Incident Summary
On April 30, 2008, at 16:15 UTC, a Tecnam P92 Echo, registration CS-UIJ, was flying from Azambuja (CVA) to Lagos (LPLG) on a leisure flight. The aircraft lost communications shortly after Setubal. Unable to contact air traffic control (ATC) and observing other signs of an electrical power failure, the pilot decided to land on the Quinta da Comporta agricultural runway to inspect the battery and electrical system. After landing, the pilot found the battery discharged but connections normal, and the voltage regulator appeared abnormally hot. The pilot then contacted the ARO (Air Traffic Services Reporting Office) by telephone to report the precautionary landing and cancel the flight plan, stating that the electrical fault prevented reliable radio communications and that he would proceed to Lagos without them. After landing at Lagos, the pilot informed ground services and arranged for a temporary repair of the voltage regulator. The aircraft, originally en route to join the APAU 2008 aerial tour, fulfilled subsequent legs without recurrence of the fault. The voltage regulator was later replaced at the home airfield. The pilot did not notify the GPIAA or INAC of the occurrence.
Aircraft and Crew Information
The aircraft was a lightweight, high-wing, tricycle-gear microlight (ULM) with a maximum take-off mass of 358 kg and two-seat capacity. The airframe was a Tecnam P-92 Echo (serial 268, built 1998) with a Rotax 912 engine of unspecified serial and time. The pilot, a 58-year-old Portuguese male, held flight license 394/UL/01 valid until 20 June 2008 with ULM 3-axis rating and a valid medical certificate dated 09 July 2007 (VDL limitation). His total flight experience was 607:30 hours, with 05:45 hours in the previous 90 days. The passenger was also a licensed microlight pilot. Maintenance records for the engine and cell were kept at the Azambuja airfield but were not provided to the investigation.
Analysis
According to ICAO Annex 2, Chapter 3, paragraph 3.6.5.2, a communications failure does not mandate an immediate landing; the pilot could have continued to the original destination. The pilot chose to land on the Quinta da Comporta runway, which was closed to all air traffic except for emergencies. The pilot did not declare an emergency, so the landing was considered a precautionary landing, not covered by the exception for emergencies. The analysis notes that landing on a closed runway with potential obstacles could have caused more harm than continuing the flight.
Conclusions
The pilot and aircraft were properly qualified and certified for the flight, and a flight plan had been filed. At the time of the communications failure, the aircraft was within the coverage of Lisbon FIS. The pilot opted for a precautionary landing on a runway closed to air traffic except for emergencies. After landing and identifying the fault, the pilot informed Lisbon ATC via ARO and continued to the destination. While the procedure was allowed under ICAO Annex 2 paragraph 3.6.5.2.1(a), it did not respect the prohibition on landing at a closed aerodrome. The pilot did not notify the investigation authority or the regulator as required.
Probable Cause
Not specified.