What happened
On November 14, 2011, a Cessna 150 was performing an instrument flight from Santa Rosa to Guayaquil, Ecuador. The aircraft was operated by a pilot with a commercial license and carried one passenger. After departing Santa Rosa airport, the pilot was cleared to climb to 4,000 feet and follow airway G675 toward the Guayaquil VOR.
At approximately 20:26 UTC, the pilot reported passing the Machala VOR. This was the final communication received from the aircraft. The plane was later discovered crashed in the Virón Alto sector at an altitude of 4,062 feet. The impact with the mountain slope caused the nose gear to detach and the wing structure to fail, resulting in the total destruction of the aircraft. Both occupants sustained fatal injuries due to the forces of the impact.
The investigation
The investigation examined the flight records, maintenance logs, and meteorological reports for the area. Investigators confirmed that all navigational aids at Santa Rosa were functioning normally and that the aircraft's airworthiness certificate was valid. While local weather reports indicated visibility was sufficient for visual flight rules (VFR), the investigators noted that the specific crash site was covered in low clouds and mist, a common occurrence in that mountainous region.
Technical analysis of the navigation equipment revealed that the VOR was tuned to the correct frequency for Machala. However, investigators focused on the pilot's interaction with the instrument settings during the flight. The investigation also reviewed the pilot's recent experience, noting he had completed approximately 23.7 hours of instrument flight training in the months leading up to the accident.
Findings
- Incorrect VOR radial selection: The pilot mistakenly entered the value 142 into the lower portion of the VOR instrument instead of the upper portion. This caused the instrument to automatically select the reciprocal radial of 322 degrees.
- Navigational error: Because of this incorrect setting, the VOR needle deflected to the right, prompting the pilot to turn right. This maneuver directed the aircraft toward the mountain range rather than along the authorized departure path.
- Lack of cross-checking: The pilot failed to verify the TO/FROM flag on the VOR or monitor the DME distance, which would have indicated that the aircraft was moving away from the station rather than toward it.
- Spatial disorientation: The error led to a state of disorientation where the pilot believed he was following the correct procedure and maintaining a safe altitude above obstacles.
- Inadequate procedural verification: There was a failure to properly verify the assigned instrument departure procedure prior to the flight.