B777-300
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface; Confusion
Aircraft Equipment Problem Less Severe; Deviation - Speed All Types
Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Aircraft; Human Factors
We were given a speed reduction to maintain 250 KTS speed by London. Flying in VNAV; as the speed decayed I pushed FLCH to continue our descent and capture the speed as the airplane would smoothly pitch over. The airspeed continued to decay; but the airplane did not start down; it seemed to level off. I disconnected the autopilot to arrest the speed reduction by continuing the descent. The Relief Pilot and I both noticed that the lower foot seemed excessively high. To prevent the airspeed from approaching the foot; I incorrectly called for flaps one to lower the foot. The Relief Pilot put the handle to flaps one but within a few second he stated that our altitude was too height for flaps so he re-selected flaps up. I do not believe the flaps came out. We were both distracted by what we thought to be an excessively high foot; and I was distracted further by the airplane not descending fast enough with the autopilot on and subsequently hand flying to remain within the appropriate envelope. The foot is higher at higher altitudes; but we both thought it was higher than normal. Using a Green; Yellow; Amber; Red analogy; I was not willing to let the airplane exit the Green realm and I wasn't willing to try and figure out the automation anomalies that seemed to exist. This may or may not be related however the trim setting on the close out was 6.0 and the FMC indicated 8.0 which we all three noticed as being unusually high. Not any of the three of us had seen a trim setting this high. The trim setting actually worked fine for take off; maybe better than usual. The First Officer was on break and not in the cockpit. Next time I am in this situation; I will not be so quick to try and comply with the requested speed reduction but rather coordinate with ATC to possibly delay the speed reduction or maybe take a turn if necessary. I remained well within the proper flight envelope but ATC would probably have been cooperative in delaying the speed reduction.
B777 Captain reports getting slower than desired when directed to slow to 250 KTS by ATC above FL200. FLCH is selected as the speed passes through 250 KTS; but the aircraft does not pitch over. Flaps 1 are called for then immediately retracted due to the altitude and the autopilot is disconnected and the nose pitched over manually. A high nose up trim setting on departure was thought to be factor.