Date: 201309
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Light: Night
Aircraft: Regional Jet 700 ER/LR (CRJ700)
Operator: Air Carrier
Operating under: Part 121
Flight phase: Other During Maintenance
Aircraft component: Fan Blade
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Airframe; Maintenance Powerplant
Human factors: Communication Breakdown; Situational Awareness
Second reporter function: Technician
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Other During Engine Runs
Result: Aircraft Aircraft Damaged; General Maintenance Action
Contributing factors: Chart Or Publication; Human Factors; Procedure
Primary problem: Human Factors

Narrative: After a [GE CF34-8c engine] Fan Pin change; the CRJ-700 [aircraft] was pulled from hangar for engine runs. After the required idle time [run]; the throttle was advanced and that's when the vibration indicator went to 1.2; the damage was done. It occurred about XA:30AM; September 2013. I was Left (LT) seat; Mechanic Y was Right (RT) seat. Procedure was not followed. [Recommend] making it a Quality Control (QC) Inspection 'Buy Back' for tool removal on Work Card. Graveyard.


Second narrative: Regarding an incident occurring September 2013; at approximately XA:00 A.M. which involved the Right Engine on a CRJ-700 aircraft. I had performed a Fan Blade Pin change on the Right Engine in accordance with the appropriate Work Card. When all other work had been completed by other members of the assigned crew; Mechanic X and I; [Mechanic Y]; took the plane out for the Engine Vibration Check. Mechanic X sat Left seat and I was Right seat. Mechanic X started the Right Engine first; as it was to idle for five minutes before testing. We taxied the aircraft to the testing ramp and after the required time had elapsed we began the test by increasing the engine speed to full power. All indications up to this time had been normal registering a vibration between 0.1 and 0.2. After several seconds at full power; the vibration began to very quickly increase to 1.1 at which point Mechanic X decreased power back to idle. The indicated vibration returned to a normal 0.1 to 0.3. After allowing the engine to stabilize at idle for several minutes he attempted to increase power once again. This time the vibration level climbed excessively along with the speed of the engine. We decided at this time to return to idle speed and return to the hangar to determine the problem. Upon arrival at the hangar it was discovered that extensive damage had occurred within the engine. I very quickly went to my tool box and discovered [that] a ratchet I had been using to perform the pin change was missing. I then went to the acting Supervisor's office and reported the damage and my missing tool.  Several factors may have contributed to this incident. It was very early in the morning; on my first day back to work after my three days off. This is a job I have performed often; overconfidence; or complacency may have figured in. Tools should be inventoried and accounted for before an incidence occurs not after. To prevent it from happening again; make absolutely sure someone else checks behind you; especially if you are tired. Graveyard [shift].


Synopsis: Two Aircraft Maintenance Technicians (AMTs) report about extensive damage that occurred to the Right Engine of a CRJ-700 aircraft during full power engine runs; after a Fan Blade Pin change had been accomplished on their GE CF34-8C engine. One of the Technician's later realizes a ratchet used to perform the pin change was missing.