FTW97LA370

After takeoff, about 300 to 400 feet above ground level, the pilot raised the gear lever and the green landing gear down annunciator light remained illuminated. He then cycled the gear lever to the down position and returned to land to check the gear. Upon touchdown, the right main landing gear retracted. The aircraft skidded down the runway and turned 180 degrees to the left, remaining on the runway. The right main hydraulic landing gear actuator (P/N 1281000-1, S/N 1039) was sent to the NTSB's Materials Laboratory for examination. A second hydraulic actuator (P/N 1281000-1, S/N 1790) that received damage due to overstressing caused by an off airport landing was sent to the laboratory for comparison. Both hydraulic actuator housing assemblies exhibited similar longitudinal fractures in their respective housings. Both of the housings were bulged outward near the midpoint of the longitudinal fracture. Examination of the fractures with the aid of a scanning electron microscope revealed that the fracture characteristics were typical of an overstress separation. Neither examples exhibited evidence of progressive cracking.

On September 29, 1997, at 1350 mountain daylight time, a Cessna 210L airplane, N59217, owned by a private individual and operated by New Mexico Flying Service, Albuquerque, New Mexico, was substantially damaged following the collapse of the right main gear during landing roll at the Albuquerque International Airport, Albuquerque, New Mexico. The commercial pilot, sole occupant of the airplane, was not injured. The Title 14 CFR Part 135 non-scheduled cargo flight, for which a VFR flight plan was filed, originated from Albuquerque International Airport at 1340.

The pilot reported that he planned the flight from Albuquerque (ABQ) to Portales (Q34), New Mexico. He performed a run-up with no reported discrepancies and proceeded to take-off from runway 08. Approximately 300 to 400 feet above ground level the pilot raised the gear lever and the green "landing gear down" annunciator light remained illuminated. The pilot stated that he did not hear the gear retract. He then cycled the gear lever to the "down" position and advised the control tower of his situation and requested to return to the airport. The tower cleared the pilot to land on runway 30. Upon touchdown, the right main landing gear collapsed. Subsequently, the aircraft skidded down the runway and turned 180 degrees to the left, remaining on the runway. The aircraft came to rest upright, resting on the right wing tip and right horizontal stabilizer.

An FAA inspector reported that the right horizontal stabilizer was structurally damaged. The right main landing gear actuator housing was found split and was retained for further examination. Other than the actuator assembly, no additional pre-existing anomalies were found within the landing gear system.

The right main hydraulic landing gear actuator (p/n 1281000-1, s/n 1039) was sent to the National Transportation Safety Board materials laboratory, in Washington D.C., for examination. A second hydraulic actuator (p/n 1281000-1, s/n 1790), that received damage due to overstressing caused by an off airport landing, was sent to the laboratory for comparison. Both hydraulic actuator housing assemblies exhibited similar longitudinal fractures in their respective housings. Both of the housings were bulged outward near the mid-point of the longitudinal fracture. Examination of the fractures with the aid of a scanning electron microscope revealed that the fracture characteristics were typical of an overstress separation. Neither examples exhibited evidence of progressive cracking.

A detailed Materials Factual Report is attached to this document.