Honeywell is making the HGT 1700 auxiliary power unit (APU) for the A350, which is the largest APU the manufacturer has produced.
Honeywell has worked in close collaboration with Airbus from the A350’s design concept phase so that the APU, which will drive the aircraft’s environmental system, would meet the A350’s efficiency and comfort targets.
Honeywell developed its A350 Air System Integration Bench, or AirSIB, so that the APU could be developed from the start as an integrated system that was de-risked.
The AirSIB includes a full engine so that bleed air—required for APU operations—was accurately replicated in development and testing. This was the first time Honeywell has taken this approach to APU development.
Based on the article "Airbus readies for fifth A350 to fly; remains committed to -800 variant" published in ATW.