This June marks the 50th anniversary of GE Aviation’s dramatic return to the airline industry by launching the original CF6 engine on the Douglas DC-10. This seminal milestone put GE on a course to become one of the world’s commercial jet engine dynasties.
1968 was a vastly different aviation world landscape. So, it’s hard to fully appreciate today the significance of the CF6 launch for GE. During that era, Pratt & Whitney dominated commercial jet engines, powering the Boeing 707, 727, 737, and 747 aircraft families, and Douglas DC-8 and DC-9 aircraft families.
GE was (and still is) a world-leading military and helicopter engine provider. The U.S. government in 1966 selected GE to power Boeing’s Supersonic Transport, but Congress cancelled the program before it ever got off the ground.
GE’s airline presence in 1968 amounted to 100 Convair 800 and 900 jetliners. In the late 1950s, GE developed a variant of the J79 military turbojet, called the CJ805, for the Convair 800. For the follow-up Convair 900, GE developed the CJ805-23 with an aft-mounted cruise fan. While Convair planes were the era’s fastest passenger jets, it was a bumpy ride. Plagued by poor aircraft sales and engine technical challenges, GE delivered its last CJ805 engines in 1962.
Mounting the Return
GE’s comeback into commercial jetliners was five years in the making.
In 1963, after GE ran a J79 military engine with a large front fan, GE’s legendary leader Gerhard Neumann had met with U.S. Air Force (USAF) Major General Marvin Demler, head of USAF Research & Technology, and unrolled across his table a cross-section drawing of a high-bypass turbofan engine capable of twice the thrust of current engines. Neumann claimed the design would revolutionize air transportation.
That same year, the USAF launched an engine and airframe competition for the massive Lockheed C-5A Galaxy military transport, then the world’s largest airplane.
The engine decision in 1965 resulted in one of the most important jet engines for both GE and the jet propulsion industry when the USAF selected the GE TF39 turbofan engine. GE’s highly-sporty design had the largest front fan (97 inches in diameter) in jet propulsion at that time, and unprecedented compressor efficiencies and turbine temperatures required to turn it.
With a bold 8:1 bypass ratio achieved by the massive front-mounted fan, the TF39 was a major leap in jet engine design offering record thrust levels and fuel efficiency. GE declared the TF39 would operate 25 percent more efficiently than current commercial airline turbofan engines, a claim later supported during flight tests. The era of the high-bypass turbofan to efficiently power large aircraft long distances was born.
The 41,000-pound-thrust TF39 was a culmination of GE’s best technologies and engines to date: J79 and J85 engine experience, the X353-5 lift fan and CJ805 aft fan innovations, air-cooled turbine blade technologies from the J93, and engine core breakthroughs from the GE1/6 demonstrator tests.
The GE TF39 win over P&W set the stage for a showdown between the two U.S. engine titans in the large commercial aircraft arena. GE announced a commercial variant of the TF39 to compete for future jetliners. GE’s return to the airline industry was now a matter of time.
But first, GE passed on the game-changing Boeing 747-100 in 1967. With demanding C-5 and SST engine commitments, Gerhard Neumann concluded that GE didn’t have the resources to develop another new jet engine in a timely manner. Boeing chose P&W’s JT9D, the first high-bypass turbofan engine to power a commercial jetliner.
By 1968, the U.S. was experiencing an air travel boom with passenger traffic expanding almost 20 percent a year. And the attractive 747 economics with its seating capacity for international routes fueled an industry appetite for larger jetliners with more than 200 seats for domestic routes.
Due to the C-5 Galaxy competition, aircraft manufacturers Douglas, Boeing, and Lockheed enhanced their design capacity for large jet planes and were up for the challenge. At the same time, high-thrust turbofan engines (inspired by the TF39) provided the power and fuel efficiency.
American Airlines proposed a medium-range aircraft to carry 250 passengers and 5,000 pounds of freight from Chicago to Los Angeles. Other leading airlines proposd a 250-passenger aircraft for domestic routes. They wanted the economics that a twin-engine airplane could bring, but no engine maker had been able to meet the thrust requirement.
With a CF6 commercial derivative of the TF39, GE heavily lobbied aircraft manufacturers to pursue long-range jetliners powered by three engines. GE influenced Douglas Aircraft to pursue the DC-10 while Lockheed pursued the L-1011 design. Both were three-engine airplanes.
“We went to American Airlines and United, the biggest North American carriers, and KLM in Europe and asked them to give us a chance on the DC-10,” the late Brian Rowe, CF6 manager at the time, wrote in his autobiography. “We had a good engine design and we promised to give them first-class product support.”
Lockheed launched its L-1011 with Rolls-Royce, whose engine development struggles led to bankruptcy. Meanwhile, P&W had its hands full with financial outlays in meeting the challenging Boeing 747 thrust requirements.
For GE to re-enter the airline industry, it was the DC-10 or bust. Adding to the drama, Douglas by 1967 faced financial woes and McDonnell Corporation took over the company, creating McDonnell Douglas. The merger ensured financial stability for the DC-10 and enhanced GE’s chances on the airplane because of a strong relationship from powering McDonnell’s F-4 Phantom.
In a landmark win for GE, United Airlines in June of 1968 launched the CF6-6 engine on the new 252-passenger McDonnell Douglas DC-10. American Airlines soon followed suit.
GE’s tough CJ805 experience remained on the minds of GE leaders. The team redesigned the CF6-6 compressor shaft to handle the high utilization of commercial jetliners. The front fan, similar in diameter to the TF39, was simplified with a lower bypass ratio. Through improved mechanical design, materials, and turbine-cooling technology (forever a GE hallmark), the CF6-6 operated at higher temperatures and brought a new level of efficiency to large turbofans while producing 40,000 pounds of thrust.
What followed was a flurry of new GE engines that changed the commercial engine playing field. In 1969, GE launched the CF6-50 on the new Airbus Industrie A300 and the DC-10-30. The CF6 program created a relationship between GE and the French engine maker Snecma (now Safran Aircraft Engines) that led to the creation of the 50/50 joint company CFM International in 1974 and the CFM56 engine family.
In 1975, GE launched the CF6-50 on the Boeing 747-200. In 1978, the CF6-80A was launched on the A310 and Boeing 767. In 1979, the CFM56-2 won a DC-8 re-engining program, and in 1981, Boeing selected the CFM56-3 for the Boeing 737 Classic series. A year later, Airbus selected the CFM56-5 for the A320.
You get the picture.
By 1988, 20 years after the CF6-6 launch, the growing CF6 and CFM56 engine families were firmly established as annual best sellers in their respective thrust classes across several jetliners models.