Accident Overview
On July 8, 2010, at 2006 central daylight time, a Cessna 210L (registration N2157S) experienced a right main landing gear collapse while landing at Ellington Field Airport (EFD) in Houston, Texas. The aircraft, operated by Air Transit Solutions LLC under 14 Code of Federal Regulations Part 135 as an on-demand cargo flight, was substantially damaged. The sole occupant, the pilot, was not injured. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed.
Flight Sequence
The flight departed Castroville Municipal Airport (CVB) at 1700 en route to EFD. During approach, the pilot moved the landing gear handle to the down position. The hydraulic gear motor activated, and the landing gear began to extend, but the pilot did not receive a green gear-down indicator light and visually confirmed that the gear did not appear fully extended. The pilot executed a go-around and departed the traffic pattern to troubleshoot the gear extension problem. He consulted with his company via radio and completed several checklist items, including a "G maneuver." All attempts to extend the gear failed, leading the pilot to prepare for a gear-up landing.
Landing and Damage
During touchdown, the left main and nose landing gear remained down and locked, but the right main landing gear collapsed. The airplane veered off the right side of the runway and came to rest in a grassy area. The right wing contacted the ground, resulting in substantial damage to the right wing and right horizontal stabilizer.
Hydraulic System Examination
In the Cessna 210L, landing gear extension and retraction is achieved via hydraulic actuators powered by an electrically driven hydraulic power pack or an emergency hand pump. Sufficient hydraulic fluid pressure is required to operate the actuators and locks. Examination revealed a hydraulic line for the landing gear that had separated from its fitting; the separated line and adjacent wheel well area were saturated with hydraulic fluid.
Maintenance Records
The manufacturer's maintenance manual requires replacement of all rubber hydraulic lines every 1,000 hours or five years. A review of the airplane's maintenance records found no annotation indicating that rubber hydraulic lines had been replaced within that interval. Visual examination of the separated line did not conclusively determine its length of service.