Accident Summary
On a charter flight from Resolute Bay to Cambridge Bay, Nunavut, operated under instrument flight rules, a Summit Air Charters Dornier 228-202 was on final approach to Runway 31 True. At 0143 mountain standard time, the aircraft collided with the ground approximately 1.5 nautical miles from the runway threshold. The aircraft was substantially damaged. Two persons (out of two pilots and twelve passengers on board) received serious injuries. The emergency locator transmitter activated, and the crew notified the Cambridge Bay Airport radio operator via the aircraft radio. Local ground search efforts located the aircraft within 30 minutes, and all occupants were evacuated from the site within two hours.
Investigation Findings
Findings as to Causes and Contributing Factors: 1. An abbreviated visual approach was conducted at night in instrument meteorological conditions, which resulted in the flight crew’s inability to obtain sufficient visual reference to judge their height above the ground. 2. The flight crew did not monitor pressure altimeter readings or reference the minimum altitude requirements in relation to aircraft position on the approach, resulting in controlled flight into terrain. 3. The pilots had not received training and performance checks for the installed global positioning system (GPS) equipment and were not fully competent in its use. Attempts at adjusting the settings likely distracted the pilots from maintaining the required track and ground clearance during the final approach.
Findings as to Risk: 1. The precision approach path indicator systems (PAPI) at Cambridge Bay had not been inspected in accordance with the Airport Safety Program Manual. Although calibration did not have a bearing on this occurrence, there was increased risk of aircraft misalignment from the proper glide path, especially during night and reduced visibility. 2. The flight crew’s cross-check of barometric altimeter performance was insufficient to detect which instrument was inaccurate; reference was made to a defective altimeter, increasing the risk of controlled flight into terrain. 3. Operators’ maintenance organizations typically lack access to troubleshooting information in Component Maintenance Instruction Manuals for Intercontinental Dynamics Corporation altimeters, potentially allowing dispatch of damaged instruments with risk of calibration loss during flight. 4. The flight occurred during a period when the crew’s circadian rhythm cycle could degrade cognitive and physical performance unless recognized and managed.