FAA Aviation Maintenance Alert

Learjet: 45; Collapsing Nose Gear; ATA 3233
A submitter writes, “During a maintenance visit at our facility, a technician discovered a leaking nose landing gear actuator (P/N 6632201000-005). The facility gained access, removed and reinstalled the actuator with a repaired unit, and returned the aircraft to service.
“During an attempt to begin normal towing operations (positioning the aircraft for departure), the nose landing gear began to retract. We immediately ceased the towing operation and we were able to place a jack underneath the aircraft to support it, preventing damage.”
“...an integral mechanism holds the actuator down and locked until hydraulic pressure is applied. We suspect failure of (this) integral locking mechanism.”
(A search of the FAA Service Difficulty Reporting System (SDRS) data base revealed two similar entries for this part number.) Part Total Time: (unknown). MORE