CFM56-2 performance upgrades yielding results for USAF

The U.S. Air Force (USAF) is now operating the first of a planned fleet of 1,440 CFM56-2 engines (military designation F108) upgraded as part of the CFM Performance Upgrade Program (C-PUP). The engines power the USAF fleet of KC-135R Stratotanker aircraft and the program is expected to be completed over the next 12 years. In addition, the U.S. Navy has also ordered upgrades for 75 engines in its E-6B Mercury aircraft fleet. The C-PUP configuration incorporates new high-pressure compressor airfoils designed using three-dimensional aerodynamic techniques to improve engine efficiency. As a result, the upgrade will provide a 1.5% improvement in engine specific fuel consumption, which equates to as much as 3.8m gallons of fleet fuel burn reduction by the end of the fifth year at projected upgrade rates. In addition, new high-pressure turbine hardware that incorporates the latest materials technology will extend engine life by improving the EGT (exhaust gas temperature) margin by 15 degrees Celsius. Every degree of EGT margin equates to 1,000 more hours on wing.