What happened
On February 10, 2018, an Airbus Helicopters EC130 B4 helicopter, registration N155GC, was involved in an accident near Peach Springs, Arizona. The aircraft was operating as a Part 136 air tour flight, transporting six passengers to the Quartermaster landing site in the Grand Canyon.
As the pilot approached the landing area from across the Colorado River, he initiated a descending left turn toward the west landing pads. During this maneuver, the pilot encountered a violent gust of wind that caused the aircraft to spin, leading to a loss of directional control. A witness on the ground observed the helicopter decelerate, enter a nose-up pitch, and undergo several oscillations before rotating 360 degrees twice and descending into the terrain. The impact was immediately followed by a postcrash fire.
The accident resulted in 5 fatal injuries and 2 serious injuries. The pilot and one passenger sustained serious injuries, while three passengers died due to burns and smoke inhalation.
The investigation
Investigators examined the wreckage and found that the engine and main rotor components showed no evidence of mechanical failure that would have prevented normal operation. However, the postimpact fire destroyed much of the airframe, including the seats and the fuel system. The aircraft was not equipped with a crash-resistant fuel system.
Meteorological analysis revealed that a cold front was moving through the region, bringing gusty winds and turbulence. While the morning weather briefing provided some information regarding gusty winds, more recent NWS advisories and forecasts indicating significant wind gusts were likely not captured by the pilot. At the landing site, the only available wind indicator was a windsock, which could not communicate the presence of downdrafts or turbulence.
Findings
- The aircraft's flight characteristics—including low airspeed and a high power setting—combined with the relative wind position, created conditions highly conducive to a loss of tail rotor effectiveness (LTE).
- The pilot was performing an approach in gusting, tailwind conditions in an area prone to turbulence and downdrafts.
- The immediate postcrash fire was the primary factor affecting the survival of the occupants.
- The pilot did not recheck the weather between tour flights, relying on information from a morning briefing that did not include the most recent wind advisories.