NAVAIR's Decision to Not Provide Updated Power Charts for the CH-46E's ERIP is Prematurely Aging the Assault Support Fleet
MARINE CORPS COMMAND AND STAFF COLL QUANTICO VA
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The CH-46E Sea Knight is a Vietnam-era helicopter, the oldest helicopter in combat use in the military. The primary mission of the CH-46E is to rapidly disperse combat troops, support equipment, and supplies from amphibious assault landing ships and established airfields to advanced bases in underdeveloped areas under all-weather conditions in day or night. The Sea Knights engines have become old and deteriorated, reducing the aircrafts combat effectiveness. Through the Engine Reliability Improvement Program ERIP, NAVAIR contracted with General Electric GE to recapture lost performance from the GE-T58-16 -16 engines. The first improved engines GE-T58-16A entered the fleet in fiscal year 2003. The contract did not require GE to guarantee original engine performance nor did it require GE to produce new power charts. Although the -16A engines produce power near or above original -16 specifications, the lack of new power charts prevents any recuperation of lift capabilities for the Marine Corps most prolific and heavily flown helicopter. Power charts guarantee minimum engine power available, given predicted in-flight temperature and air pressure. Once the weight of crew, fuel, and weapons and ammunition are subtracted from the computed lift capability, the remaining weight becomes available for payload. When the aircraft operates at higher altitudes and temperatures, as experienced in Afghanistan, lift capability decreases beginning around 4,000 feet and 25 degrees C. The aircraft still requires 2600 pounds of fuel, so the maximum payload of 3400 pounds is reduced. The CH-46Es engine power charts must be revised to incorporate the aircrafts newly modified engine power. Every flight by the CH-46E with the modified engines in high or hot environments without new power charts wastes flight hours. The additional hours reduce the time until each aircraft reaches its service life.
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