What happened
On January 27, 2013, an Aero Boero AB-115, registration PP-GHE, was conducting a flight instruction mission from Recife International Airport (SBRF) to the Encanta Moça Aerodrome (SNEM). After completing a missed approach training maneuver at the destination, the crew began the return flight to Recife. While operating in the traffic pattern at SNEM, the engine suffered a loss of power. The pilot attempted an emergency landing in a mangrove area located approximately one thousand meters from the threshold of runway 16. During the landing, the aircraft nose-over, resulting in substantial damage to the airframe. Both occupants of the aircraft remained uninjured.
The investigation
CENIPA investigators examined the engine (Lycoming O-235-C2A) and discovered significant deterioration of the spark plugs, characterized by oxidation and electrode wear. This degradation was determined to be an old condition unrelated to the engine's immersion in water. The investigation also revealed that the engine had undergone an overhaul and was returned to service only 14 days prior to the accident.
While the aircraft's logbook contained no recorded discrepancies for the flight in question, evidence emerged that the day before the accident, the aircraft had exhibited performance issues, specifically failing to reach the cruise speed specified in the Operating Manual. Although the maintenance workshop had recommended that the aircraft be withdrawn from service, the flight was still conducted. Furthermore, records showed that the flight club had recently inquired with a parts distributor regarding the purchase of new spark plugs, indicating an existing concern regarding engine components despite the recent overhaul.
Findings
- Inadequate management oversight regarding the decision to continue flight operations despite known performance issues.
- Significant deterioration and oxidation of the engine spark plugs.
- Failure to follow maintenance recommendations to ground the aircraft following observed power loss symptoms.
- Deficiencies in maintenance quality control and management planning.