What aircraft was involved and where did it happen?

The accident on 2009-05-04 involved a Cessna 150L C-GJAE, operated by Air Richelieu 1990, at Saint-Louis, Quebec, CA.

What was the probable cause of the accident?

The collision was caused by the aircraft flying at a low altitude, which resulted in an impact with an unmarked telephone cable spanning the Yamaska River.

Two fatalities in Cessna 150 collision with telephone cable

A training flight over the Yamaska River ended in tragedy when a Cessna 150L struck an unmarked telephone cable, resulting in two deaths.

What happened

On May 4, 2009, an Air Richelieu Cessna 150L, registered C-GJAE, departed Montréal/Saint-Hubert Airport for a scheduled flight training session. The flight, involving an instructor and a student pilot, was intended to cover basic maneuvers including straight and level flight, climbs, and descents. After completing the initial portion of the lesson, the aircraft traveled toward a training area northeast of the airport.

While flying at a very low altitude over the Yamaska River in Quebec, the aircraft encountered a telephone cable that spanned the river from west to east. The aircraft struck the cable while in a 3-degree bank, causing it to impact the water's surface in a nose-down attitude. The aircraft sank quickly following the impact. The flight instructor was fatally injured at the scene, and although the student pilot managed to exit the wreckage, they subsequently drowned. The aircraft sustained substantial damage.

The investigation

Investigators examined the wreckage and analyzed radar data, which showed the aircraft flying at approximately 200 feet above ground level before descending below 100 feet over the river. The investigation confirmed that the engine and flight controls were functioning normally at the time of the collision, suggesting the pilot was not managing an in-flight emergency.

Because the aircraft's GPS had been turned off prior to departure, precise flight path details below the radar floor could not be determined. The investigation also noted that the telephone poles on either side of the river were obscured by trees and brush, making the presence of the cable difficult to detect. The cable itself was unmarked, as it was not officially classified as an aeronautical or navigable waters hazard.

Findings

The aircraft was operated at a low altitude, which led to the collision with the unmarked telephone cable.

The flight instructor deviated from the established training program and company procedures by flying at such a low level, as the planned exercises did not require altitudes below 500 feet.

The lack of visibility of the cable was exacerbated by the fact that the supporting poles were hidden by vegetation and the cable lacked any identifying markers.

Safety action

Following reports of low-level flying in the area after the accident, the cable owner, Télébec, installed red and white markers on the cable spanning the Yamaska River to increase visibility.