Regional Jet 700 ER/LR (CRJ700)
Maintenance Airframe; Maintenance Powerplant
Communication Breakdown; Confusion; Situational Awareness; Time Pressure; Troubleshooting; Workload
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; Manuals; Procedure
An assistant and I were sent on a roadtrip to ZZZ for a pitch/feel fault on the aircraft. When we got to the aircraft we called maintenance control to let them know we were at the airplane. We asked them where they wanted us to start; and they said to check the MDC (Maintenance Data Computer). Upon interrogation of the MDC; we found 3 faults that were in the history that included data loss/lost connection in the Stabilizer Control Unit (SSCU); but no current faults. These faults were: SSCU 1 OFF/NO OUTPUT; SSCU 1 FAILED/INTERNAL FAULT CHANNEL A; and PITCH FEEL ACT 1 141 MOTOR-NO RESPONSE TO CMD. After checking the detailed description for each fault; there was an obvious connection between all faults. The Fault Isolation Manual (FIM) confirmed that the first step for 2/3 of the faults was to change SSCU 1. The third FIM reference had it listed second; after an ops check of the pitch/feel actuator. We proceeded to remove and replace SSCU 1; and ops checked it an excessive amount of times; which resulted in zero failures. My assistant and I signed the write up off with removing and replacing SSCU 1. We called MX control to tell them that the aircraft was fixed; and we were told that we had to change the linear actuator. When I questioned MX Control; we were told (after 20 minutes of arguing) that the decision had been made by the Supervisor; even though there were no faults present; and nothing in the history suggesting a bad actuator. After my assistant and I removed the existing actuator; we realized that we didn't have the power supply we needed to rig the new actuator. At this time we called MX control to notify them. MX control called back minutes later; suggesting that we disconnect the aircraft's main battery and use that as a power supply. When we refused to do it in that particular unsafe manner; we were told to remove a circuit breaker from the circuit breaker panel in the cockpit and wire it in series with our actuator. Once again; we refused. Our controller explained to us that he talked to a lead in the hangar; and that this particular way was an accepted practice. We continued to refuse; until eventually our controller called his supervisor and set up a charter flight to deliver our power supply. Today I discussed this experience with an experienced avionics technician; and I realized the danger we could've been put in; had we followed what our controller said. Also; I feel it was completely unnecessary to even be touching the linear actuator; after the troubleshooting we did. Every conversation my assistant and I had was over maintenance control's recorded phone line. I would suggest these tapes be pulled to review the overall judgement made by our controllers and their supervisor. I have been notified that we were sent down there to change the linear actuator. This can be disproved by the initial conversation we had with maintenance control; and the faults listed/Fault Isolation Manual references we used; which are all on the audio recordings. All events described happened as a result of performing unnecessary maintenance; at an outstation; with inclement weather and limited tools.
Reporter stated that the Pitch/Feel system was repaired after replacing the #1 Stabilizer Control Unit (SSCU) no more faults were found. Maintenance Control insisted on changing the Linear Actuator which requires a variable power supply to properly rig the actuator. There was no power supply available; so Maintenance Control advised to use the aircraft battery as a power supply. The reporter refused to comply until a proper power source was available. The proper power was flown in so the job was completed per the Maintenance Manual. The reporter stated that the replacement and a second actuator failed. Not until a third actuator was installed was the system repaired.
After troubleshooting and replacing the #1 Stabilizer Control Unit on a CRJ-701 Maintenance was told to replace the Linear Actuator for the Pitch/Trim system. Before installing the replacement actuator it had to be sequenced and rigged using a variable power supply. Since they didn't have one available; Maintenance Control told the maintenance crew to use the battery on the aircraft as a power supply. Maintenance refused until the proper power supply was available.