Sundstrand's Auxiliary Power International (APIC) has cleared the last major tests at the APS 2100 auxiliary power unit (APU) for the Boeing 717-200, and is on track for certification in October 1998.
Three key tests now completed include cold and hot day starts, altitude tests and electromagnetic interference (EMI) evaluation. Cold and hot starts ranged from -54 º C to 54 º C.
Altitude tests, conducted at the US National Test Site in Saugus, California, produced "-very good results. It was very reliable and started at 37,000ft [11,300m] and showed capability of starting up to at least 41,000ft," says APS 2100 programme manager, Jean Pierre Foulon. "We also had very successful EMI tests, with no issues at all with the controllers," he adds.
The tests verified APIC's decision to redesign the 717 APU with a similar "total flow control" fuel supply system to that used on the APS 3200 unit fitted to the Airbus A320 family.
Although the APS 2100 is derived from the 2000 series used in the Boeing 737-300/400/500, changes were made to improve reliability and take advantage of lessons learned from both APUs, says Foulon.
The revised system controls all fuel flow for both starting and the main system start through a single fuel servo mechanism.
Forthcoming trials include vibration tests, which are due to be completed by the end of April.
Source: Flight International
