How turbulent is HKG-LHR typically?

Light to moderate. The strongest chop sits near the jet core, and crews plan cruise levels around it.

What is the best altitude to avoid turbulence on HKG-LHR?

Flying above the jet core, generally FL380-FL410, gives the smoothest ride. Below it the shear is stronger.

When is the best time of year to fly HKG-LHR?

Summer and early autumn, when the East Asian jet is at its weakest. Winter brings the strongest core winds.

What causes the turbulence on this route?

Shear at the boundary of the East Asian jet stream, the strongest sustained upper wind on the planet.

Turbulence forecast HKG → LHR. Hong Kong to London Heathrow. SkyBriefing.

Hong Kong to London: what the HKG to LHR corridor looks like

Departure: Hong Kong International Airport, Hong Kong, Hong Kong SAR
Arrival: London Heathrow Airport, London, the United Kingdom
Great-circle distance: 9,631 km (5,200 nm)
Typical airborne time: 11h 42m
Usual cruise levels: FL320 to FL410
Initial track: northwest bound

Route overview

Hong Kong International Airport (HKG) in Hong Kong, Hong Kong SAR, to London Heathrow Airport (LHR) in London, the United Kingdom, is a great-circle distance of 9,631 km, about 5,200 nautical miles. At typical jet cruise speeds, and with an allowance for climb, descent and approach, that works out to roughly 11h 42m of airborne time. The great-circle track leaves Hong Kong northwest bound and spends most of the flight in subtropical air.

Leaving Hong Kong

Hong Kong International lies on reclaimed land at Chek Lap Kok with Lantau's peaks immediately south. Wind crossing that terrain creates well documented low level turbulence, and the airport has a dedicated windshear warning system because of it. The great-circle track leaves HKG northwest bound, and the first waypoint band of the flight sits close to 29.6N 85.3E. On a sector of 11h 42m, the climb to cruise takes roughly the first twenty to twenty five minutes.

The East Asian jet stream

Along the way the track passes over high latitude airspace where the polar jet stream lives. The midpoint of the HKG to LHR track lies near 36.9N 56.7E, about 4,816 km from Hong Kong, which is where the corridor spends its longest continuous stretch at cruise level. This corridor lies under one of the strongest sustained upper winds on the planet, the East Asian jet stream. Eastbound flights ride it and arrive earlier, westbound flights are routed around the core to avoid the headwind. The turbulence here is clear air turbulence generated at the jet boundary, and it is a well mapped, well forecast feature of the region.

Cruise altitudes on this sector

Ultra long sectors begin cruise lower, often near FL320 because of the fuel load, and finish two or three step climbs higher, up to FL400 or FL410. Choice of level matters because turbulence is layered: a change of two or three thousand feet often puts the aircraft into calmer air, and that is one of the first adjustments a crew will request.

Arriving into London

Approaches into Heathrow are flown along the Thames valley, often after a hold. In an active westerly the last minutes are gusty, which is routine at this airport and something crews plan a speed margin for. Descent normally begins around 44.2N 28.1E, roughly 2,408 km before LHR, and takes about half an hour from cruise level to touchdown.

Seasonal pattern

The East Asian jet stream peaks in winter and weakens through the summer, so late summer and early autumn sectors are usually the smoothest on this corridor.

Flying this route with less worry

Turbulence on this corridor is a comfort issue rather than a safety one. Airliners are certified to handle loads well beyond anything the atmosphere produces here, crews are trained for it, and the seat belt sign is the tool that keeps the cabin settled. What this page adds is knowing in advance: the map and Calmness Score above use current WAFS forecast data for HKG to LHR, so you can see what to expect before you board.