2nd of July 2021, Spontaneous Gear Collapse, Blog #710
- V2Aviation
- Jul 2
- 2 min read
This week's aviation history blog takes the reader to Paphos International Airport (PFO/LCPH) on the Mediterranean island of Cyprus, where a Cessna 750 Citation X was being prepared for a flight with two pilots and an unknown number of passengers.
After completing the required flight preparations, including obtaining their clearance to start the engines, the crew started the aircraft's engines. They were then cleared by Paphos Tower to taxi from their parking position at stand 7, via taxiways K and H to runway 29. Just after they started taxiing, still at a very low speed, when a right turn was initiated, the nose landing gear retracted. This caused the aircraft to come to a sudden stop, resting with its nose on the apron. The crew performed the necessary checklist and shut the aircraft down. Subsequently, all occupants evacuated the aircraft, and there were no injuries. Although the aircraft was taxiing at low speed when the nose landing gear retracted, the damage to the aircraft was substantial;
Nose landing gear doors and their hinges were damaged
Nose landing gear actuator damaged
The skin of the nose section buckled
The right-hand wheel-well wrinkled structure
Belly fairing damaged
Several fuselage frames were damaged
Several aileron trim and feel system components were damaged
The VHF/UHF antenna was damaged
The aircraft in its final position (©AAIIB Cyprus)
With the approval of the Cyprus AAIIB, the aircraft was lifted up, and the damaged nose landing gear actuator was replaced on the accident side. After which, the aircraft was towed to a hangar. Once in the hangar, the aircraft was put on jacks, this to facilitate retraction checks of the landing gear system. As soon as hydraulic pressure was applied to the aircraft, all landing gears inadvertently started to retract, with the landing gear control handle being in the gear down selection! This indicated that a fault existed in the landing gear logic module. Both the module and the nose landing gear actuator were sent to the manufacturer for investigation.
The Cyprus AAIIB concluded that;
The aircraft maintenance tasks in relation to the aircraft landing gear were found to be in accordance with the aircraft maintenance schedule without any omissions or unrectified defects.
The manufacturer's response to this accident was not the expected one, since long delays and pressure from the operator was needed for the manufacturer to respond.
The fact that an unsafe L/G condition existed without any warning to the crew revealed a shortfall in the landing gear design. The manufacturer evaluated the severity of this latent danger and redesigned the electrical section of the landing gear system. A mandatory service bulletin for all C750 operators was issued on the 14th of November 2022. According to this bulletin, all operators have to comply within 800 flight hours or 12 months from the day of receipt, whichever occurs first.
After temporary repairs were completed, the aircraft was flown to Athens (Greece) on the 2nd of October 2021 for permanent repairs
The Cyprus AAIIB report, which served as the source for this blog, can be accessed by clicking on the .pdf file below;
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