Testing Shows New APU Reduces Fuel Burn By Up To 10 Percent

Honeywell announced Thursday that it has completed the initial ground tests for the Auxiliary Power Unit (APU) on the Airbus A350 XWB aircraft.

"Our HGT1700 APU features technological advances to increase safety and operability while integrating the APU and air management systems, giving Airbus a more efficient system," said Justin Ryan, vice president, Airbus, at Honeywell Aerospace. "This contract represents a new way of working together. Honeywell involvement began early in the aircraft design cycle, providing more systems integration and subcontracts management across a broader set of equipment than in previous contracts, which delivers efficiencies to Airbus and benefits to the A350 XWB operator."

The HGT1700 passed its First Engine To Test (FETT) milestone in October, on schedule.

The HGT1700, at 1700 shaft horsepower (SHP), is the largest APU Honeywell has ever developed. An APU is a gas-powered turbine engine that provides bleed air for main engine starting and pneumatic and electrical power for cockpit and galley systems. The new APU incorporates proven technology from Honeywell 331-500/-600 APUs, including technologies that have more than 14 million hours of service. The system's core reliability is proven in a design with more than 14,000 hours.

Artist's Concept

Unlike predecessor APUs, the HGT1700 features variable speed during ground operation which reduces fuel burn by up to 10 percent, a new hydraulic bleed valve for improved reliability, an improved combustor to reduce clogging and improve field durability, and new materials to reduce weight. The engine weighs less but provides more power, allowing it a 13 percent power-to-weight improvement over 331-500/-600 APUs. A starter generator system is designed into the new APU, saving weight and simplifying design while providing electrical power for the aircraft's system at altitudes of up to 43,100 feet.

FMI: www.honeywell.com