B777 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine; Maintenance Airframe
Flight Crew Total 2855; Flight Crew Type 1758
Time Pressure; Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Gate; General Maintenance Action; General Release Refused / Aircraft Not Accepted
Aircraft; Human Factors; Procedure
After Start Checklist (Flaps 5/green & both engines running) Flight Control Check -  - Control wheel rotation full (L) LEFT (with slow 6 count rate of turn) #4 vertical synoptic bar had a gap at top.  -  Control wheel rotation full (R) RIGHT (with slow 6 count rate of turn) #11 vertical synoptic bar is normal.Repeated check with same result. Also used other side MFD to be certain it was not a screen issue. We then looked at MAINT INFO Flight Control page-2. There was an imbalance between #4 & #11. Full L control wheel rotation indicated 1.23 units then 1.24 units in a subsequent check. Full R control wheel rotation indicated 1.56 units.We called Dispatch via SATCOM and conferenced [Maintenance Control]. Without hesitation [Maintenance Control] suggested to defer and stated that this was not a problem worthy of concern; but rather a synoptic display issue. I asked [Maintenance Control] if he had any numbers or parameters (units of deflection) to compare what we had vs what would be considered normal. He answered no.I knew; from past study discussion; that the purpose of synoptic display/flight control checks is to view balanced indications. I also was aware that a 'normal' #4 & #11 vertical bar synoptic should not have a space. Therefore; I immediately knew that the [Maintenance Control] response was either mistaken; negligent; or deliberately disingenuous and misleading. A concern for safety or further investigation was clearly not apparent.I gave [Maintenance Control] an opportunity to provide us with meaningful and helpful information by providing him results of not just the synoptic anomaly but also the discrepancy of the deflection (numerical units) of #4 and the imbalance between #4 & #11. Still; to no avail. Thereafter; I stated that; prior to flight; I wanted a further investigation and dialogue [regarding] the flight control matter on hand. The plane was ushered to a remote stand where maintenance boarded aircraft. The maintenance team repeated the flight control checks. One mechanic also had a printed manual in his hands. Upon performing the same check several times; the outcome was the same- they viewed exactly the same results we reported.The lead mechanic was performing the check with [Maintenance Control] apparently on his cell phone and he was speaking and taking directions in English. He then began ramming the flight controls full left apparently to 'pump' a different result. Again; to no avail.The lead mechanic; after his phone conversation with [Company] maintenance; and after viewing the aforementioned flight control check result; stated that there did not seem to be an issue. The mechanic appeared to have been directed to say this! I state this concern due to his last words on phone; in English; prior to hanging up (apparently with [Company] maintenance); 'okay; I will tell him'. He then turned to me and said that the checks are normal and within tolerance.I then glanced over at the manual the other mechanic had in hand and was reading. Interestingly; contrary to what [Maintenance Control] stated; the manual did indeed have numerical parameters for the flight controls. The numbers stated in black and white; as correct parameters; are between 1.39 to 1.77 per the manual he was reading.Additionally; 'SPOILER SYMMETRICAL PAIR 4/11 MAY NOT BE DEFERRED' was a bold headline on a different page.When I queried the mechanics [regarding] the contradiction in the directions he was told to convey to us vs the parameters we had just read in the manual the entire tone of the situation changed. Now; suddenly; maintenance called [Maintenance Control] again; and finally began the process of fixing the problem.Quite apparently; based upon the hesitation of the mechanics during their phone conversation; they were under pressure from [Maintenance Control] to undermine our concern for the safety of our ship.The flight was eventually cancelled due to the flight control conditiondiscussed in this report.
B777 Captain reported refusing the aircraft due to flight control imbalance.