Date: 201408
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B757-200
Operator: Air Carrier
Operating under: Part 121
Mission: Cargo / Freight / Delivery
Flight phase: Taxi
Aircraft component: Rudder Control System
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Confusion
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Taxi
Result: General Maintenance Action
Contributing factors: MEL; Procedure; Manuals; Human Factors; Company Policy; Aircraft
Primary problem: Human Factors

Narrative: As we pushed back and just after engine start; both left (L) and right (R) Yaw Damper Inoperative (Inop) lights illuminated. We accomplished the QRH procedure; called dispatch and initiated a conference call with maintenance control. While we were conferring with maintenance control; two maintenance trucks approached the aircraft. As Captain was looking up the special AOM procedure which applied to a certain number of aircraft tail numbers (we were in Aircraft X; so this procedure applies); maintenance called us over the ground to cockpit headset. I; as First Officer; told him to standby. I informed Captain X that maintenance was attempting to contact us. Captain X then called the maintenance person who was contacting us. He informed us that they were already in the Electronic Equipment (E/E) Bay of the B757 and informed us they had already 'recycled' the yaw dampers and asked if we were 'happy' with the aircraft condition at this point. Captain X asked to make sure if a write-up was required to be entered into the logbook at this time. Again they asked if we were 'happy' with the aircraft condition at that point. In accordance with Aircraft Operations Manual (AOM) Procedure XX-XX-01: YAW DAMPER INOP LIGHT(S) ILLUMINATED AFTER IRS ALIGNMENT; (B757 AIRCRAFT Line Numbers (NXX-NZZ); a procedure [has been] put in place in the AOM by our air carrier due to an 'Anomaly' that exists with the Yaw Damper Modules on these particular tail numbers (this applied to us as we were in tail (NYY). AND [also put in place] in FOM Volume-2; FLIGHT CREW HANDLING OF AIRCRAFT FOM YY-YY-04 (which applied to us as well.) We determined that this was a problem identified over time with these particular aircraft and this procedure was put in place especially for these tail numbers so as to not delay takeoff due to this 'known anomaly' once identified. After consulting these procedures we determined that we could legally depart and write-up the 'comment' prior to arrival at our destination; while enroute [as] per those procedures outlined in the AOM and FOM listed above. However; maintenance contacted us prior to takeoff via our Dispatcher to inform us that we had to return to the gate and perform a logbook write-up of the event. We asked him several times if he was asking us to return to the gate; he would not answer that; he just kept saying we had to have maintenance write-up and close-out the issue. We then opted to return to the gate to have it written up in the logbook and clarify with maintenance the procedure our air carrier had put in place (which was designed to correct and not delay the aircraft further for flight.) In reviewing what happened; I feel there is a disconnect between maintenance and the new AOM procedure. That they [maintenance] are not fully aware of this new procedure. We; as pilots; have been trained to go to the QRH and MEL to resolve such issues. This new procedure was put into the AOM with no real guidance to find it there. It is my opinion that 'NOTES' should be added to the MEL section which speaks to the yaw damper issue as well as a BOLD 'NOTE' in the QRH YAW DAMPER section of the flight controls tab of that QRH; which would aid in referring crews quickly to the new procedure should it apply to their B757 tail number. As this is a fairly new adopted procedure in the AOM; IDENTIFIED over time with these particular tail numbers on the B757 fleet; maintenance control should also be briefed on this new procedure as well; so that in the future there is no communication breakdown between maintenance control; dispatch; and flight crews regarding this unusual and new procedure.

Callback: Reporter stated Maintenance would not admit the B757 had to return to the gate since a maintenance procedure had been performed in the E/E Bay by mechanics without a write-up. Apparently; Maintenance had either re-racked or reset the L-R Yaw Damper boxes in the E/E Compartment. But that procedure was not the procedure his Air Carrier had developed and noted in their AOM. The Special Procedure in their AOM called out for the flight crew to reset the Yaw Damper Circuit Breakers (C/B) in the cockpit when the Dual Yaw Damper Inop lights illuminated on specific Boeing B757 line numbers . Reporter stated the real concern is the lack of any 'guidance' or 'reference' in their QRH or MEL procedures that should be informing flight crews about the Special Procedure in their AOM that his air carrier developed for the line number of B757s that have a Dual Yaw Damper Inop 'Anomalies' after engine starts. Becoming aware of that procedure in their AOM seems to be achieved only through 'Tribal Knowledge.' Their QRH only refers to a Left or Right Yaw Damper Inop fault after engine start; not dual failures of both yaw dampers. He was told that getting revisions to their QRH or MEL takes too much time. He does not know if their fleet engineering worked with Boeing on the issue. He and the Captain were given the flight delay; not Maintenance.



Synopsis: A First Officer reports about the lack of any 'guidance' or 'reference notes' in their QRH or MEL Manual procedures informing flight crews; Maintenance; and Dispatch that a special procedure exists in their Aircraft Operations Manual (AOM) for Dual (Left-Right) Yaw Damper Inop lights illuminating after engine starts on certain B757s.