The pilot of an Enstrom 280C helicopter was to conduct about 30 joyflights during the afternoon. Each flight was planned to last for about 3 minutes and carry two passengers. The flights commenced at approximately 1330 Eastern Standard Time and were to be finished by last light, which was 1758. The aircraft was refuelled twice during the afternoon, with the helicopter shut down and fuel transferred from jerrycans. The second refuelling was completed at about 1745.
Passengers then boarded the helicopter for the twenty-seventh flight of the afternoon. Witnesses reported that transition from the hover to forward flight appeared normal, and that they had then stopped watching the helicopter. A short time later they heard the sound of impact. The helicopter had struck a tree prior to impacting the ground. The occupants were not injured.
The pilot reported that the helicopter's engine did not appear to gain full power during the transition and climb and that he deliberately did not correct a minor out of balance situation to avoid overpitching the rotor. He assessed that there was sufficient engine power available to clear the trees and continue the flight. The area beyond the trees was clear so that if a problem occurred after he cleared the trees, he could have allowed the helicopter to descend to gain performance and continue the flight. The pilot said that the engine turbo-overboost light did not illuminate as it had done during previous departures.
The air temperature was about 28 degrees C. Witnesses reported that the wind at ground level had been calm during the day. The pilot reported that about 20 minutes before the accident, Archerfield Tower, which was about eight kilometres east of the accident location, reported the surface wind at Archerfield to have been easterly at 12 knots. Throughout the afternoon, movement of the tree tops had indicated a steady wind. However, the pilot said that he did not have an opportunity immediately before the takeoff to confirm the wind strength.
The pilot held a Commercial Pilot (Helicopter) Licence and had accumulated 200 hours total flying experience and 130 hours on the Enstrom.
A comprehensive examination of the engine found nothing that might have prevented it from operating normally.
In line with a normal diurnal wind variations, it is possible that the wind was beginning to die at the time of the accident (dusk). Because of the added fuel, the helicopter's all up weight was higher than for the previous takeoff. Both of these changes, either separately or in combination, would have increased the power required for the helicopter to maintain the previously flown departure profile. The pilot would have needed to adjust the departure path or transition technique to account for the decreased performance available. The investigation was unable to determine if maximum engine power had been achieved.
Because no fault could be found with the engine, it was considered likely that the departure path or transition technique had not been sufficiently adjusted to account for the changed conditions. The pilot's low level of experience and the repetitive nature of the flying may have also been factors in the accident.
|Date:||11 April 2001||Investigation status:||Completed|
|Time:||1745 hours EST|
|Location:||8 km WSW Archerfield, Aero.|
|State:||Queensland||Occurrence type:||Collision with terrain|
|Release date:||11 February 2002||Occurrence category:||Accident|
|Report status:||Final||Highest injury level:||None|
|Aircraft manufacturer||The Enstrom Helicopter Corporation|
|Type of operation||Charter|
|Damage to aircraft||Substantial|
|Departure point||Basil Stafford Centre, QLD|
|Departure time||1745 hours EST|
|Destination||Basil Stafford Centre, QLD|
|Role||Class of licence||Hours on type||Hours total|