Sikorsky S-76B accident at Calabasas, California, 26 Jan 2020 (N72EX)

Accident narrative

On January 26, 2020, about 0946 Pacific standard time, a Sikorsky S-76B helicopter, registration N72EX, entered a rapidly descending left turn and crashed into terrain in Calabasas, California. The pilot and eight passengers died, and the helicopter was destroyed. The flight was operated by Island Express Helicopters Inc. as a Title 14 Code of Federal Regulations Part 135 on-demand passenger flight under visual flight rules (VFR).

**The flight**

The flight departed from John Wayne Airport-Orange County in Santa Ana, California, about 0907, destined for Camarillo Airport in Camarillo, California, about 24 miles west of the accident site.

The 50-year-old pilot held a commercial pilot certificate with rotorcraft-helicopter and instrument ratings. He had about 8,577 hours of flying experience, including about 1,250 hours in Sikorsky S-76-series helicopters and about 75 hours of instrument flying time. He was the company's chief pilot and had flown the client who was aboard the accident flight 10 times between Santa Ana and Camarillo in the last year, including the day before the accident.

Before the flight, the pilot completed a flight risk analysis form at 0657, scoring the flight in the company's low-risk category. He noted a cloud ceiling of less than 2,000 feet above ground level. He did not update the form before departure, although updated weather information was available. The pilot discussed the weather with the air charter broker before departure, stating he planned to go "up and around" the weather by flying north and east around downtown Los Angeles, Burbank, and Van Nuys.

**Sequence of events**

After departing Santa Ana, the helicopter flew northwest at altitudes below 1,700 feet mean sea level (msl) and generally between 400 and 600 feet above ground level (agl). At 0920, the pilot contacted the Bob Hope Airport (Burbank) air traffic control tower to request a special visual flight rules (SVFR) clearance through the airspace. The controller advised the pilot to hold outside the airspace due to traffic and reported that the last reported cloud tops were at 2,400 feet msl.

At 0932, the controller cleared the flight through the Burbank airspace, advising the pilot of 2.5 miles visibility, haze, and an overcast ceiling at 1,100 feet agl. The pilot subsequently requested and received an SVFR transition through the Van Nuys airspace.

At 0940, the pilot contacted the Southern California terminal radar approach control (SCT) facility, advising that the flight was transitioning in "VFR conditions" at 1,500 feet msl to Camarillo at a "low altitude." The controller advised that radar and radio contact would likely soon be lost and instructed the pilot to squawk a VFR transponder code.

At 0942, the helicopter reached US Route 101 and began following it west at an altitude of about 1,420 feet msl (550 feet agl) and a groundspeed of about 140 knots. At 0944:34, the pilot announced on the SCT frequency that he was starting a climb to "go above the, uh, layers." The helicopter immediately began climbing at a rate of about 1,500 feet per minute and began a gradual left turn while generally remaining over US Route 101. A new SCT controller asked the pilot to "ident" his transponder and asked if he was requesting flight following, to which the pilot replied, "yes sir."

About 0945:10, the climbing helicopter started a left turn away from US Route 101. It reached a maximum altitude of about 2,370 feet msl (1,600 feet agl) at 0945:15 before it began to descend rapidly while remaining in the left turn. At 0945:17, the controller asked the pilot his intentions. The pilot replied that the flight was climbing to 4,000 feet msl. The controller received no further communication. The helicopter crashed into hilly terrain at an elevation of about 1,100 feet msl.

**What the investigation found**

The wreckage was located on 36-degree sloping terrain. Postaccident examination of the airframe, flight controls, rotor systems, and instruments identified no evidence of preimpact malfunction or failure. Both engines displayed rotational damage signatures consistent with powered operation at impact. Toxicology testing on the pilot was negative for alcohol and other tested-for substances, and the investigation found no evidence of pilot fatigue or medical impairment. The helicopter was not equipped with a crash-resistant flight recorder system, nor was it required to be.

The Board determined that an unusually thick marine layer was present across the region. Weather data, camera images, and witness reports indicated that cloud bases near the accident site were between 1,300 and 1,400 feet msl, with visibility beneath the clouds estimated between 1 and 1.5 miles. The Board concluded that at the time the pilot initiated the climb, the helicopter had already begun penetrating clouds, and the pilot lost visual reference to the horizon and the ground.

The investigation found that the pilot's decision to fly at an excessive airspeed of 140 knots for the weather conditions was inconsistent with his adverse-weather-avoidance training and reduced the time available to avoid entering instrument meteorological conditions (IMC).

The Board concluded that the pilot experienced spatial disorientation while climbing in IMC, leading to a loss of control. The steady left turn was conducive to a vestibular illusion called the "leans," in which the pilot would incorrectly perceive that the helicopter was flying straight and level. Furthermore, as the helicopter began to rapidly descend and accelerate in a steep left bank, it created conditions conducive to a somatogravic illusion, in which the pilot would incorrectly perceive that the helicopter was climbing. The pilot's radio transmission that he was climbing to 4,000 feet while the helicopter was actually descending rapidly demonstrated his lack of awareness of the helicopter's actual flight profile.

The investigation found no evidence that Island Express, the air charter broker, or the client pressured the pilot to complete the flight. However, the Board found that the pilot's decision to continue into deteriorating weather was likely influenced by self-induced pressure to fulfill the client's travel needs, his lack of an alternative plan, and plan continuation bias, which strengthened as the flight neared its destination.

The Board also reviewed the company's safety management system (SMS). Although Island Express had an SMS, it was not required by the FAA and was not fully implemented. The Board found that the company's lack of a documented policy and safety assurance evaluations to ensure pilots were consistently and correctly completing flight risk analysis forms hindered the form's effectiveness as a risk management tool. Had the pilot completed an updated form before departure, the weather conditions would have required him to seek input from the director of operations and provide an alternative plan.

Finally, the Board noted that the air traffic controller's failure to report the loss of radar contact and radio communication as an emergency was inconsistent with procedures, but this deficiency did not contribute to the accident or affect its survivability.

**Probable cause**

The National Transportation Safety Board determined that the probable cause of this accident was the pilot’s decision to continue flight under visual flight rules into instrument meteorological conditions, which resulted in the pilot’s spatial disorientation and loss of control. Contributing to the accident was the pilot’s likely self-induced pressure and the pilot’s plan continuation bias, which adversely affected his decision-making, and Island Express Helicopters Inc.’s inadequate review and oversight of its safety management processes.