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Cases › ANC12FA084 · Part 135 fatal

MCDONNELL DOUGLAS HELICOPTER 600NAurora Aviation Services Inc.

Delta Junction, AK, USA · 2012-08-08·N737TV

1
fatal
0
serious
Fatal
highest injury
Substantial
damage
AnalyseThe analystOne timeline · precedents · ask the docket · what the record saysGenerateInvestigation briefFacts, cause, recorder extremes, sequence, sourcesSourceNTSB docket8 documents on data.ntsb.gov

What happened

NTSB summary, verbatim

The pilot was transporting personnel from a remote elevated helipad constructed of logs. Witnesses stated that the helicopter had just touched down, and the pilot turned his head to give the signal to board when the helicopter suddenly pitched up and back, striking trees at the edge of the helipad. The helicopter rolled down the hill. A postaccident examination of the helipad revealed that one of the logs that made up the rear portion of the helipad decking had been pulled from the structure and damaged. Based on the lack of mechanical anomalies with the helicopter and the damage to the helipad decking, it is likely the pilot landed too far forward on the helipad, which allowed the tail of the left skid to fall into the open area between the logs and become entangled. It is likely that the pilot sensed the imbalance and applied collective pitch, which resulted in a dynamic rollover.

Photographs

2the aircraft, and what the investigators found
Wreckage and site documentation · 2 photographs from the docket

Photographs are NTSB docket attachments — works of the US government, in the public domain. Captions are the Board’s own.

Probable cause

the Board's determination
The pilot’s failure to clear the left landing gear skid, which resulted in the entanglement of the left landing gear skid with a log, and his subsequent application of collective pitch, which resulted in a dynamic rollover.

Occurrence sequence

2 stepsNTSB coding · CICTT taxonomy
  1. 1 · Landing-aborted after touchdown
    Dynamic rollover
    defining event
  2. 2 · Landing-aborted after touchdown
    Collision with terr/obj (non-CFIT)

Findings

2 causal · 1 contributing
  • CAUSE
    Personnel issues › Task performance › Use of equip/info › Aircraft control — Pilot
  • CAUSE
    Personnel issues › Action/decision › Info processing/decision › Decision making/judgment — Pilot
  • FACTOR
    Aircraft › Aircraft oper/perf/capability › Performance/control parameters — Capability exceeded

NTSB analysis

from the final report

The pilot was transporting personnel from a remote elevated helipad constructed of logs. Witnesses stated that the helicopter had just touched down, and the pilot turned his head to give the signal to board when the helicopter suddenly pitched up and back, striking trees at the edge of the helipad. The helicopter rolled down the hill. A postaccident examination of the helipad revealed that one of the logs that made up the rear portion of the helipad decking had been pulled from the structure and damaged. Based on the lack of mechanical anomalies with the helicopter and the damage to the helipad decking, it is likely the pilot landed too far forward on the helipad, which allowed the tail of the left skid to fall into the open area between the logs and become entangled. It is likely that the pilot sensed the imbalance and applied collective pitch, which resulted in a dynamic rollover.