What happened
On September 3, 2012, at approximately 11:05 UTC, a Kamov KA-32A11BC helicopter, registration CS-HMO, was engaged in firefighting operations near Ourém, Portugal. The aircraft, operated by Empresa de Meios Aéreos – EMA, S.A., was equipped with a "Bambi Bucket" for water drops. After performing several successful water drops from a nearby lagoon, the crew attempted to climb and transition after a re-supply maneuver.
During this climb, the aircraft experienced a sudden failure of engine number one. Although the crew increased the collective pitch and the remaining engine accelerated to "Extraordinary Power Mode," the helicopter could not maintain altitude. The aircraft struck the ground approximately 10 meters from its initial position. The external load, the Bambi Bucket, was not released prior to impact. Following the crash, the second engine stopped on its own. The commander escaped the wreckage uninjured, while the co-pilot sustained minor injuries, including a broken toe.
The investigation
The GPIAAF investigation examined the wreckage, flight data from the 36H-2M combined flight recorder, and engine components. Investigators noted that while the cockpit environment appeared normal on the audio recordings, the flight parameters showed a critical loss of power. A borescope inspection of engine number one revealed extensive destruction of the high-pressure turbine stages and the first stage of the free turbine due to thermal and mechanical fractures. Engine number two appeared functional, though investigators found mud and debris in the air intakes, likely ingested from the water bucket during the impact.
Additionally, the investigation identified discrepancies in engine maintenance records. Specifically, there were inconsistencies regarding the recording of engine operating hours in certain modes and the use of an outdated maintenance manual version for certain procedures.
Findings
- The primary cause of the accident was the failure of engine number one during the climb following a water re-supply.
- The aircraft was unable to maintain flight despite the second engine reaching emergency power levels.
- The crew did not release the Bambi Bucket before the impact.
- The investigation identified that engine number one suffered significant internal damage characterized by fractured turbine blades and components.
- Maintenance records showed that some operational parameters and adjustments were not properly documented in the engine logbooks.