What happened
On a night flight from Lourdes-de-Blanc-Sablon, Quebec, to Havre-Saint-Pierre, Quebec, a Cessna 402B carrying mail crashed approximately 1.5 nautical miles from the runway threshold. The pilot, the sole occupant of the aircraft, began a descent at 25 nautical miles from the destination. At that time, the pilot received a weather report from the Sept-Îles Flight Service Station indicating visual meteorological conditions (VMC). However, as the aircraft descended, it encountered snow showers and moderate turbulence.
During the approach to runway 2 and the back course, the pilot attempted to manage radio communications to obtain updated weather information. While attempting to maintain control and communicate with the company, the aircraft banked and eventually struck trees and ground before sliding on its belly. The pilot survived with minor injuries, but the aircraft suffered substantial damage.
The investigation
The investigation focused on the discrepancy between the weather information received by the pilot and the actual conditions at the airport. It was established that a technical glitch in the CODCON central computer at Dorval caused a three-hour delay in transmitting weather data from the Havre-Saint-Pierre AWOS station. Consequently, the pilot was operating based on a weather report that was several hours old and did not reflect the incoming snow.
Investigators also examined the pilot's workload and preparation. The pilot was flying alone in darkness and turbulence, which increased the complexity of the instrument approach. The investigation found that the pilot had not prepared for a transition to instrument meteorological conditions (IMC) or a potential missed approach, as he expected to maintain visual contact with the ground.
Findings
- A software error in the Environment Canada central computer delayed the transmission of updated weather observations for approximately three hours.
- The pilot was not mentally prepared to execute an instrument approach in IMC or a missed approach if visual references were lost.
- Increased workload from managing radio communications, turbulence, and flight controls led to less attentive monitoring of the altimeter.
- The pilot continued the descent below the MDA without the required visual references.