The United States was still deeply enmeshed in the Vietnam War when Gerhard Neumann, an engineer who helped launched the jet age as well as GE’s aviation business, visited the battlefield. The U.S. military wanted a two-engine helicopter that could fly faster and farther and be more easily maintained in the harsh tropical environment. Neumann, a Jewish war refugee who found a new home in America after escaping Nazi Germany, spent time in the combat zone interviewing Army aircraft maintenance crews to learn more about their needs.
He came home with an idea for a new helicopter engine that would be 40% lighter than existing engines, involving fewer parts and easier maintenance: the T700, which entered service in 1978, powering the U.S. Army’s Sikorsky Black Hawk helicopters. That same year, the Bee Gees dominated the Billboard Top 100 chart — but while many current and future Army pilots would be stumped to hum a Bee Gees tune today, they’re undoubtedly still familiar with the GE T700. GE has produced more than 20,000 of the engines, including its civilian variant, the CT7. They power 15 types of helicopters and turboprop planes in more than 130 countries, and have accrued more than 100 million flight hours. And they’re far from finished racking up those hours: Last month, the Army awarded GE Aviation a contract valued at more than $1 billion for as many as 1,700 T700 engines through 2024.
Like any enduring piece of technology, the engine has changed dramatically since its introduction. The many technological breakthroughs that have led to the modern-day T700 include a boost from 1,500 horsepower to between 2,000 to 3,000 horsepower, depending on the application. “GE is grateful to the U.S. Army for the opportunity to continue providing reliable power and support to the U.S. military fleet with our T700 engines,” said Harry Nahatis, vice president and general manager of GE Aviation’s Rotorcraft & Turboprop Engines. “This new contract will extend T700 production to 46 years. The T700 has remained the preeminent medium-lift helicopter engine through continuous infusion of military and commercial technology.”
The contract doesn’t mean GE engineers are standing still. Earlier this year, the Army picked GE’s new 3,000-shaft-horsepower T901 engine for its Future Attack Reconnaissance Aircraft (FARA) program. The Army will also use the T901 to upgrade the engines in two of its helicopter models, the Black Hawk and the Apache.
Building on the T700, the T901 taps into some of GE Aviation’s most sophisticated materials and technology. For instance, several of its components are made from ceramic matrix composites — a breakthrough material that’s 20% stronger and two-thirds lighter than its metal counterparts. The engine also has 3D-printed parts. The technology enabled designers to incorporate more complex shapes than traditional manufacturing can produce. The new design will provide 50% more power and is 25% more fuel-efficient compared with the T700.
But until that engine is ready, the workhorse T700 will be there to manage the transition. As one maintenance pilot says, “I’ve been working with these for 17 years and have never had a reliability issue.”