Accident Overview
The airplane experienced a right main landing gear collapse while landing at the destination airport. The right lower wing skin sustained substantial damage when it contacted the runway. The crew brought the airplane to a stop on the runway and initiated an emergency evacuation through three of the four available doors.
Escape Slide Malfunction
The escape slide at the left forward door failed to deploy or inflate. The failure was attributed to depletion of the gas charge in the slide's reservoir. The reservoir had been leaking through the valve assembly, and the leak was not detected during multiple inspections performed after the slide assembly was installed on the airplane.
Landing Gear Failure
The landing gear cylinder fractured under normal landing loads. Metallurgical examination revealed a fatigue crack on the forward side of the cylinder, located in an area subject to inspections mandated by an Airworthiness Directive (AD). The most recent AD inspection had been conducted 218 landings prior to the accident; at that time, the fatigue crack was large enough to be detectable. A previous AD inspection, performed 497 landings before the accident, also failed to identify the crack, which would have been marginally detectable at that point.
Probable Cause
The official finding stated the probable cause as: "The failure of the right main landing gear under normal loads due to fatigue cracking in an area subject to an FAA Airworthiness Directive that was not adequately inspected."