10 Nov 2011: EUROCOPTER EC 130 B4 (N11QV) — Blue Hawaiian Helicopters — Pukoo, HI

5 fatalitiesPukoo, HI, United States

A commercial sightseeing flight ended in a fatal crash after a Eurocopter EC130 B4 struck mountainous terrain on the island of Molokai.

What happened

On November 10, 2011, a Eurocopter EC130 B4 helicopter, registration N11QV, crashed into mountainous terrain near Pukoo, Hawaii. The flight was a scheduled sightseeing tour operated by Blue Hawaiian Helicopters, traveling from Kahului Airport on Maui to the island of Molokai. The flight was conducted under visual flight rules (VFR).

At the time of the accident, the aircraft was flying near the southern side of Molokai. While the departure airport experienced visual meteorological conditions, the area around the accident site was experiencing heavy rain squalls, high winds, and low cloud bases. Witnesses on the ground reported hearing a "whoop whopping" sound and observing the helicopter descending from a ridgeline. One witness described the aircraft going "straight down" before impacting the ground, which resulted in a large fireball.

The crash resulted in 5 fatal injuries, involving the pilot and four passengers.

The investigation

Investigators examined the wreckage, which spanned a debris field of approximately 1,330 feet. The main wreckage rested inverted on a north-south oriented ridgeline. The investigation focused on the separation of the Fenestron (the shrouded tail rotor) from the tail boom.

Detailed examination of the Fenestron revealed three distinct cuts through the lower portion of the structure. These cuts were consistent with the main rotor blades striking the lower Fenestron at least three times on the left side. The investigation also found that the forward flange of the junction frame had fractured. Additionally, the right side of the horizontal stabilizer had experienced significant damage, with attachment fittings sheared due to upward and aft loading.

Engine examination of the Turbomeaster Arriel 2B1 engine showed no evidence of mechanical malfunctions or failures that would have prevented normal operation.

Probable cause

The pilot failed to maintain sufficient clearance from mountainous terrain while flying in marginal weather conditions. This led to the horizontal stabilizer and the lower forward portion of the Fenestron striking vegetation or terrain, causing the Fenestron to separate from the tail boom and resulting in a loss of control. The pilot's decision to fly into an area with rising terrain, low cloud bases, rain showers, and high winds also contributed to the accident.

Contributing factors

Altitude — Not attained/maintainedContributed to outcomeDamaged/degradedCapability exceededPilot