CH-53K Marks Key APU Light-off Milestone
The Sikorsky CH-5

The Sikorsky CH-53K heavy-lift helicopter program this week achieved “ready to load” condition with the successful light-off of its first auxiliary power unit (APU). The program will be ready to begin formal integration testing early next year.

The Hamilton Sundstrand APU is the secondary power system on the helicopter, providing power to a 45KVA generator and a 58-horsepower hydraulic pump and hydraulic starter, as well as providing bleed air to an environmental control system and main engine start system. It will be used for ground operations, main engine start, and conditions when main electrical power provided by the helicopter’s main generators is lost.