Accident Overview
On June 14, 2018, about 0950 eastern daylight time, a Piper PA-34-200, registration N56213, was substantially damaged during a runway excursion while landing at Umatilla Municipal Airport (X23), Umatilla, Florida. The flight instructor was not injured, and the pilot undergoing instruction (PUI) sustained a minor injury. The airplane was owned by Elite Florida AC LLC and operated by Spaceport Aviation under Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the instructional flight, which originated from Space Coast Regional Airport (TIX), Titusville, Florida, about 0845, and was destined for X23.
Sequence of Events
The PUI and flight instructor reported that the flight proceeded to X23, where the downwind leg of the airport traffic pattern was extended and required before-landing checks were performed. The PUI extended the landing gear, and the flight instructor confirmed three green lights indicated all landing gears were down and locked. After touchdown on runway 01 at 80 miles per hour, the airplane suddenly began an uncommanded and violent swerve to the right. The PUI could not correct with full left brake, rudder, and aileron inputs. The airplane departed the runway and impacted a drainage ditch.
Post-Accident Inspection
While assessing the airplane with a mechanic from X23, the PUI noticed that the securing hardware for the upper and lower torque links of the right main landing gear was not in place. A Federal Aviation Administration inspector who responded to the accident site searched for the missing hardware but did not locate it. The inspector examined both disconnected torque links and found no damage to either link, nor scoring damage to the inner diameter of the right main landing gear torque link brass sleeve that the attachment bolt passes through. The brass sleeve was measured and found round and not elongated. The inspector also examined the left main landing gear and found its torque link secured with the bolt, washer, and castellated nut, but the cotter pin was missing.
Maintenance Records
A review of the airframe maintenance records revealed that during the airplane's last annual inspection, signed off as completed on May 16, 2018, new hardware was installed in both main landing gear torque links. The mechanic who signed off the inspection stated that as part of the new hardware at the torque links, cotter pins were installed. However, due to clearance issues during subsequent gear retraction testing, the hardware at both torque links was loosened to adjust each brake hose, then tightened after adjustment, but the cotter pins at both gear torque links were not reinstalled.
Preflight Inspection Guidance
A review of the airplane's Pilot's Operating Handbook indicated that the preflight inspection specified a visual inspection of the right main landing gear for leaks, the tires for inflation and wear, and the landing gear strut piston for proper extension. There was no direct mention to inspect the torque links for security.