London Heathrow – Sydney: how often flights are 3+ hours late or cancelled

Of 1,463 scheduled flights between London Heathrow and Sydney in 2025, 3.1% (95% range 2.3%–4.1%) were cancelled (23) or at least 3 hours late (about 22) — roughly 1 in 33. That is worse than 90% of 834 busy UK routes (median 1.1%). The route is 17,021 km, so when the airline is at fault UK261 compensation is £520 per passenger. This is an upper estimate: weather and air traffic control problems give no right to compensation. Source: UK CAA.

Data: CAA punctuality statistics, calendar year 2025 (published 25 February 2026) · calculated 3 November 2026 · Methodology and sources

3.1%3+ hours late or cancelled

1 in 33flights

£520UK261 per passenger if the airline is at fault

The route in 2025

Scheduled flights (both directions)	1,463
Cancelled	23
Operated but 3 hours or more late	about 22
On time or within 15 minutes	73% of operated flights
Average delay of operated flights	22 minutes
Distance	17,021 km (great circle, LHR–SYD)

By direction

Direction	Scheduled flights	3h+ late or cancelled	95% range
From London Heathrow	731	1.6%	0.9%–2.8%
To London Heathrow	732	4.5%	3.2%–6.2%

By airline

Airline	Scheduled flights	3h+ late or cancelled	95% range	Cancelled
Qantas	734	3.9%	2.7%–5.6%	11
British Airways	729	2.2%	1.3%–3.5%	12

The 95% ranges overlap, so on this route no airline is clearly better or worse than another. Airlines with at least 100 scheduled flights on the route; operating companies are shown as the CAA lists them (for example easyJet UK and easyJet Europe), because that decides whether UK261 or EU261 applies.

What you may be owed

UK261 compensation by great-circle distance; this route: 17,021 km

Distance	Delay at arrival	UK261 compensation
17,021 km	3 hours or more, or a cancellation less than 14 days ahead	£520 per passenger

Weather is a frequent reason why no compensation is due: at London Heathrow EUROCONTROL restricted arrivals for weather on 32% of days in 2018–2026.

Caveats

This is an upper estimate of flights where compensation may be due. Weather, air traffic control, strikes by third parties and security problems are “extraordinary circumstances” and give no right to compensation; cancellations announced 14 days or more ahead do not either.
The CAA measures delay at the UK airport (departure or arrival). The legal test is the delay on arrival at the final destination.
Flights in both directions are combined. For flights from an EU airport, EU261 applies when the airline is an EU airline (€250 / €400 / €600), UK261 when it is a UK airline.

CAA destination name: Sydney.