What happened
On a flight from Montréal/Pierre Elliott Trudeau International Airport to Montréal/St-Hubert Airport, a Beechcraft King Air 100, registration C-GJLP, experienced a series of cascading system failures immediately following takeoff. While performing line-up checks, the pilot-in-command mistakenly moved the engine start and ignition switches instead of the auto-ignition switches. This error caused the aircraft's electrical load to be supported solely by the battery.
Shortly after departure, the aircraft's landing gear failed to retract properly. As the crew addressed the gear indication, the aircraft suffered a loss of radio communication, radio navigation equipment, and several flight instruments. Due to the loss of IFR capabilities and the inability to communicate with air traffic control, the crew decided to descend from their assigned altitude to regain visual contact with the ground. The aircraft eventually landed at Montréal/St-Hubert Airport without further incident, and there were no injuries or damage to the aircraft.
The investigation
The investigation focused on the sequence of switch manipulations and the subsequent electrical depletion. Investigators examined the cockpit switch configuration, noting that the ignition and engine start switches were left in a position that prevented the generators from coming online. The investigation also reviewed the crew's use of checklists, specifically the "Abnormal gear indication" procedure, and how the focus on the landing gear may have diverted attention from the underlying electrical issue.
Findings
- The primary cause of the electrical failure was the pilot-in-command inadvertently selecting the ignition and engine start switches instead of the auto-ignition switches prior to takeoff.
- The line-up checklist did not include a requirement to check the load indicator, which would have confirmed the generators were active.
- The aircraft's warning lights did not provide a clear indication that the generators were offline, preventing the crew from identifying the source of the power drain.
- The crew's focus on the landing gear malfunction prevented them from completing the necessary checklists to address the electrical depletion.
- By failing to follow the "landing gear will not retract" checklist, the crew did not cut power to the landing gear motor, which could have preserved battery life for the radios and instruments.
- The decision to descend below the minimum sector altitude without precise positioning increased the risk of terrain collision.