N5432M

On March 14, 1995, at 1450 mountain standard time, a Cessna 340, N5432M, sustained substantial damage when the right main gear collapsed during landing near Santa Fe, New Mexico. The private pilot and the sole passenger were not injured. Visual meteorological conditions prevailed for the local personal flight being operated under Title 14 CFR Part 91.

The flight was cleared by the tower controller to land on runway 02 and during the landing roll, the right main gear collapsed. The right wing struck the runway and the airplane came to rest with damage to the right aileron, flap, propeller, landing light, and wing tip fuel tank.

The landing gear was checked and lubricated at an annual inspection on March 26, 1994, at Robertson Aircraft, Inc., at Albuquerque, New Mexico. Robertson wrote an airplane discrepancy log entry for April 29, 1994, stating "check landing gear" and listing under the corrective action block that "gear needs all new bushings and tension set." The log further stated that the "pilot said not to do anything." On August 10, 1994, a pre-purchase inspection report (copy enclosed) for the current owner listed numerous landing gear system discrepancies including right main gear side brace "play at the upper attachment point and at the center pivot point." The inspection report also stated "gear tensions low, gear system needs rigging."

The airplane was purchased by the current owner on October 11, 1994. In November 1994, maintenance was accomplished on the landing gear transmission, manual gear extension system, the left main gear assembly (including replacement of bushings in drag link); however, maintenance records did not indicate work on the right main gear assembly. In December 1994, maintenance included gear box repair, installation of new bushings in the left gear and adjusting the up and down locks and overcenter pressures.

After 4.6 hours of flight time since the last recorded landing gear maintenance, the right main gear collapsed, on February 2, 1995. The enclosed inspection sheet, work order, and parts listing did not reveal replacement of main gear bushings. The maintenance logbook states "performed gear rig and operational test." On the enclosed statement, dated September 19, 1995, Beegles Aircraft Service, Inc., stated that after the first gear collapse, a "replacement of parts and inspection of the other parts was completed and gear rigging procedure completed." Beegles Aircraft further stated that the "gear system rigged out according to the manual." On March 1, 1995, Beegles Aircraft Service of Greeley, Colorado, stated in the maintenance log that the "aircraft was repaired and inspected" and "is approved for return to service."

On March 14, 1995, 7.7 hours of flight time after the first gear collapse, the right main gear collapsed for a second time. In April 1995, the airplane was examined at Beegles Aircraft Service, Inc., by a NTSB investigator and the manufacturer's technical representative. The technical representative found "the whole landing gear system was extremely worn" and "every place there was a bearing, bushing, or bolt was excessively worn." According to the technical representative, "the extreme wear of the complete gear actuating system caused the gear rigging parameters to change with each actuation and at the time of collapse, had changed enough to prevent the downlock from locking properly." On the enclosed statement, Beegles Aircraft Service, Inc., reported that after the second gear collapse they became aware of the maintenance on gear door hinges and the transmission.

On May 16, 1995, the manufacturer's engineer reviewed the history of the airplane and stated that it was his "suspicion that the rigging of the aircraft is changing and that the right gear is loosing its over center adjustment as a result of the existing crack in the gear box area as well as the worn out bushings." On the enclosed statement, Beegles Aircraft Service, Inc., reported that "the wing rib in the main gear wheel well of this airplane have cracks" as outlined in the Cessna Service Letter ME76-2. Airplane maintenance records did not indicated that the service letter had not been accomplished by previous owners or maintenance personnel.

The right upper struts and bellcranks from the two occurrences of the right main gear collapse were examined by the NTSB Metallurgists. Each strut and bellcrank contained "similar separations" and disclosed "no evidence of preexisting fractures." All fractures were "typical of overstress."

The airplane was released to the owner.