The CFM56-7 has successfully completed all required engine tests, and the first compliance engines have been delivered to Boeing for installation on the 737-700 for flight tests in early 1997.
The CFM56-7 is produced by CFM International (CFMI), a 50/50 joint company between Snecma (Safran Group) of France and General Electric of the United States.
The engine, which is scheduled to be jointly certified by the U.S. Federal Aviation Administration and the French Direction Gnrale de l'Aviation Civile in late October, has completed more than 1,900 hours of flight and ground testing to date. CFMI will complete certification component tests and continue to conduct endurance and engineering tests in the coming months. Overall, the engine will have accumulated more than 3,600 hours by the time the 737-700 makes its first flight early next year.
Major certification tests included, among others, ingestion tests (water, hail, ice, and bird), engine blade-out, and the 750 "C" cycle and 150-hour block tests. In all areas, the CFM56-7 met or exceeded pre-test predictions.
During the 150-hour block test, which included 20 hours of operation at temperatures above maximum redline, the CFM56-7 exhibited minimal deterioration in both its exhaust gas temperature (EGT) and specific fuel consumption (SFC) margins. In fact, the engine has more than 50( C additional EGT margin relative to the equivalent thrust rating on the CFM56-3C1. This additional EGT margin will translate to a fleet average of about 20 percent more time on-wing, both first run and after shop visits.
The CFM56-7's advanced technology, which includes 3-D aero design, a high efficiency wide chord fan, advanced FADEC (Full Authority Digital Electronic Control) system, and active clearance control, will provide airlines with significant cost benefits. The engine's SFC is about 8 percent lower than that of the CFM56-3 on the current 737. This SFC improvement will result in better aircraft fuel burn. On average, a 1 percent reduction in fuel burn can translate to an annual savings of about $15,000 per aircraft. In addition, the engine's maintenance costs are projected to be 15 percent lower at equivalent thrust than those of the industry leader, the CFM56-3C1.
The first CFM56-7 equipped with CFMI's advanced double annular combustor (DAC) is scheduled to go to test in October 1996. The optional DAC, currently in service on the CFM56-5B engine and offered on the -7, lowers engine NOx emissions by as much as 45 percent compared to the single annular combustor configuration. Scandinavian Air Systems will place the DAC in service on the 737-600 in 1998.
Since the CFM56-7-powered 737 program was launched in 1993, it has become the fastest selling aircraft in history. Total orders now stand at 370 firm aircraft.