As of June 3, all CF6-6 engines, the original CF6 engine variant, are officially retired.

These are some of GE Aviation's oldest operating commercial jet engines, one of which had reached more than 49 years and 6 months of service before its final flight.

FedEx retired its fleet of long-running CF6-6D engines installed on McDonnell Douglas DC-10-10F aircraft. All CF6-6 engine models entered service on passenger airplanes before they were repurposed for cargo operations.

The retirements are just two months shy of a major milestone for GE's CF6 engine program. In August, the CF6 program marks 50 years of revenue service, beginning with the first CF6-6 to fly on a McDonnell Douglas DC-10-10 in 1971 with American Airlines and shortly after, United Airlines. The CF6-6 helped jumpstart GE Aviation's commercial aviation business and became GE Aviation's first successful widebody commercial aircraft engine program, helping make international passenger travel available to more people.

Altogether, the CF6 program has reached more than 460 million engine flight hours across all models since its 1971 debut.

"While this is an end of an era for CF6-6 engines that helped establish GE Aviation's commercial engines business, the retirement of CF6-6 engines after nearly 50 years is a testament to the reliability of the engine product. Operators around the world have continued to count on CF6 engines throughout the global health pandemic to help deliver freight and important medical supplies," said Mike Kauffman, general manager of the CF6 engine program for GE Aviation.

Over its nearly half century of flight, the oldest running CF6-6 engine clocked more than 92,000 engine flight hours and over 34,000 flight cycles. Another CF6-6 engine reached 45 years and 8 months of service before it was retired in December 2020 and amassed over 95,000 engine flight hours.

While all CF6-6 engines are now retired, the remaining CF6 engine models—CF6-80C2, CF6-50, CF6-80A and CF6-80E1—continue to operate. The CF6 engine program, with 10 aircraft family applications, is one of the longest running jet engine programs in commercial aviation. In fact, CF6-80C2 engines for Boeing 767 aircraft continue to be manufactured, making CF6 also one of the longest-running production engines in commercial aviation.