What happened
On October 17, 2019, a PenAir Saab 2000, registration N686PA, overran the runway during landing at Tom Madsen Airport in Unalaska, Alaska. The flight, operating from Anchorage, was performing a scheduled passenger service when the aircraft failed to stop within the runway limits. After exiting the paved surface, the plane breached the airport's perimeter fence, crossed a public road, and eventually came to a halt among rocks on the shoreline.
The incident resulted in one fatality and several other passengers sustaining serious or minor injuries. The aircraft sustained substantial damage, including significant structural impact to the fuselage and propeller assemblies.
The investigation
Investigators examined the wreckage, runway markings, and maintenance records, while also reviewing cockpit voice and flight data recorder information. The investigation focused on the aircraft's performance during the landing roll and the condition of the landing gear.
Data from the flight recorders showed that the aircraft touched down at a ground speed of approximately 142 knots. Following touchdown, the crew utilized reverse thrust and wheel braking. However, approximately 25 seconds after the main gear made contact with the runway, the aircraft experienced a change in pitch and roll, indicating it had departed the runway surface.
Physical examination of the landing gear revealed that the left outboard tire was deflated and had been worn through. Additionally, the investigation noted significant damage to the propeller assemblies; on the left engine, several propeller blades were missing or fractured, and pieces of the blades were found both outside and inside the aircraft cabin. On the right engine, the tips of all six propeller blades had broken away.
Findings
- The aircraft touched down approximately 1,000 feet down the runway during its second approach.
- The left outboard main landing gear tire was deflated, with an area of the tire worn entirely through.
- During the landing roll, the aircraft experienced significant forces consistent with departing the runway surface.
- The aircraft's path involved striking a perimeter fence, a signal post, and a road sign before coming to rest.