Date: 201205
Local time of day: 0001-0600
Location: RJAA.Airport, FO
Flight conditions: Marginal
Light: Daylight
Aircraft: Widebody Transport
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
ATC / advisory: TRACON RJAA
Aircraft component: Autothrottle/Speed Control
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Fatigue; Distraction
Second reporter function: Relief Pilot; Pilot Not Flying
Anomaly: Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action; Flight Crew Became Reoriented; Flight Crew Regained Aircraft Control
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: While being vectored for approach; I was hand flying with the autothrottles off. As I was leveling at 9;000 and 240 KTS; we were given a runway change. I engaged the autopilot but not the autothrottles and went to the flight bag. The Copilot soon asked what was going on with the airspeed; as we were decelerating through 170 KTS; whereupon I pushed throttles to full; turned off the autopilot and lowered the nose. We lost about 80 FT and then gained the same before stabilizing again with autopilot and autothrottles back on. I'm sure fatigue from a long flight and coming off last break was a factor; but a poor excuse for not engaging the autothrottles and worse; not monitoring the aircraft. I ashamed of my performance; thankfully; the copilot saved the day.


Second narrative: On arrival into RJAA we were cleared to descend to 9;000 FT. At about 13;000 the Captain disconnected the autopilot and autothrottles and was hand-flying. The approach to 16L had been briefed previously. At about 10;000 FT; Approach Control advised of a runway change to 16R. At that time the Captain reengaged the autopilot but it was not noticed that the autothrottles were not reengaged. I was the Relief Pilot in the right jumpseat and was listening to the new approach brief over the First Officer's right shoulder. As the aircraft leveled off at 9;000 FT no one noticed that the throttles were at idle and the airspeed was bleeding off. At a point just above the yellow airspeed band the First Officer said 'what is going on with the speed?' The Captain grabbed the throttles and pushed them forward just as autothrottle wake-up was occurring. I immediately shouted 'turn off the autopilot and push the nose over;' as it appeared that the airspeed was not responding very quickly. I believe that the airspeed got about 10 KTS +/- into the yellow. The Captain turned off the autopilot and quickly recovered with only about plus or minus 100 FT of target altitude. We discussed how this happened and the Captain performed a normal approach and landing on 16R. All pilots were back on the flight deck by 45 minutes prior to landing but I do believe that fatigue was a contributing factor. Also the fact that it was smooth with relatively little pitch increase; subdued any of the normal physical cues associated with the gradual slowdown. All of these factors coupled with the runway change and subsequent re-brief led to the inadvertent lack of re-engagement of the autothrottles.


Synopsis: A fatigued crew descending into RJAA was issued a runway change and the Captain; while getting the approach chart; engaged the autopilot; but not autothrottles; so the aircraft decelerated to 10 KTS below clean maneuver speed before recovery was initiated.