Flight EI-911, an Airbus A320 jet, spent over an hour in the skies over the south east of Britain before the crew finally diverted and landed at Heathrow just 40 kilometres from Gatwick where the flight had originated.
The control tower at Gatwick Airport was struck by lightning during the storms which swept across the area. However, Aer Lingus said flight 911 was not hit by lightning and diverted to Heathrow because of bad weather.
The airline confirmed, however, that the same aircraft was involved in a suspected birdstrike while on approach to Heathrow and was grounded for several hours as a result.
Flight EI-911 departed from Gatwick Airport at 1.14pm on its 90-minute flight to Ireland West Airport in Knock, Co Mayo. The jet first routed north over Central London before turning south again.
For the next hour, the crew flew in patterns over the south east of England, as far south as Dover and the English Channel, before diverting to Heathrow Airport. The jet had reached a height of 31,000 feet before it had to descend again.
The jet touched down safely at around 2.43pm, about the same time it would have been scheduled to land in Knock. The plane was immediately grounded after the crew reported a birdstrike shortly before landing.
While engineers inspected the aircraft, the 99 passengers on board were accommodated on flights to Shannon and Dublin from where they were taken onto Knock by road.
A spokeswoman for the National Air Traffic Services (NATS) in Britain said: “We do not comment on incidents involving airlines but one part of our system was knocked out for about 10 minutes by the lightning but this had a minor effect on operations. The main reason for the delays was the thunderstorms which the pilots wanted to fly round rather than through.”