WEEK 18
H2F brings you the ‘helicopter mayday of the week’ with a short accident report summary. I tell you what happened. You think more about why it happened. We all learn from it. Because that’s what accident reporting is for.
TITLE
Night departure over water results in spatial disorientation and fatal loss of control.
WHAT?
A private AW139 was conducting a flight from Big Grand Cay, Bahamas, to Florida after transporting passengers to the island earlier that night. Following a brief stop, the helicopter departed with two pilots and five passengers. Shortly after takeoff, the aircraft entered an uncontrolled descent and impacted the water. All seven occupants were fatally injured.
WHERE?
Near Big Grand Cay, Bahamas, shortly after departure from a private helipad on the island.
WHEN?
4 July 2019 at approximately 0153am local time. The NTSB issued its final report in May 2021.
HOW?
Prior to departure from the island, the crew discussed the darkness and the challenges of night operations. The takeoff was conducted over water in dark-night conditions with virtually no external visual references. Shortly after liftoff, the helicopter climbed and accelerated normally before entering a left turn and developing increasing pitch and bank. Flight recorder information and wreckage examination found no evidence of mechanical failure. Investigators concluded that the pilots became spatially disoriented during the departure and lost control of the helicopter.
CONDITIONS?
The mission was initiated late at night after an urgent request to transport two ill passengers to the United States. The private helipad was illuminated by floodlights and the departure was conducted in dark-night conditions over featureless water with little or no horizon, producing a classic “black-hole” environment and both pilots discussed the risk of spatial disorientation. The pilot flying had limited night experience and had never previously flown to the island at night.
OUTCOME?
The helicopter was destroyed after impacting the ocean and subsequently sank in shallow water. Both pilots and all five passengers sustained fatal injuries. Recovery of the wreckage and analysis of the cockpit voice and flight data recorder provided investigators with extensive information regarding the accident sequence.
WHY?
The NTSB determined that the accident resulted from the pilots’ decision to depart into dark-night conditions over featureless water, leading to spatial disorientation and loss of control.
Contributing factors included:
- External pressure created by the desire to rapidly transport two passengers requiring medical care.
- The pilot flying’s lack of experience conducting night operations to and from Big Grand Cay.
- Inadequate crew resource management and insufficient cross-monitoring by the non-flying pilot as the upset developed.
- Limited operational defenses against the known hazards of black-hole departures and night overwater flight.
- Deficiencies in the operator’s training, risk management, and safety processes for managing spatial disorientation hazards.
- Failure of the operator’s safety management practices to adequately recognize and mitigate the risks associated with dark-night departures.
- A regulatory environment under Part 91 that required less oversight and fewer procedural safeguards than commercial helicopter operations.
- Reliance on pilot performance rather than robust organizational and procedural barriers to prevent loss of visual reference.
- The alignment of environmental, operational, organizational, and human factors that progressively eroded safety margins before takeoff.
REFERENCE?
National Transportation Safety Board. (2021). Aircraft accident report: Agusta AW139, N32CC, near Big Grand Cay, Abaco, Bahamas, 4 July 2019 (ERA19FA210). National Transportation Safety Board. https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99766/pdf
Note:
Accident reports selected from the following open source databases: US NTSB; UK AAIB; Flight Safety Foundation’s Aviation Safety Network; Australia’s ATSB. Ireland’s AAIU; Taiwan’s TTSB; France’s BEA; Spain’s CIAIAC. Germany’s BFU.
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