History of Flight
The Robinson R44 helicopter, registration C-FOBX and serial number 0890, operated by Sarvair Aviation Ltd., departed Grande Prairie, Alberta, at 1600 MST for Grande Cache, Alberta. The aircraft carried one pilot and one passenger. The helicopter was certified, equipped, and maintained in accordance with existing regulations, with no known deficiencies before the flight. Weight and center of gravity were within limits, and sufficient fuel was onboard.
Prior to departure, the pilot conducted a safety briefing for the passenger, a company employee and designated safety briefer for logging operations. The pilot carried a SPOT satellite GPS messenger but was unaware he had subscribed to its 911 function; neither occupant was familiar with activating the device's functions.
Accident Sequence
During the flight, the helicopter encountered precipitation along an approaching cold front and altered course south to parallel the weather edge. While approaching Grande Cache, the flight was near snow associated with the front. At approximately 1702 MST, while climbing over rising terrain, the helicopter lost engine power and main rotor rpm. The pilot turned downhill to regain rotor speed; when unsuccessful, he executed a forced landing into trees, where the aircraft came to rest on its right side.
The pilot was seriously injured when the passenger fell on top of him during impact; the passenger sustained no injury.
The engine, an Avco Lycoming O-540-F1B5, experienced performance degradation to the point that a forced landing was unavoidable. Weather conditions were conducive to carburetor icing; the pilot, who had primarily flown turbine-powered helicopters, was less familiar with carburetor ice. The carburetor heat lever could move from the required position via collective arm movement. The loss of power was likely due to carburetor icing that could not be corrected in time.
Search and Rescue
The emergency locator transmitter (ELT) did not activate during impact, delaying search and rescue (SAR) response. The ELT had a fully charged battery, but a loose connector between the battery and transmitter prevented transmission until the unit was struck against a tree at 2041 MST, when contact was made. The ELT's unidirectional axis gravity switch likely would not have triggered due to impact orientation. The delayed activation contributed to the extended rescue time.
The passenger activated various SPOT functions, but unfamiliarity with the device and uncertainty among family members during discussions with the Joint Rescue Coordination Centre (JRCC) further delayed response. Multiple SAR agencies used different geo-referencing formats, requiring conversions that led to location variances and delays. The lack of a common communication frequency among responders also hindered coordination.
The passenger eventually walked to a road and led SAR resources to the injured pilot more than 11 hours after the accident. The STARS aircraft landed within half a nautical mile of the site, but its crew was not trained for ground rescue. No primary SAR helicopter was tasked, and no secondary was available until the following day. The occupants spent over 15 hours at the site before rescue.
Findings
The Transportation Safety Board of Canada determined that carburetor ice likely caused the loss of engine power and main rotor rpm. Contributing factors included: the loose ELT connector, the unidirectional gravity switch, differing geo-referencing formats among SAR agencies, lack of a common communication frequency, and unfamiliarity with the SPOT device. No SAR level of service metric existed for Canadian Forces coverage.
Safety Actions
Following the occurrence, the TSB issued Aviation Information Letter A09W0021-D1-L1 on passenger safety briefings and alternate means of emergency location. STARS changed its standard operating procedures to mandate the DD MM.mm latitude/longitude format. JRCC Trenton increased vigilance to minimize geo-referencing inaccuracies. The National Search and Rescue Secretariat initiated research into a common geo-referencing standard. Sarvair Aviation continued carrying SPOT units, added website codes and passwords to its overdue aircraft checklist, and began creating a SPOT basic use information card.