The jet’s first engines, called the TF39, used a design called a high-bypass turbofan, which placed a big fan up front to generate thrust in combination with a jet. GE had to test the engines on a B-52 bomber, the closest plane in size to the gigantic C-5, which can lift 130 tons of cargo and has a range of 5,000 miles at 500 miles per hours.
Today, virtually every mid-size and large commercial plane uses the same engine design, but back then, the TF39 was revolutionary. It allowed GE engineers to boost the engines’ thrust to 40,000 pounds each and cut fuel burn by a quarter compared other engines in use at the time
GE quickly saw the commercial potential and built a passenger version called the CF6. It first flew in 1971, and today, it is one of the most common jet engines in the world, powering all makes of planes, from Boeing 747 jumbos—including President Obama’s Air Force One—to Airbus long-haul jets and Beluga cargo lifters. GE has delivered more than 7,000 of them to 250 airlines in 87 countries. The newest versions on the engine are expected to fly until 2040.
The plane that landed in Oshkosh—the C-5M Super Galaxy—was delivered to the Travis Air Force Base in California in 2014 and uses a military version of the CF6 engine. It allows the plane to use less runway and take off faster compared with the original TF39.
But jet engine evolution didn’t stop with the CF6. GE engineers used their knowledge to build the GE90, the world’s most powerful engine with thrusts of up to 127,500 pounds, the GEnx for the Boeing Dreamliner and 747-8 jumbo, and the GE9X, the world’s largest engine developed for Boeing’s next-generation 777X plane.
New materials such as carbon fiber composites for fan blades and fan cases, and modern designs cut weight by hundreds of pounds and boosted thrust. The latest engines like the GE9X and the LEAP, developed by CFM International—a joint venture between GE and France’s Safran Aircraft Engines—even use 3D-printed parts and space-age ceramic composites. “Four decades from now, we could be printing an entire engine this way,” said Michael Idelchik, former vice president for advanced technologies at GE Global Research, who was involved in the research.
While at Oshkosh, we took a close look at the Galaxy and its engines. Here’s the haul.