B747-400
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Aircraft Aircraft Damaged; Flight Crew Regained Aircraft Control
Aircraft
We back taxied down runway XXL/XR; did a 180 and held on XR awaiting takeoff clearance. Weather was clear with very light winds. Takeoff roll was commenced. Takeoff weight approximately 308; flaps 20; derate 2; NADP (Noise Abatement Departure Procedure) 2. Clearance to 9;000 feet; direct to ZZZZZ. Normal takeoff until after V1; and about ten knots prior to rotation; the right wing started to rise. I was confused at first and thought that a crosswind had come up. Continuing the rotation; I had to apply nearly full right aileron to maintain directional control. At first I thought we had lost an engine; checked for yaw; and seeing none called for the synoptic. Nothing. The aircraft continued to try and roll left; but we were able to maintain directional control straight ahead. Some rudder was required. At 1;000 feet; we pitched over to accelerate for flap retraction. At approximately flaps ten to five; there was a 'pop' sound and control started to appear normal. At flaps up; directional control was normal. I accelerated to around 260 knots; held that speed until I stopped climb at 15;000 feet after being cleared to FL350. That was so we could take the time to assess the situation and make decisions. The three maintainers went downstairs and reported to us that there was some damage to numbers 5 and 6 spoilers; but everything appeared to be mostly intact. I checked controllability; which was fine. Quickly on departure; [the First Officer] checked our control surfaces on the status page for abnormalities; they were fine. After confirming with everyone that the aircraft was flyable; I elected to continue. I called Operations about 25 minutes into the flight to advise them of the situation and if I came back; which airport would be preferred. I also asked for no flap data if in case that was the problem. But not thinking it was; I elected to continue on to [our destination]. They had a long runway and the weather was fine. We also asked if any debris was found on the runway. Later we found out that there were four panels found near the runway. Anyway; after a scare with a fuel imbalance on 2 and 3 almost immediately after takeoff; we determined that that there was no leak in tank 2; just a system hiccup. So we pressed on; but continued to look at fuel possibilities; and discuss configuration possibilities. We elected to not use speed brakes on descent in case it was a spoiler problem; to get an extended final; and configure early to do controllability checks. I elected to do a flaps 25; autobrake 4 landing on 4R. As flaps went from ten on to twenty five; controllability degraded again; but were doable. Per somebody's suggestion; I disengaged the autopilot early so as not to have a surprise later. Hand flown ILS to touchdown; then speed brakes were deployed automatically. No issues; and normal rollout ensued. I elected not to retract the flaps; and per Maintenance's suggestion; I selected flaps thirty just prior to block-in. Only after shutdown and post flight inspection did we realize the damage to the flaps and aircraft in general. Quite a surprise to say the least.Cause: Aircraft aging.Suggestions: If I had known the extent of the damage; I would have dumped fuel to 20K and done a no to ten flap landing in ZZZ. But I just thought it was a spoiler problem from what I could tell (see). Hindsight is 20-20. I would like to extend kudos to Dispatch and Operations; they were very helpful. But the no flap data was pretty slow in coming; although we figured it out pretty quickly ourselves from the QRH data section. Glad to be in one piece. And fatigue seems to becoming more of a problem on these aircraft. Maybe we should start limiting the practice of max takeoff and max landing weights to give them some relief.
B747-400 Captain reported having trouble controlling the aircraft during takeoff.