20030308008249A

(-23) Inspector statement: on 03-08-2003 I was notified by FAA com center of an incident/accident in Kinston north carolina. The accident involved a Fokker F-27 N712FE that had run off the side of rwy #5. The aircraft was operated by mountain air cargo (mtna) a 121 supplemental carrier. There were no injuries and the aircraft was sitting off the side of the runway. The airport was closed. Preliminary information on the accident was that the right hand main gear had collapsedon landing with the aircraft exiting the runway across taxiway A-3 coming to rest between the runway and taxiway. Reference: attachment #1. Mr. Phil powell of the NTSB was conferenced in on the phone call. I informed Mr. Powell that I would contact the necessary people to determine if the aircraft had received substantial damage and could be categorized as an accident. I contacted the Kinston tower and spoke to a controller named gean at 252-522-4844. Gean indicated that emergency personnel were on the scene. Gean informed me that the airport manager was in raleigh on the way back to Kinston. The controller indicated that the airport was closed, but within an hour would open back up with one runway open. I requested that gean inform the emergency personnel on scene not to move the aircraft until I arrived. Gean agreed to this. I next contacted mountain air cargo (mac) and spoke to the director of operations Mr. Sam street and mr .bill simpson president of mountain air cargo. Mr. Sam street informed me that the aircraft had left greensboro, NC en route to new bern, NC. The aircraft was making its approach into new bern when the pilots noted a right hand gear unsafe light. The flight crew discontinued the approach and contacted mac. Mac advised that the crew burn off excess fuel, follow the emergency procedures manual, and fly the aircraft to Kinston, NC for an emergency landing. Kinston, NC is mac's main maintenance base. Mac contacted the Kinston tower and informed the tower of the emergency landing. After talking to company personnel it was determined that the aircraft occurrence would be categorized as an accident due to the structural damage to the wing and nose of the aircraft. I informed the mountain air cargo personnel not to move the aircraft until I arrived on scene, and that I would need written statements from both crewmembers. Com center was contacted and informed that I was going to Kinston to perform an accident investigation. I arrived at the accident scene at 1630 local. Photos were taken of the touch down point on the runway, aircraft path, and the accident scene. I spoke to the flight crew and received their written statements. I released the aircraft to be moved to the hangar to determine what failed in the landing gear system to cause the accident. On 03-09-2003 the aircraft was put on aircraft jacks and a new drag strut installed. The gear was operated up and down with no air leaks noted. I next reviewed the landing gear control system in the Fokker tech data. Due to the nature of the failure just effecting the right gears system and not the left or nose, the system was segregated and analyzed. Air pressure to the right hand gear system was ruled out. Pressure checked good. The ram/actuator was removed and disassembled with no abnormalities noted. The ram/actuator internal snubber valve for gear free fall was disassembled and inspected with no abnormalities noted. The swivel lines to the ram/actuator were inspected with no abnormalities noted. The emergency gear extension shuttle valve was removed and inspected with no abnormalities noted. The emergency extension handle actuation was inspected with no abnormalities noted. The air supply to the system was inspected with no contamination noted. The lock strut was inspected with no abnormalities noted. The drag strut break point was initially thought to have been caused by the failure of the ram or emergency system, but was refocused on with all other portions of the system checking good. The drag strut break point was inspected, no beach marks were noted in the crack area, but the drag strut failure point and metal tear and shear points indicated that the drag strut failed from being pulled up by the ram/actuator. The main gear front door that is attached to the top of the drag strut was noted as being bent forward not backward in the direction of impact. The failed drag strut was reinstalled and the bent main gear front door bend aligned with the failed drag strut. With the drag strut and the main gear front door aligned it showed that the drag strut had initially failed being pulled up into the gear wheel well, damaging the lock strut micro switch which in turn caused the gear unsafe light. Reference attachment #2 and #3. With the aforementioned established a tech data evaluation was performed revealing a dowty rotol service bulletin 32-42S dated 8-28-1981 and a caa, AD/F27/104 on the subject. Mac personnel were told to quarantine the broken drag strut until the NTSB was contacted to see if they wanted the drag strut to go to their lab for testing. The NTSB was contacted on 03-10-2003 and updated. On 03-11-2003 the NTSB requested that the drag strut be sent to the NTSB for analysis. Mac was contacted and given the NTSB address of where to send the drag strut. The following items were faxed to the NTSB for review. A. isis airmen report b. pilot written statements c. crewmember data sheets d. caa AD/F27/104 e. dowty rotol service bulletin 34-42S. Pending the NTSB lab report a safety recommendation will be drafted and sent to Washington suggesting a repetitive ndt inspection on the drag strut, in lieu of the one-time inspection noted in the dowty rotol service bulletin.