British Airways and extraordinary circumstances

The causes British Airways relies on

Heathrow. BA operates the largest schedule at an airport that runs near capacity, so air-traffic-control flow restrictions, runway incidents and weather (fog, wind limits, snow) are real and recurrent. They can be extraordinary — ATC and weather are the textbook cases — but each one has to be shown for your flight: the restriction reference, the time it applied, and why no other aircraft, slot or route was available once it lifted. When the NATS air-traffic-control system failed on 28 August 2023, the failure itself was outside BA’s control; the days of knock-on cancellations that followed were judged flight by flight on what BA could reasonably have done.

Inbound aircraft. “Late arrival of the operating aircraft” is the most common BA delay reason and the weakest defence: a rotation delay inherits the status of its original cause. A morning ATC delay at Heathrow does not make the evening’s fourth sector extraordinary if BA had the day to recover with a spare aircraft or crew from its own base.

BA’s own IT. BA’s booking, check-in and operations systems have failed on several occasions, most visibly in May 2017 when its network stopped for days. Courts and CEDR treat an airline’s own systems as inherent in running an airline; these failures are not extraordinary.

Strikes by BA staff. Pilot strikes (BALPA, September 2019) and cabin-crew disputes are internal. Under Krüsemann (retained case law) and the Airhelp v SAS reasoning (2021, persuasive in the UK), they are within the airline’s control. BA contests this in the UK; CEDR decisions have gone both ways depending on the facts, so a strike claim should cite the reasoning and expect to be escalated. Strikes by Heathrow security or baggage staff, or by air-traffic controllers in France, are external and usually extraordinary.

Technical faults and crew. Never extraordinary, however sudden: hydraulic, engine and cabin-pressure faults, crew reaching duty-time limits, crew sickness.

What you keep whatever the cause

Refund or re-routing, meals, a hotel when the wait runs overnight, and two calls or e-mails — Articles 8 and 9 have no extraordinary-circumstances clause. If BA tells you to arrange your own hotel, keep the receipt and claim it through BA’s expenses form.

How to test a British Airways “extraordinary circumstances” answer

1. Ask BA in writing for the specific event, evidence it affected your flight, and the measures it took to avoid the delay.
2. Compare with what you can see: flight-tracker history for the same route that day, the airport’s own notices, weather archives.
3. If the answer is generic or internal, escalate to CEDR — BA carries the burden of proof there too. The extraordinary circumstances page lists every cause with the case that decided it.

The legal test

Article 5(3) of Regulation 261/2004 (UK261) excuses British Airways from paying compensation only if it proves two things: that the disruption was caused by extraordinary circumstances — an event that is not inherent in the normal exercise of an airline’s activity and is beyond its actual control — and that it could not have been avoided even if all reasonable measures had been taken. Both limbs are for British Airways to prove, for your specific flight.

Usually extraordinary

• Severe weather at the departure, arrival or en-route airports that actually prevented the flight.
• Air-traffic-control restrictions, capacity regulations, ATC system failures and ATC strikes, for the flights they held.
• Airport closures, runway incidents and security threats.
• Bird strikes (Pešková) and foreign objects on the runway.
• Strikes by third parties outside British Airways’s control (airport staff, ground handlers not employed by British Airways, ATC).

Usually not extraordinary

• Technical faults discovered during maintenance or on the day (Wallentin-Hermann, van der Lans), other than hidden manufacturing defects or sabotage.
• Crew shortages, crew sickness and crew running out of legal duty hours (TAP C-156/22).
• Strikes by British Airways’s own pilots, cabin crew or ground staff, including wildcat strikes (Krüsemann, Airhelp v SAS).
• Aircraft rotations and late inbound aircraft, unless the first delay itself had an extraordinary cause.
• British Airways’s own IT systems failing, schedule changes and over-booking.

Reasonable measures

Even for a genuine extraordinary event, British Airways must show it did what a reasonable airline would: used spare aircraft or crew where it had them, re-routed you at the earliest opportunity including on other airlines, and did not cancel the next day’s flights merely to reset its schedule. A knock-on cancellation hours after an ATC restriction lifted is where this limb most often fails.

What to ask British Airways

Ask for the specific event, its time and place, whether it applied to your flight rather than the day in general, and what measures British Airways took. Keep the answer: it is the evidence CEDR or a court will assess. Refund, re-routing and care are owed in every case — extraordinary circumstances only ever affect the £220, £350 or £520 compensation. The general rules, with the case law cause by cause, are on the extraordinary circumstances page; ATC reasons are tested on the air traffic control page.