Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 253
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Airport
After pushback; we were cleared by Ramp Control to taxi to Spot 7 and contact Ground Control. Prior to reaching Spot 7; we were unable to make contact with Ground Control and had to stop at the assigned spot. Once contact was established; Ground Control cleared us to taxi. We verified the area was clear and I attempted to taxi forward. However; the aircraft would not move forward even with the power at 40% N1 for several seconds. We verified the brakes were released and tried again; with the same result. We were apparently stuck in a depression in the pavement and; since we were reasonably certain the area around us was clear; I increased power to 50% N1; in excess of the AOM (Aircraft Operation Manual) maximum of 40%; to get the aircraft moving. The flight continued safely with no further issues.
Air carrier Captain reported pavement depression necessitated excessive thrust application to move aircraft at BOS airport.