What happened
A Robinson R44 Raven II helicopter, registered C-GOCM, was performing well-site monitoring duties for an oil company southwest of Fox Creek, Alberta, on the day of the accident. After several routine flights, the aircraft made an unauthorized stop at a roadside security gate. During this period, the pilot was observed displaying signs of intoxication. Following the stop, the pilot and an unauthorized passenger departed the gate at 1735 MST. Shortly after takeoff, the aircraft began flying erratically and broke up in flight over a wooded area. The pilot sustained fatal injuries, and there was no post-crash fire.
The investigation
The investigation focused on the circumstances leading to the in-flight breakup and the failure of the emergency locator transmitter (ELT) to transmit on the correct frequency. Investigators examined the aircraft's flight parameters and found that while the helicopter was within weight and balance limits, it had exceeded its maximum allowable speed. The aircraft was equipped with a Dart bubble window, which limits the never-exceed speed (VNE) to 100 knots; however, GPS data indicated a ground speed that equated to an indicated airspeed of approximately 126 knots just before the breakup.
Furthermore, the investigation looked into the company's flight-following capabilities. It was determined that the pilot had failed to file a flight plan or itinerary, and the flight follower—a newly hired pilot who had not been properly trained—did not notice the satellite tracking notifications. Regarding the ELT, investigators found that the use of Velcro retention straps may have allowed internal damage to the device's crystal oscillator during impact, causing it to transmit on an incorrect frequency.
Findings
- The pilot made flight control inputs while under the influence of alcohol that caused the main rotor blade to strike the cabin, triggering the in-flight breakup.
- The pilot's blood alcohol level was significantly above the legal limit for operating an aircraft.
- The lack of adherence to company flight-following procedures prevented the operator from identifying the aircraft as overdue.
- The use of Velcro-style fasteners for mounting the ELT increased the risk of internal component failure during an impact.