Accident Overview
On June 17, 2010, at 1135 eastern daylight time, a Champion 7ECA, registration N73PC, operated by N117VR LLC as a 14 Code of Federal Regulations Part 91 personal flight, experienced a right main landing gear oleo strut separation during a wheel landing at Thomasville Regional Airport (TVI), Thomasville, Georgia. Visual meteorological conditions prevailed, and no flight plan was filed. The aircraft sustained substantial damage. The commercial pilot reported no injuries. The flight originated from Merritt Island Airport, Merritt Island, Florida, at 0820.
Pilot Account
The pilot stated that upon arrival at TVI, he made a radio call on the common traffic advisory frequency and announced his entry into the traffic pattern for runway 04. He completed all before-landing checks, slowed the airplane to 65 mph on final approach, and performed a wheel landing. As soon as the main landing gear touched down on the runway, he heard a "pop" or "snap" sound. The airplane then collided with the runway on its right side and slid down the runway until it came to a stop.
Examination Findings
Examination revealed structural damage to the right main landing gear attachment point on the fuselage. According to the Federal Aviation Administration inspector and an airframe and power plant mechanic who inspected the landing gear, the bolt that held the oleo unit in the housing was installed above and through the oleo assembly, which eventually allowed the bolt to fall out of the housing. The oleo (part number 3-665) on the right side failed internally, allowing the cylinder and spring to overextend out of its housing. No evidence of fatigue, stress, or corrosion was found on the failed component.
Maintenance History
Review of the airframe logbook showed the last annual inspection was conducted on May 4, 2010, at a tachometer time of 1,353.66 hours. The aircraft had flown 3.8 hours since that inspection. The mechanic who performed the last inspection stated he did not perform any maintenance on the right main landing gear. The previous annual inspection was conducted by a different mechanic on December 10, 2007, at a tachometer time of 1,289 hours. That mechanic indicated that the seals were replaced in the oleo main gear. The aircraft had accumulated 69 hours since that inspection. Attempts to locate that mechanic were unsuccessful. No work was performed on the landing gear during the annual inspection conducted on August 12, 2006.
The Citabria Maintenance Manual and Parts Manual for the landing gear group states for the oleo piston assembly: "This assembly consists of spring, plunger, and hydraulic oil retaining cylinder....If it is necessary to change the graphite packing, release oleo unit from the oleo case assembly by removing the bolt at the top of the oleo case. Drive bushing out of spring retaining washer and remove retainer and oleo spring. Pry the plug at the top of the cylinder loose and remove old packing. Press the new into place around the piston rod and replace parts. Extreme care should be taken in replacing the oleo in the old case. Be certain that the bolt passes through the retainer at the top end of the oleo. If this is not done, the oleo will fall out when the aircraft takes off."