What happened
On August 8, 2020, a CANADAIR CL-215-1A10, registration EC-HET, was engaged in aerial firefighting operations near the Lindoso reservoir, spanning the border between Ourense, Spain, and Vila Real, Portugal. The aircraft, operated by BABCOCK Portugal, was part of a coordinated effort to combat a forest fire in the Gerês-Xurés biosphere reserve.
After participating in a water-loading carousel, the crew received instructions from the Portuguese fire coordinator to shift their water drops to a location further south. While maneuvering to this new target, the aircraft entered a narrow valley with a very steep slope. The crew attempted to climb the terrain but ultimately struck the mountainside approximately 150 meters before reaching the crest.
The impact first struck the tail assembly, causing it to break away. Due to the aircraft's keel-shaped lower fuselage, the remaining airframe pivoted forward upon hitting the ground, causing the cockpit to strike the terrain and undergo significant structural deformation. The collision ignited a small fire around the wreckage. The commander managed to exit the aircraft and pull the injured co-pilot to safety, where they were assisted by a firefighting brigade arriving via helicopter. The co-pilot passed away approximately one hour after the accident, while the commander was airlifted to a hospital in Portugal in serious condition.
The investigation
The CIAIAC investigation examined the flight sequence, meteorological conditions, and the aircraft's performance during the climb. Investigators analyzed the aircraft's configuration, noting that the crew had flaps deployed at 10 degrees and later fully extended them before impact. The investigation also reviewed the flight path through the narrow valley and the impact dynamics, specifically how the loss of the tail assembly and the hull shape contributed to the cockpit's destruction.
Findings
- The primary cause of the accident was an erroneous assessment of the aircraft's climb capability required to clear the mountain.
- The aircraft was flying with a 3-knot tailwind, which created an unfavorable scenario for the steep ascent.
- The crew was carrying a heavy water load, which further limited the aircraft's performance.
- The crew attempted to minimize the impact energy by configuring the aircraft for a controlled strike without deploying the landing gear, as the terrain was unsuitable for a gear-down landing.
- The aircraft did not enter a stall; rather, it struck the terrain while maintaining sufficient airspeed, but lacked the vertical performance to overcome the slope.