What happened
On July 20, 2005, at approximately 13:20 UTC, a PZL M-18-B (Dromally), registration SP-FOH, was engaged in aerial firefighting operations near Arganil, Portugal. The aircraft, operated by a Portuguese company, was performing water re-supply missions from the Coja aerodrome.
During the approach to land on runway 24, the pilot was unable to determine the current wind direction or intensity because the windsock was wrapped around its mast. Based on previous missions, the pilot selected runway 24; however, the wind had shifted to a northeast direction, resulting in a tailwind component. Due to this tailwind and an excessive approach speed, the aircraft touched down halfway down the runway, leaving only approximately 250 meters of available landing distance.
As the aircraft approached the end of the runway, which terminated in a ravine, the pilot applied heavy braking. Because the terrain was poorly compacted, the intense braking force caused the main landing gear to dig into the ground, leading the aircraft to capsize. The aircraft slid approximately one meter in an inverted position, resting on its propeller, cockpit, and vertical stabilizer. The pilot, the sole occupant, sustained only minor abrasions and escaped the wreckage uninjured.
The investigation
The GPIAAF investigation examined the aircraft's performance, the airfield conditions, and the meteorological data. The investigation established that the required landing distance for the aircraft under the prevailing conditions (40°C, 10-knot tailwind) was approximately 520 meters, whereas the total runway length was only 500 meters. The investigation also found that the aircraft's systems, including the braking system, were functioning correctly, and the aircraft's weight and balance were within safe limits.
Findings
- The primary cause was the pilot's decision to land on runway 24 with a tailwind, his decision to continue the landing maneuver after overshooting the touchdown zone, and the application of extreme braking.
- A contributing factor was the non-functional windsock, which prevented the pilot from identifying the wind shift.
- The lack of available meteorological information and radio communications at the temporary airfield hindered safe operations.
- The necessity of operating at the aircraft's performance limits due to the requirements of wildfire suppression contributed to the accident.
- Operational pressures, including fatigue and the high-stress nature of firefighting missions, were identified as contributing factors.