratt & Whitney. When it was introduced, the engine had approximately 50 percent more take-off thrust, 25 percent more climbing power and 20 percent greater power at maximum cruise than previous engines.

„It’s a very versatile engine,” Ransom added, „with the ability to power high-altitude, reconnaissance aircraft; bombers; and aircraft doing low-level aerial delivery. And its reliability has been exceptional.”

First introduced on the U.S. Air Force’s B-52H long-range, eight-engine Boeing intercontinental bomber, the TF33 continues to serve that fleet today and is also on AWACS (Airborne Warning and Control System), the Joint Stars and some special mission aircraft. In addition to the Air Force fleet, the TF33 powers NATO AWACs and KC-135s for Chile. Over the past six decades, it also has powered the C-135, C-141, EC-135, RB-57, E3A, C-135 and KC-135, as well as the VC-135, which served U.S. presidents as Air Force One from Richard Nixon to George W. Bush.

Ransom joined Pratt & Whitney 10 years ago after retiring from the Air Force as a C-141 crew chief. Putting the two stints together, he has been associated with the TF33 for 35 years. „I flew aircraft with this engine all over the world during my Air Force career,” he said. „You might say I’m very comfortable with the product.”

Today he supports the TF33 as well as other legacy Pratt & Whitney engines, holding maintenance awareness briefings at all Air Force bases operating the B-52, and conducting training sessions with service maintenance personnel, mechanics and pilots. Pratt & Whitney has one roving field representative for the TF33, Wesley Jacobs, also retired from the Air Force, who’s based in Oklahoma City.

Ransom said a primary responsibility is compiling the biggest issues his Air Force customer is having in the field and then doing engineering changes and component improvements, as well as working obsolescence issues. He noted that the TF33 is expected to remain active on the B-52H fleet until 2045, and that obsolescence issues are being worked to extend its life out until 2070.

„Like most engines, nobody thought the TF33 – or the B-52H is powers – would go on for so long,” he said. „It’s a testament to the reliability and performance of the power plant.”

The last new TF33 was produced in 1985. Still, with approximately 1,100 engines in use – more than 800 in the B-52H fleet – the ability of suppliers to make parts for the engine remains a critical component.

„It’s one of our biggest challenges, ensuring we have the parts to keep the engines running,” Ransom said. „It can be a challenge to make a part from a drawing that’s more than 50 years old.”

As a young boy growing up in Connecticut, Ransom wanted to work at Pratt & Whitney. He’s an avid aviation enthusiast (he once had his pilot’s license) and got to pursue his dream in the Air Force. When he retired, coming to Pratt & Whitney was a perfect fit.

„However, despite my experience with the TF33, I emphasized my experience with the C-17 on my resume,” Ransom said. „It didn’t occur to me they’d be interested in my TF33 background. Once I got here and they found out about my relationship with the engine, I became the 'TF33 guy’ for the company. I’ll get asked questions about the engine and I’ll think, 'Well, everyone knows that.’ But you come to realize they don’t teach about the old engines anymore. The world has moved on.”

Still, Ransom has become a valuable resource to employees working on Pratt & Whitney’s latest technology engine programs.

„I’m constantly getting asked questions about TF33 engine performance. They’re interested in such things as knowing why the engine performs so well in severe conditions, like ice build-up. Because the TF33’s performance has been so exceptional for so long, its durability is something that’s being studied and utilized in the design of the company’s future propulsion systems.”

Source / Author: Pratt & Whitney

Photo: Pratt & Whitney