What happened
On the afternoon of January 25, 2009, a private PIPER PA-28-161, registration EC-DSD, was conducting a local VFR flight around the island of Tenerife. The flight, which included the pilot and two passengers, was intended to follow the coastline in a clockwise direction, departing from Tenerife North Airport.
During the flight, air traffic controllers notified the pilot that weather conditions at the airport were beginning to degrade. As the aircraft approached the Teno area, the pilot requested Special VFR (VFR Especial) status to proceed from point W to point S, aiming to fly over the island to reach the airport quickly. The last radio contact with the aircraft occurred at 13:34:40 h, after which radar contact was lost.
The aircraft was later located the same day at the base of the northern slope of Montaña de la Crucita. The PIPER PA-28-161 had impacted the terrain nose-first in a steep area, resulting in the destruction of the aircraft. Despite the violence of the impact, the crew and passengers survived with two serious injuries.
The investigation
Investigators reconstructed the aircraft's radar track, which revealed that the pilot performed a tight turn approximately 5 km before reaching point W. This maneuver resulted in a flight path that was further south than intended, placing the aircraft on a course toward the high peaks of the island's central mountain range.
Radar data showed that between the final radar detections, the aircraft was climbing at a rate of approximately 574 ft/min. While this rate exceeded the maximum climb rates listed in the flight manual for maximum takeoff weight at similar altitudes, the investigation noted that the aircraft's actual weight was likely lower, allowing for a better climb. However, the investigation established that the aircraft was flying at an altitude of approximately 5,700 ft, which was insufficient to clear the peaks of the mountain range, such as Montaña de la Crucita, which reaches 6,761 ft.
Findings
- The primary cause of the accident was the loss of visual references by the pilot due to rapidly deteriorating meteorological conditions, including the onset of clouds and fog.
- The pilot's flight path took the aircraft directly toward high terrain while flying in IMC (Instrument Meteorological Conditions) conditions under a Special VFR authorization.
- An inadequate assessment of the weather forecast was a contributing factor, as the pilot did not sufficiently account for the predicted rapid degradation of visibility and cloud cover.
- The pilot failed to establish an alternative flight plan or contingency for encountering difficult weather conditions while traversing the island's interior.