Aviation safety investigations & reports
Depressurisation - De Havilland Canada, VH-XFU, 296 km NE of Perth Airport WA, 15 December 2009
AO-2009-078

Summary
On 15 December 2009, a De Havilland Canada DHC-8-102 aircraft, registered VH-XFU, departed Perth, Western Australia (WA) on a charter passenger service to Darlot, WA. While cruising at flight level (FL) 230, the aircraft sustained multiple system failures, followed by a depressurisation. The crew actioned the aircraft depressurisation checklist and commenced an emergency descent. During the descent, a number of system cautions and warnings illuminated. The crew elected to return to Perth and a descent to 8,000 ft was made. Shortly after, the majority of the aircraft's systems returned to normal.
A subsequent engineering investigation was unable to replicate
the system faults. However, it appeared that the number-1 direct
current (DC) generator output was spiking, causing power to the
left DC buses to be repeatedly switched between the number-1
transformer rectifier unit and the left DC generator. This repeated
power switching resulted in some of the aircraft's systems behaving
erratically.
As a precaution, the number-1 generator control unit, number-1 DC
generator and left bus tie relay were replaced.
General details
Date: | 15 December 2009 | Investigation status: | Completed | ||
Time: | 1457 WST | Investigation level: | Short - click for an explanation of investigation levels | ||
Location (show map): | 296 km NE of Perth Airport | ||||
State: | Western Australia | Occurrence type: | Diversion/return | ||
Release date: | 20 April 2010 | Occurrence category: | Serious Incident | ||
Report status: | Final | Highest injury level: | None |
Aircraft details
Aircraft manufacturer | de Havilland Canada | |
---|---|---|
Aircraft model | DHC-8 | |
Aircraft registration | VH-XFU | |
Serial number | 151 | |
Type of operation | Charter | |
Damage to aircraft | Nil |