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.
Occurrence summary
| Investigation number | AO-2009-078 |
|---|---|
| Occurrence date | 15/12/2009 |
| Location | 296 km NE of Perth Airport |
| State | Western Australia |
| Report release date | 20/04/2010 |
| Report status | Final |
| Investigation level | Short |
| Investigation type | Occurrence Investigation |
| Investigation status | Completed |
| Mode of transport | Aviation |
| Aviation occurrence category | Diversion/return |
| Occurrence class | Serious Incident |
| Highest injury level | None |
Aircraft details
| Manufacturer | De Havilland Canada/De Havilland Aircraft of Canada |
|---|---|
| Model | DHC-8 |
| Registration | VH-XFU |
| Serial number | 151 |
| Sector | Turboprop |
| Operation type | Charter |
| Departure point | Perth, WA |
| Destination | Darlot, WA |
| Damage | Nil |