20160510023909A

On may 10, 2016 at approximately 17:15 local time a twin turboprop king air landed with the right hand main landing gear collapsing upon touchdown. The aircraft involved was a Beech B100 s/n BE-22 registration N86TR and had 4 persons aboard. No injuries were reported. Initial inspection indicates the r/h main landing gear collapsed upon landing. The aircraft was found 125 feet west of the runway edge and 2518 feet from the runway one-eight approach end. Markings on the runway indicate the aircraft touched down on runway one-eight 400 feet from the approach end. The r/h prop began striking the runway at 544 feet and continued striking till the aircraft came to rest. The aircraft was found resting on its r/h wing and two remaining down and locked landing gears.

The pilot stated a normal approach with normal approach configuration was made and upon touchdown the right hand wing kept settling which eventually caused the aircraft to veer to the right and depart the runway. The pilot in command and right seat occupant (pilot rated) both stated that three green gear down and locked lights were illuminated prior to landing.

The r/h prop blades were found bent backwards and displayed evidence of prop strike. The r/h wing contained damage to the wing tip, wing leading edge, wrinkling of the top skin and unknown damage to the underside of the wing. The r/h main landing gear was not accessible or viewable at this time. The flaps were in the up position along with the flap control handle ? No initial damage was noted to any flight control surfaces at this time.

Post aircraft recovery revealed the bottom right wing skin to the integral fuel tank was torn resulting in an approximate 5 by 3 inch hole. The right hand main gear actuator assembly has numerous bent parts and was broken out of its mounting structure. The inboard top actuator mounting structure was torn away from the airframe. The right hand nacelle fuel tank bulkhead was ruptured with the top of the gear actuator resting inside the tank area. The top wing skin wrinkling was not as evident post recovery but still shows signs of damage. Puncture damage to the fuselage pressure vessel was noted in 5 places below the copilot side window and a two inch crack or tear was found on the belly skin approximately centered between the main gear legs. Other unknown hidden damage may exist.

The NTSB inspector mitchell gallo provided accident number CEN16LA187.

Contact was made with Textron aviation paul yoos (air safety investigator) to help determine any maintenance or mechanical issues.

Maintenance records show landing gear work was performed 10 flight hours prior to accident by certified repair station (crs) # Z4AR. No deficiencies were noted from review of the work order package form crs #Z4AR. The airworthiness directives were reviewed and appear to be in compliance at this time.

The PIC was re-interviewed. His statements were consistent with others that the aircraft was landed in a normal configuration and had three green gear down indications prior to touchdown. No other anomalies were noted during the landing sequence other than the rmlg collapsing upon touchdown.

The belly inspection panel was removed to verify condition of the gear drive motor assembly which appeared to be intact with no issues. The access panel below the r/h battery was removed to verify the condition of the driveshaft which was found disconnected at the splined section. The driveshaft appears to have been disconnected when the right hand gear actuator broke away from its mounting structure pulling the driveshaft off its splined connection.

The NTSB inspector mitchell gallo was contacted and concurred that the right hand landing gear down lock and or actuator components failed for reasons unknown.