A helicopter that crashed in the suburbs of Broome last weekend, killing two people, had experienced "unusual" in-flight vibrations two days before the incident, investigators say.
Key points:
- Investigators say the helicopter's tail rotor broke apart shortly after take-off
- People who flew the aircraft in the days before the crash had reported "unusual" vibrations
- The ATSB advises R44 pilots who experience unusual vibrations to land as soon as possible
The Robinson R44 crashed on Saturday afternoon shortly after take-off, killing 40-year-old pilot Troy Thomas and a 12-year-old Perth girl.
Mr Thomas's 12-year-old daughter, Mia, and Perth woman Maddison Down, 24, remain in a serious condition in Perth hospitals.
In its latest update, the Australian Transport Safety Bureau (ATSB) said the aircraft's tail assembly had broken apart shortly after take-off.
"The tail rotor gearbox assembly, tail rotor and empennage assembly separated soon after the helicopter lifted off," it said.