B767 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 180; Flight Crew Total 13000; Flight Crew Type 1216
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Wake Vortex Encounter
General None Reported / Taken
Procedure; Environment - Non Weather Related
Two and a half minutes after a B747 was cleared for takeoff; we were cleared for takeoff on 9R at EGLL. We were cleared to LON 2.0 DME; then right heading 220 to climb and maintain 6000 ft. After takeoff; we were cleared to continue right turn to 250. At 2100 ft MSL; we encountered the wake of the preceding B747-400. It was 'moderate' by the coffee spill criteria and short-lived (3 seconds). It was only one encounter. It was while we were in 25 degree right bank and we probably got additional 10 degree right/left/right with associated yawing and some pitch (+/-5 degree?); airspeed probably +/- 10 KIAS (from 200 KIAS and accelerating during flap retraction). Nevertheless; it was a 'little wake; huh' type of encounter that was mitigated by everyone being in seat belts and down (flight attendants). Winds on surface were east at 10-15 knots. My guess is that the B747 flew a wider turn. It was definitely smooth until the encounter and smooth afterwards (not much; if any; ambient turbulence). I am not sure what winds were at 2000 ft. We reported the wake encounter to tower controller before we were handed off to next frequency (about 2700 ft MSL).
B767 First Officer reported encountering wake turbulence on departure from EGLL in trail of a B747.