What happened
On 4 September 2005, a PZL M18A Dromader, registration EC-GAB, departed from the El Rebollar Aerodrome in Requena, Valencia, to participate in a firefighting mission. The aircraft was operating under visual flight rules (VFR) and was heavily loaded with water for the purpose of combating a forest fire near the town of Montroy.
Following takeoff, the aircraft was intended to perform a slow right turn before executing a 180-degree left turn to avoid local obstacles. During this maneuver, the aircraft entered a steep left bank. The aircraft subsequently crashed into the ground near the airfield, resulting in the death of the pilot and the total destruction of the aircraft.
The investigation
The CIAIAC investigation examined the aircraft's performance capabilities, the pilot's qualifications, and the configuration of the stall warning system. Investigators analyzed the aircraft's weight, noting it was operating at 4,950 kg, which exceeded the basic flight manual's maximum takeoff weight of 4,200 kg but was permitted under a specific Supplementary Type Certificate (STC).
Technical inspections of the wreckage and components revealed that the engine was at high power at the moment of impact and no mechanical failures were found. The investigation also focused on the stall warning system, which was found to be manually disconnected in the cockpit. Furthermore, the investigators reviewed the discrepancy between the Spanish airworthiness certificates and newer EASA standards regarding operational limits for high-weight firefighting missions.
Findings
- The aircraft was operating at a high weight of 4,950 kg.
- The pilot executed a bank angle of approximately 30 degrees, which significantly exceeded the manufacturer's recommended limit of 15 degrees.
- The stall warning system had been manually disconnected by the crew.
- The pilot possessed limited experience on this specific aircraft type.
- The aircraft was in a level attitude with a high descent rate and low airspeed at the moment of impact.