19991019029999A

(-23) On initial approach to southern pines airport (SOP) when the landing gear was extended left main gear unsafe light indicated left lndg gear unsafe. Pilot orbited SOP airport twice, cycled gear and proceeded with emergency gear extension to no avail. Aircraft diverted to Fayetteville (fay). Upon arrival at fay, aircraft made several flyby's at 200' to assess situation, dove a/c & yawed a/c, in an effort to free gear down to no avail. After burning fuel down to 30 minuts, a/c made long approach to final at 110 KTS. Pilot made right gear landing in an attempt to bounce left gear down to no avail. A go around was accomplished and aircraft burned off fuel to 20 min. Passenger was briefed on emergency procedures. A/c again did long straight in approach at 110 KTS. Upon landing, left main gear appears to have collapsed. Left wing skidded along r/w. left outboard flap and flap faring skidded on runway & left main gear inboard door ground along r/w. a/c came to stop on r/w centerline 2000 ft from end. A/c evacuated w/o injury. Minimal damage to a/c & emergency procedures followed. (.19) on October 19, 1999, about 0101 eastern daylight time, a british aerospace ha 125-70 0A, N34GG, registered to and operated by N34GG, lic, was landed with the left main landing gear retracted at the Fayetteville Regional/Grannis field airport, Fayetteville, north carolina. Visual meteorological conditions prevailed at the time and an IFR flight plan was filed for the 14 CFR part 91 business flight. The airplane sustained minor damage and the commercial-rated pilot and copilot, and one passenger were not injured. The flight originated about 1700 pacific daylight time from the mccarran international airport, las vegas, Nevada. The pilot stated that when the flight entered the traffic pattern at the destination airport and the landing gear was extended, there was no down and locked indication for the left main landing gear via the normal or alternate indication systems. The pilot briefed the passenger what was occurring and what would occur, advised air traffic control of the situation, climbed and orbited over the airport and cycled the landing gear three or four times. There was no down and locked indication from the left main landing gear. At the pilot's request, the flight was vectored to the nearest airport with facilities, which was the Fayetteville airpor t. the pilot performed six fly-bys of the air traffic control tower located there for confirmation of the position of the left main landing gear. The pilot then initiated a climb to 8,000 feet where he initiated a series of "g" loading maneuvers and parabolic arcs with simultaneous yaw and gear extension with no success in extending the left main landing gear. The flight returned for landing at the Fayetteville airport and after touchdown first on the right main landing gear, the left wing began to settle lower than usual. The pilot initiated a go-around, again briefed the passenger, and returned for landing. After touchdown, the airplane remained on the runway with the application of right brake and rudder input. Preliminary examination of the left maiin landing gear revealed that the main gear jack cylinder head part number air 111506, exhibited broken lugs at the jack cylinder head location. (.4) upon entering the traffic pattern at the destination airport, the landing gear was extended using the normal and alternate methods, the left main landing gear did not extend. The flight departed the traffic pattern, orb orbited the airport an attempts to extend the left main landing gear were unsuccessful. The flight diverted for an airport with fire rescue, performed a fly-by, then climbed to altitude where 'g-loading maneuvers were performed to extend the left main landing gear. The gear could not be extended. The airplane was landed with the left main landing gear retracted. Examination of the airplane revealed that the lugs on the cylinder head of the left main landing gear jack were fractured. Metallurgical examination of the fractured lugs of the cylinder head revealed overstress failure; no evidence of progressive (fatigue or stress corrosion) cracking was observed. The cylinder head is a 5,000 cycle life limited component and the failed cylinder head which was installed when the airplane was manufactured, had accumulated 4,751 cycles at the time of failure including the accident landing. The jack attachment and surrounding area required to be inspected every 600 hours, was inspected last 348 hours and 299 cycles earlier; no discrepancies were noted.