The pilot’s decision to continue a night VFR charter into instrument meteorological conditions (IMC) led to spatial disorientation and a fatal crash near Halloran Springs, California, according to the NTSB’s final report on the Feb. 9, 2024 accident involving an Airbus Helicopters EC130. All six occupants, including two pilots and four passengers, were killed.
Operated by Orbic Air under Part 135, the helicopter departed Palm Springs International Airport (KPSP) at 8:45 p.m. local time. About 80 minutes later, it struck mountainous desert terrain in dark conditions with low visibility, rain, and snow.
A required radar altimeter was known to be inoperative before the accident. The company president, who was also the flight follower, indicated he “told the pilot that the flight could not depart if the radar altimeter was not functioning,” the report states. “A company mechanic performed some troubleshooting on the radar altimeter; however, he was unable to rectify the issue, and the radar altimeter remained non-functional. The mechanic reported that the pilots and the [director of maintenance] were aware that the radar altimeter was not functioning,” but departed on a positioning flight anyway.
The positioning flight landed approximately 40 minutes later to pick up charter passengers at KPSP, and the subsequent charter flight takeoff was delayed due to one passenger forgetting a passport, the report said. During that time, “there was no record that the pilot or safety pilot obtained a formal preflight weather briefing for the accident flight,” the report stated, and “there was no evidence that the pilot updated the FRA [flight risk assessment] after his initial assessment.”
However, the report notes that “the National Weather Service issued weather updates involving the planned flight route area. The updates included lower ceilings and precipitation with rain and snow showers across the region.”
The accident flight launched under night VFR with “no moon illumination” and was intended to follow illuminated freeways to Boulder City Municipal Airport (KBVU) in Boulder City, Nevada. But terrain surrounded the route, the weather deteriorated, and visibility dropped.
ADS-B data showed that “about 10 miles west of the accident site, with mainly freeway vehicle lights available, the pilot began operating the helicopter at lower and slower airspeeds, deviated to the north of the freeway about 3,100 feet laterally, then returned back over the freeway. The lower altitude, slower airspeed, and deviation were likely due to encountering low ceilings and reduced visibility related to precipitation. Generally, helicopter pilots are trained to slow down and descend, if prudent, when negotiating or encountering deteriorating weather conditions. This can allow a pilot more time to safely maneuver the helicopter to avoid the conditions. The accident site area included hilly terrain that was rising on both sides of the freeway and in front of the helicopter.”
After this, the rotorcraft’s airspeed and altitude increased before beginning a right turn, which was maintained for about 10 seconds while in a rapid descent. The helicopter crashed into terrain while in the turn.
Post-crash inspection revealed no mechanical failure. “The engine displayed rotational damage signatures and resolidified metal deposits consistent with powered operation at impact,” the report noted.
Although the pilot had received training in inadvertent IMC recovery, the response deviated from that training. “The gradual right turn, increased airspeed, and increased descent rate were inconsistent with the training to recover from entry into IMC,” the NTSB found. It also cited spatial disorientation, likely exacerbated by vestibular illusions such as the Coriolis and somatogravic (false climb sensation) effects.
The NTSB cited not only pilot error but also organizational failure. “Company management...failed to exercise ground and flight operational control to cancel or modify the flight,” the report noted. Additionally, “there was no evidence the pilot updated the FRA after his initial assessment,” even as weather conditions deteriorated and the flight experienced delays.
Despite being identified prior to departure, the radar altimeter issue was never logged. “The inoperative radar altimeter was not entered into the aircraft maintenance log as required by the company’s general operations manual,” investigators wrote.