GE Aviation’s workhorse helicopter engine, the T700, has been going strong for 42 years and counting.
In the spring alone, the company was awarded $242 million in military contracts. This includes a $62 million contract modification to manufacture T700 engines for Black Hawk helicopters for the U.S. Army and international customers. Then in June, GE signed a five-year, $180 million contract with the U.S. Naval Air Warfare Center Aircraft Division (NAWCAD) to repair and overhaul T700 rotorcraft engines in support of the U.S. Navy’s MH-60 Seahawk, and the U.S. Marine Corps’ AH-1Z Viper and Bell UH-1Y Venom/Huey helicopters.
GE’s great run producing helicopter engines began in 1954 with the introduction of the T58, a turbine engine that weighed 250 pounds and produced 1,050 shaft horsepower. It was the first turbine engine certified by the FAA for civil helicopter use and the T58 firmly established its reputation over the next few decades as one of the most reliable helicopter engines, powering Marine One—the U.S. President’s helicopter transport—and other diverse applications.
By 1967, the helicopter landscape changed. With the Vietnam War, military helicopters assumed major roles both as combat vehicles and as troop transports in hostile environments. With U.S. government seed money, studies commence on the GE12 demonstrator.
The GE12 design was nothing short of revolutionary: the first axial-centrifugal (impeller) compressor. The first stages are axial with compressed air moving parallel to the engine centerline to the centrifugal stage, where the impeller spins compressed air from the center toward the outside.
In 1972, the U.S. Army launched a production version of the GE12 called the T700, which would become the most popular turboshaft engine for military and civil helicopters for more than a half-century. The T700 set a milestone as one of the most-produced engine families in aviation history.
Upon service entry in 1978 in the Sikorsky UH-60 Black Hawk, the T700 quickly proved its mettle in helicopter service, and its operational benefits also made it an ideal derivative as a turboprop powerplant.
Today, the T700/CT7 family of turboshaft and turboprop engines power 15 types of helicopters and fixed-wing aircraft with more than 130 customers in more than 50 countries. The T700/CT7 family has surpassed 20,000 units delivered and more than 100 million total flight hours. They serve five branches of the U.S. military, numerous international customers and civil aviation operators.
Current models in the 2,000-3,000 shaft-horsepower range retain all the proven features and operating characteristics of earlier versions while delivering enhanced performance.