What happened
A Beech King Air C90A, registration C-FGXH, was operating an instrument flight from Winnipeg to Edmonton City Centre Airport via Regina. During the arrival into Edmonton, the crew attempted a localizer back course approach to Runway 16. Upon intercepting the localizer, the aircraft immediately drifted left of the course and descended approximately 400 feet below the required minimum step-down altitude. The flying pilot initiated a missed approach, during which the aircraft's airspeed dropped to 90 knots—near the minimum single-engine control speed—and the crew failed to maintain assigned headings and altitudes.
During the subsequent attempt to rejoin the approach, the aircraft drifted again, and the crew misidentified their position by relying on GPS distance rather than the DME display. This error led to a second descent below the minimum step-down altitude. The aircraft eventually descended below the cloud base, allowing the crew to transition to a visual approach and land safely.
The investigation
The investigation focused on the crew's management of the aircraft's recently installed Electronic Flight Instrument System (EFIS). Investigators determined that the crew had incorrectly configured the course selector on the electronic horizontal situation indicator (EHSI). While the captain's instruments were set correctly, the flying pilot's EHSI was set to an incorrect course, causing the autopilot to steer the aircraft away from the intended track.
Further examination revealed that the crew's reliance on GPS data for distance information contributed to a loss of situational awareness regarding their distance from the airport. The investigation also looked into the pilot's ability to maintain manual control during the missed approach and the adequacy of the operator's transition training for the new avionics.
Findings
- The flight crew lacked sufficient familiarity with the C90A EFIS equipment, leading to improper course settings and flight director modes on three successive approaches.
- The crew used improper EHSI course settings which caused the aircraft to deviate from the localizer track.
- The flying pilot demonstrated an inability to maintain effective manual control during the missed approach, resulting in significant airspeed decay and failure to adhere to air traffic control instructions.
- A reliance on GPS distance readings instead of DME caused the crew to descend below minimum altitudes prematurely.
- Inadequate transition training and a lack of recent flying time on the specific aircraft type contributed to the crew's inability to manage the approach effectively.
- The operator's environment, which discouraged manual flight in favor of autopilot use, contributed to the degradation of the flying pilot's manual handling skills.