B767 first officer reported encountering wake turbulence on departure from egll in trail of a B747.

Attributes
ACN	1424372
Time
Date	201702
Local Time Of Day	1201-1800
Place
Locale Reference	EGLL.Airport
State Reference	FO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb
Flight Plan	IFR
Aircraft 2
Make Model Name	B747-400
Operating Under FAR Part	Part 129
Flight Phase	Climb
Flight Plan	IFR
Person 1
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 180 Flight Crew Total 13000 Flight Crew Type 1216
Events
Anomaly	Deviation - Procedural Published Material / Policy Inflight Event / Encounter Wake Vortex Encounter

Narrative:

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).

Original NASA ASRS Text

Title: B767 First Officer reported encountering wake turbulence on departure from EGLL in trail of a B747.

Narrative: 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).

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.