Date: 201605
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight phase: Parked
Aircraft component: Main Gear Door
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Powerplant; Maintenance Airframe
Human factors: Situational Awareness
Second reporter function: Technician
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
Result: Aircraft Aircraft Damaged
Contributing factors: Manuals; Procedure
Primary problem: Manuals

Narrative: The Aircraft was in for Service and an A check inspection. The LH MLG (Main Landing Gear) door hinge bushing had been written up for excessive play so the door needed to be removed for bushing replacement. I went to the aircraft and inspected the LH gear so it could be retracted to aid in easier removal of the LH MLG door. I called over a technician to assist me by holding the door during retraction. We both looked at the gear linkage and all the hardware was secure and the bell crank appeared to be in the correct position for gear retraction. The door was disconnected previously at the bellcrank on the door strut attach side. I went up into the flight deck and powered the aircraft and pressurized hydraulics. I raised the gear handle and the LH gear began to retract. A short time later before the gear was fully retracted I heard a whistle followed by the technician saying 'Gear Down'. I immediately returned the gear handle to the down position; waited for the gear to extend; depressurized the hydraulics and went to investigate the problem. When I arrived at the LH gear bay we found that the airframe to bellcrank linkage was broken. Upon further investigation we noted that the bellcrank had rotated backwards during retraction and caused the linkage to break and be pressed up into the up-lock assembly support frame area of the fuselage causing a dent and tear in the structure.In the maintenance procedure CRJ 200 AMM 32-12-00 for retracting the gear; with the door disconnected; it states to disconnect the door in the location that the door had been previously disconnected. There is also a caution in the section that states to make sure the bellcrank is overcenter to avoid damage to the aircraft. Both myself and another technician looked at the bellcrank and determined that it appeared to be in the correct position for retraction. During the retraction of the gear the bellcrank rotated backwards and caused the damage to the aircraft explained above. The Aircraft Maintenance Manual (AMM) needs to be revised showing an image of what you should expect to see for the note that says the bellcrank needs to be overcenter. It doesn't explain overcenter which way or how it should look overcenter. I don't believe this would have occurred if there would have been a better explanation of which position the bellcrank should have been in to avoid damage. Both I and the other technician are experienced mechanics and we both had determined at the time in our best judgment that it was in the correct position for retraction.


Second narrative: On the hangar floor; I was asked to assist my coworker in retracting the gear for gear door work. We both observed bellcrank and arm; discussed it and came to the conclusion that when the gear retracted; we should achieve correct overcenter of the bellcrank and there would be no problem. I held the door open and my coworker put the gear up. All appeared normal until I heard a snap which was followed by the gear stopping short of being fully stowed. Blew whistle and yelled for gear down. Gear came down without incident. Then noted broken door arm and damaged airframe.MLG did not retract completely into the wheel well...Unfamiliarity with gear door direction of actuation.Whenever CRJ 200 MLG is retracted with the door disconnected; Door rods and bellcrank should be completely removed for the airframe and gear and left only attached to the gear door; No room for error if that action is taken.


Synopsis: Two maintenance technicians reported that while retracting the Main Landing Gear on a Bombardier CRJ200 for maintenance; with the MLG door disconnected; the bellcrank was out of the proper position causing the linkage to break and damage to the aircraft.