LYNN ? Executives, rank-and-file workers and military brass at GE Aviation in Lynn are celebrating production of the 15,000th jet engine for the Black Hawk and Apache military helicopters.The milestone was reached Oct. 6 when the T700/CT7 engine was delivered during a ceremony at the Western Avenue facility. Hundreds of employees and retirees attended the along with special guests from the U.S. Army, Navy and Marine Corps, as well as key airframe customers.The engine powers the Sikorsky Black Hawk troop transport and utility helicopter and the Boeing AH-64 Apache attack gunship.”The T700/CT7 engine is a remarkable story, one that just continues to evolve,” said Ed Birtwell, vice president of GE’s Turboshaft/Turboprop Project Department. “Its longevity and success are only possible because of the engine’s performance in the field, our great customers, and the commitment of our employees to design, manufacture, assemble and test the best engines in the world.”The engine emerged in 1967 as the GE12 demonstration. By 1972, GE had been awarded full-scale development and two later the T700 flew for the first time. In 1976 the engine was qualified for operational service, paving the way for the inaugural engine delivery in 1978.Over the years, GE has kept up a steady production of the award-winning engine, reaching the 10,000 mark in 1996.Lt. Gen. James H. Pillsbury, U.S. Army Materiel Command deputy commanding general, applauded GE workers for their role in making the T700/CT7 a mainstay engine line for the nation’s defense. “Thanks to the T700 engines and the platforms they power, our soldiers and pilots can accomplish their important missions. You are a valued partner; and the T700 plays an important part in helping us maintain global security,” he said.Members of the GE assembly team presented the 15,000th engine certification to Air Force Lt. Col. Kevin Sellers (USAF), Defense Contract Management Agency Commander at GE Aviation, at the conclusion of the event.Developed for the U.S. Army to overcome the many obstacles 1960s-era helicopter engines experienced in Southeast Asia, the T700/CT7 turboshaft was designed to operate reliably in any environment and be easily maintained, said Richard Gorham, a GE spokesman in Lynn.Upon service entry in 1978 in the Black Hawk, the engine quickly proved its mettle in helicopter service, and its operational benefits also made it an ideal turboprop powerplant, said Gorham, noting that current models in the 1,500 to 3,000 shaft-horsepower range retain all the proven features and operating characteristics of earlier versions while delivering enhanced performance.The T700/CT7 family of turboprop and turboshaft engines currently powers 25 types of helicopters and fixed-wing aircraft in service with more than 130 customers in more than 50 countries.”This engine family has accumulated over 50 million engine flight hours of experience,” Gorham said.The engine powers a variety of commercial and military applications including transport, utility and attack, medical evacuation, air rescue, special operations and marine patrol. They serve all five branches of the U.S. military and numerous international customers, Gorham said.The most common applications include the Sikorsky Black Hawk, Sea Hawk, Jay Hawk and Pave Hawk, and the AH-64 Apache.