Engine upgrades include a new pylon to secure GE CF6 commercial engines to the wing, replacing the current 42,000-lb thrust engines. The CF-6 has been in service on the 747 for a number of years and will be downrated from 60,000-lbs of thrust to 50,000-lbs because the C-5 can't handle that much power. The new engines dramatically improve performance. The C-5's cruise ceiling will increase from 24,000 feet to 33,000 feet and provide 22 percent greater takeoff thrust, 30 percent less takeoff distance, and 58 percent less time to climb than with the C-5's current TF39 engines. The new engines also meet Stage 3 civilian noise standards, the quietest category.
Cost for the new avionics is pegged at $3.5 million a plane, while the new engines will cost $65 million. The upgrades are expected to help keep the aircraft in service through 2040. In 1998 manufacturer Lockheed Martin said the airframes had around 80 percent service life left in them, with the old avionics and engines providing the most service problems. Doug Mohney
The U.S. Air Force's 112 C-5 transports are being upgraded with modern avionics and new engines over the next four years. Each C-5 will get seven LCD displays to replace existing displays and lots of older analog boxes that were last updated in the 1980s. Avionics upgrades include the ability to electronically upload flight plans into the system, a satellite communications capability, and a high-frequency data link. The new avionics package puts the C-5 into compliance with FAA and International Civilian Aviation Organization air traffic management standards. Other enhancements include a better ground proximity warning system, traffic alert and collision avoidance system and a combination GPS/inertial navigation system.