B747-400
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 160; Flight Crew Total 22500; Flight Crew Type 8700
Aircraft Equipment Problem Critical
Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
During climb I felt the aircraft needed more trim inputs than usual. At level off I decided to check the maintenance display page for flight controls to make sure the trim settings and spoiler positions were normal. That is when I discovered that the aileron wheel input showed 29.4 units of aileron wheel to the right. Maintenance Control and Dispatch were consulted. The flight deck crewmembers; Dispatch; and Maintenance agreed that the safest thing to do was to return to our departure airport. Fuel was dumped enroute and we made an uneventful landing at about 626;000 LBS. Fuel jettison began at XA30Z at FL320 [and] fuel jettison terminated at XB15Z at FL230.
A B747-400 Captain experienced unusual trim requirements during the climbout. A review of the Flight Control EICAS display page revealed the existence of 29.4 units of right aileron trim. After dumping fuel the flight returned to their departure airport for maintenance.