History of Flight
On 15 September 2014, at approximately 0834Z, Air Tractor AT-802A ZS-TBW (call sign Bomber 9) and another Air Tractor (Bomber 95) were dispatched from Piet Retief Airfield (FAPF) for a fire-fighting mission at Speenkoppies Mondi Vrede Farm in Mpumalanga Province. At the same time, two additional Air Tractor aircraft (Bomber 10 and Bomber 11) departed from Piet Retief Municipal airstrip for the same mission. Earlier that day, Bomber 9 had experienced a failure of its gatebox doors to open, preventing the release of fire retardant. The pilot reported that the Gen I Fire Retardant Dispensing System (FRDS) issue was resolved, and the load was successfully dropped. All aircraft then returned to base and were stood down by the Incident Commander.
At approximately 1036Z, another forest fire was reported at Mondi Vrede Farm. The four Air Tractors and a Cessna spotter aircraft were dispatched. During the 13th approach, Bomber 9 (in position 2 behind Bomber 95) again could not release its load due to the gatebox doors not opening. The aircraft descended to about 50 feet above ground level (AGL) in a nose-up attitude and impacted pine trees, severing the right-hand wing. The aircraft then rolled right through 180 degrees into an inverted attitude and struck the ground nose-down at an angle of approximately 70 degrees. It skidded and ground-looped before coming to rest facing the approach direction. The pilot sustained fatal injuries, and the aircraft was destroyed.
Injuries to Persons
The pilot, the sole occupant, suffered fatal injuries. No other persons were injured.
Damage to Aircraft
The aircraft was destroyed in the impact sequence.
Other Damage
Pine trees at the accident site were damaged.
Personnel Information
The pilot was a 65-year-old male South African, holding a Commercial Pilot Licence valid with type endorsement for the Air Tractor AT-802A. He had a total of 19,796.1 flying hours, with 68 hours on type. He had completed an AT-802A class rating course in Spain in June 2013 and FRDS training in December 2013. The operator had assessed him as competent for fire-fighting duties.
Probable Cause
The aircraft right wing collided with trees during a right bank in an attempt to avoid collision with the trees.
Contributory factors included the likelihood that the FRDS was operated before reaching the required 3000 psi operating pressure, the aircraft operating at low speed as required by the Airplane Flight Manual, and the hilly terrain (though the aircraft avoided the hills themselves, it struck trees planted on the terrain).