Hamilton Sundstrand, manufacturer of the APS5000 auxiliary power unit (APU) has completed extended twin engine operations (ETOPS) ground tests in preparation for the entry into service of the Boeing 787.

The company calls the testing "an important step in providing ETOPS capabilities for 787s upon initial entry into service".

To date, Hamilton Sundstrand says the APS5000 APU has logged 10,000 operating hours, and has completed 24,000 starts in both its lab and flight test programme.

The APS5000 supplies electrical power on the ground, as well as back-up power in flight.

The 787's 'more electric' systems architecture is driven by the power generated by the APU to start the aircraft's General Electric GEnx-1B or Rolls-Royce Trent 1000 engines.

Rather than a traditional pneumatic bleed air system to spool up the aircraft's engines, electrical power from the APU or ground directly drives a gearbox to initiate the engine start process.

The system provides two 225kVA generators, a 230v alternating current starter generator with variable speed operation, an eductor cooling system, no-break power transfer capability and a 15,000h mean time between overhaul core engine design.

Hamilton Sundstrand adds that the APU starts and operates throughout the aircraft's flight envelope.

Boeing expects to deliver the first 787 to Japan's All Nippon Airways in the fourth quarter.

Source: Air Transport Intelligence news