Incident Overview
On 25 March 2009, a Dornier DO-228-202, registration CS-TGO, operated by SATA Air Açores, was conducting a scheduled passenger flight (call sign SP850) from Horta Airport to Corvo Airport. The aircraft had 2 crew and 9 passengers on board.
Sequence of Events
The flight to Corvo was uneventful, with good weather and calm winds at Corvo. At 12:05 UTC, the crew reported on final approach to runway 12 at Corvo. After selecting the landing gear down, the Caution Light NWS Bypass and Master Caution Light illuminated on the instrument panel. The crew requested clearance to orbit between the islands of Flores and Corvo to assess the problem. At 12:12, the pilot requested to proceed to Lajes Airport on Terceira Island. At 12:17, the crew declared an emergency due to a hydraulic failure. The aircraft landed at Lajes Airport at 13:18 without further incident.
Maintenance and Return to Service
On the ground at Lajes, maintenance personnel replaced the landing gear down line. After performing tests in accordance with the Aircraft Maintenance Manual (AMM), the aircraft was cleared for service and subsequently completed three additional flights that day with no further issues.
Analysis and Conclusions
The incident was caused by a hydraulic leak in the landing gear down line when the crew extended the gear for landing. The crew elected to divert to Lajes Airport, which offered better technical and operational support for the situation. The main cause of the incident was determined to be a hydraulic leak in the gear down line.