Incident Details
On March 29, 2009, at approximately 1535 mountain daylight time, a Cessna Citation 550, registration N44FR, experienced a runway excursion during landing at Salt Lake City International Airport, Salt Lake City, Utah. The airplane, owned and operated by Fritzi Jet LLC, was on a business flight under 14 CFR Part 91. It had departed Great Bend Municipal Airport, Kansas, about three hours earlier. Visual meteorological conditions prevailed, and an instrument flight rules (IFR) flight plan had been filed and activated.
According to the pilot, all three green "gear down" lights were illuminated before touchdown. However, during the landing roll, the right main landing gear retracted into the wheel well, causing the right wing to contact the runway. Despite the pilot's efforts to keep the airplane on the runway, it veered right and departed the paved surface. After leaving the runway, the right wing struck runway lights, resulting in substantial damage to the leading edge and a fuel spill. When the airplane was lifted, the right main landing gear hydraulic actuator shaft was found retracted into its housing.
Post-Accident Investigation
The right main landing gear extend/retract actuator (Decoto Part Number 2-7442-2, Serial Number DA885) was shipped to Cessna Aircraft Company in Wichita, Kansas, for testing and inspection under FAA oversight. The actuator underwent radiographic inspection, load testing, external examination, and teardown. Subsequently, the components were sent to GE Aviation Systems in Yakama, Washington, for visual, dimensional, and non-destructive testing (NDT), monitored by FAA Flight Standards District Office in Spokane.
Inspection at Cessna revealed three anomalies: mis-rigging of the actuator downlock switch, worn or over-trimmed backup rings at the Lock Piston seals, and lack of required sealant at the downlock switch and visual indicator. Additionally, the safety wire on the downlock switch was missing the lead tamper-proof indicator seal. None of these anomalies was considered a clear independent initiator of the retraction.
Testing at GE Aviation Services found no issues that would impact the actuator's locking function.
Historical Maintenance and Service
Review of records showed the actuator was original to the aircraft and was removed and reinstalled for an undocumented reason on April 28, 1988, at 1,915 flight hours and 1,440 landings. On May 5, 2004, under Supplemental Type Certificate SA4954NM for increased maximum takeoff weight, the actuator's life limit was recalculated; no maintenance was performed on the actuator itself. At that time, the aircraft had 4,695 landings. At the accident, it had 5,739 landings and 7,709 flight hours. As of the report date, the aircraft had returned to service with no reported anomalies or malfunctions related to the main landing gear extension and locking.