What happened
On April 30, 2008, a Tecnam P92 Echo, registration CS-UIJ, was conducting a leisure flight from Azambuja to Lagos. Shortly after passing Setúbal, the pilot experienced a loss of radio communications. Concurrently, the pilot observed signs of an onboard electrical failure.
To investigate the electrical status, the pilot decided to perform a precautionary landing at the Quinta da Comporta agricultural airstrip. Upon landing, an inspection revealed that the aircraft battery was discharged, and the voltage regulator was operating at an abnormally high temperature. After addressing the battery issue, the pilot contacted the Air Traffic Services Reporting Office (ARO) via telephone to report the landing and to cancel the original flight plan, noting that the electrical malfunction prevented further radio communications. The pilot then continued the flight to Lagos, where the electrical issue was temporarily resolved, allowing the aircraft to complete its scheduled flight group activities.
The investigation
The GPIAAF investigation examined the pilot's decision-making process and the status of the landing site. The investigation established that the Quinta da Comporta airstrip was a private, uncertified agricultural field that was officially closed to all air traffic due to its location within a national ecological reserve. The investigation also noted that the pilot failed to notify the GPIAAF or the National Civil Aviation Authority (INAC) of the occurrence, despite the mandatory reporting requirements for such incidents.
Findings
- The pilot's decision to land at the closed airstrip was deemed inappropriate, as the site was not a certified aerodrome and was specifically closed to traffic.
- While ICAO Annex 2 regulations allow pilots to continue to their destination following a loss of communications, the pilot's choice of landing site presented potential risks, including unverified obstacles or surface irregularities on the uncertified strip.
- The primary cause of the communication loss was an electrical malfunction involving a discharged battery and an overheating voltage regulator.
- The pilot did not declare a formal emergency, characterizing the event as a precautionary landing.
- There was a failure to comply with mandatory reporting procedures regarding the notification of the accident investigation office.