What happened
On 18 December 2011, an M-28, registration 08-0319, departed Kandahar Air Base, Afghanistan, as part of a multi-leg mission involving passenger transport between Qalat and the Walan Rabat short takeoff and landing zone. The aircraft and crew were part of the 318th Special Operations Squadron, deployed to Kandahar.
After picking up four passengers in Qalat, the aircraft proceeded to the Walan Rabat landing zone. At the time of the approach, surface winds were reported at 190 degrees at 14 knots, gusting to 17 knots. Because of the terrain, including a nearby mountain and a three percent upslope on runway 34, the pilot chose to land with a tailwind component. The landing zone itself was a narrow, 1,756-foot long dirt strip with limited boundaries.
During the approach, the pilot maintained a shallow descent angle of approximately 2.5 to 3 degrees. Upon landing at 1032 Zulu, the aircraft experienced a heavy touchdown and veered toward the right side of the prepared surface. As the aircraft left the strip, the nose gear struck uneven ground and collapsed, resulting in the M-28 flipping tail-over-nose. All crew and passengers successfully exited the aircraft through a side window. There were no serious injuries reported among the occupants, and no civilian casualties occurred. The aircraft was destroyed in the accident.
Findings
Investigation into the accident revealed that the pilot incorrectly calculated the tailwind component using a wind component chart. This error led the pilot to believe the wind conditions were within the safe operational limits for the M-28 during landing.