‍DALLAS— On March 20, a fire at the electricity sub-station at Hayes on North Hyde Gardens led to a major power outage at London Heathrow Airport (LHR), prompting airport authorities to shut down operations for safety reasons. This has left passengers stranded and airlines scrambling to reroute flights. As a result, the airport will remain closed until 23:59 on March 21, 2025.

According to the Guardian, counter terror police lead the investigation into the never-before-seen electrical substation fire that has halted more than 1,300 flights while engineers try to restore power today. LHR connects to over 80 countries and can handle almost a quarter of a million passengers on a daily basis.

Authorities are urging passengers to avoid traveling to LHR until operations resume. Travelers should check with their airline for the latest updates regarding their flights.

OAG Quick Facts

Here are a few quick stats on LHR from OAG data:

• LHR is the largest European airport based on seats (4,296,701 scheduled for March 2025), the 5th largest airport in the world and the 2 largest for international capacity.
• There were 1,332 flights scheduled for today, March 21, 2025, and all have been cancelled.
• British Airways (BA) is the operator of 51% of those flights.
• Over 5,300 seats were planned to New York JFK, 4,500 to Dubai and 3,000 to Frankfurt.
• The smallest route impacted was to the Isle of Man with 72 seats.

Flight Diversions, Cancellations

Around 120 flight were inbound when the shut down was announced. With LHR unavailable, multiple flights en route to Europe's main hub were forced to divert to alternate airports, including:

• Bangor (BGR)
• Goose Bay (YYR)
• Amsterdam (AMS)
• Paris (CDG)
• London (LGW)

Additionally, several flights returned to their points of origin, affecting major hubs such as:

• Dallas/Fort Worth (DFW)
• Miami (MIA)
• Chicago O’Hare (ORD)
• New York JFK (JFK)
• San Francisco (SFO)
• Newark (EWR)

Summary of Flight Disruptions at LHR (March 21-22, 2025)

The following breakdown is from data gathered from aviation analytics company Cirium:

Flight Schedules

• Today (Friday, March 21, 2025)
  • Departures from LHR: 665 flights, 145,094 seats
  • Arrivals to LHR: 669 flights, 145,836 seats
  • Most flights/seats from: New York-JFK (21 flights, 5,387 seats)
  • Other major origins: Dubai, Dublin, Frankfurt, Doha, Munich, Los Angeles, Madrid, Delhi, Geneva, etc.
• Tomorrow (Saturday, March 22, 2025)
  • Departures from LHR: 615 flights, 136,951 seats (slight reduction)
  • Arrivals to LHR: 604 flights, 134,726 seats
  • Ongoing disruptions are expected as aircraft, crew, and passengers are displaced.

Disruptions & Assumptions

• It is assumed that all scheduled flights to/from LHR today are canceled, affecting North American flights arriving on Saturday.
• Airline feeds may not be fully updated, affecting real-time data accuracy.

Diversions

• Multiple long-haul flights to LHR were diverted to alternative airports.
• Airlines affected: American Airlines, Air Canada, Air India, JetBlue, British Airways, etc.
• Major diversion airports: BOS, YYR, JFK, ORD, MIA, LAX, YYC, DEL, VIE, FRA, MUC, CDG, MAD, AMS, MAN, GLA, etc.
• Notably, BA flights from New York, Los Angeles, Johannesburg, and Sao Paulo were redirected.

This disruption is expected to cause significant cascading effects over the coming days due to limited aircraft and crew availability.

So far, investigators have stated that there was "no indication of foul play."

UPDATE

London Heathrow has announced via X that it can “now safely able to restart flights” and plans to “run a full operation” on Saturday, though it warned to not travel to the airport unless airlines advised to do so.

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