History of the Flight
The aircraft departed Antigua for the scheduled return flight to Montserrat. The destination was experiencing heavy rain showers, which the pilot monitored. The aircraft held north of the island, descending to remain in visual contact with the sea in turbulent conditions. After the showers moved away, the pilot obtained clearance for a left-hand downwind for Runway 10. The wind was reported as 140° at 6 kt, later updated to 210° at 6 kt. The runway was wet, and the pilot continued the approach with full flap and an approach speed of 65 KIAS. Witnesses reported the touchdown was faster than normal. The pilot applied brakes, which had little effect. As the aircraft passed the taxiway intersection, the pilot applied harder braking. Nearing the runway end, the pilot applied full right aileron and rudder to turn onto grass, but the aircraft skidded through 180° to the right and went backwards over the edge, stopping when the tail struck the perimeter fence. All occupants evacuated without injury.
Accident Site
Skid marks on the runway indicated the aircraft skidded approximately 150 m before veering onto grass about 19 m from the runway end. The aircraft continued across grass, leaving tyre marks. The right main wheels struck a runway threshold light. The aircraft rotated 180° immediately before dropping backward down a sloping ravine. Dense reeds and bushes slowed its rearward motion, and it stopped when the left tailplane and wingtip struck the barbed wire and chain-link fence about 8 m below runway level. The aircraft came to rest at an approximate 30° angle.
Recorded Information
CCTV from the ATC tower recorded the final approach and touchdown. The touchdown groundspeed was estimated at 79 kt.
Aircraft Examination
Damage was mostly to the rear: the left tailplane main spar broke at the root and bent upward; the elevator was similarly damaged. The rear anti-collision light was displaced. The left wingtip fairing and outer aileron were dented. The landing gear and wheel brakes were undamaged. Tyres did not deflate, but the nose and right inner mainwheel had grass trapped between bead and rim. Blistering was present on three mainwheel tyres; the right outer tyre showed blistering on edges and centre tread. The right main landing gear strut was slightly displaced outward. The nav-comm unit mounting rack appeared undamaged. A passenger seat covering panel detached during hurried evacuation.
Landing Performance
At the estimated landing weight of 6,220 lbs, the Landing Distance Required (LDR) for a dry, level runway is 448 m. For a wet runway, 15% is added, resulting in 515 m. This assumes an approach speed of 65 KIAS reduced to 58 KIAS at threshold. The operator expects pilots to touch down as close as safely possible to the threshold.
Probable Cause
The aircraft's touchdown groundspeed of 79 kt was higher than appropriate, either due to an approach airspeed greater than normal or a significant change in windspeed and direction. This, combined with a wet runway and skidding, resulted in the aircraft requiring more distance to stop than was available.