A United Airlines flight bound for New York was forced to declare an emergency and return to London Heathrow Airport this afternoon after smoke was reportedly seen filling the cabin mid-flight.

Flight UA147, a Boeing 767-300 carrying 70 passengers and 11 crew, took off from Heathrow at around 3.45pm, en route to Newark Liberty International Airport. However, shortly after takeoff, the aircraft was seen looping over Kent at around 13,000 feet, before performing a U-turn and heading back to Heathrow.

The incident was quickly picked up by aviation tracking site Flightradar24, which flagged the aircraft in red as it broadcast the emergency transponder code 7700, indicating a general emergency.

Smoke in the Cabin Sparks Alert

While United Airlines cited a “potential mechanical issue”, sources report that smoke was visible in the cabin, triggering alarm among passengers and prompting the crew to take emergency precautions.

Safe Landing and Investigation Underway

A live stream captured the moment the plane touched down safely at Heathrow. Emergency services were on standby as the aircraft landed. All passengers were safely disembarked, and no injuries have been reported.

A United Airlines spokesperson confirmed:

"United flight 147 returned to London Heathrow Airport to address a potential mechanical issue. The flight landed safely and was subsequently cancelled. We are working to rebook customers on the next available flight to Newark."

Flight Path Tracked by Thousands

At one point, over 10,000 people were tracking the aircraft’s unusual flight path online, as it circled over the Ashford area and southern Kent before heading back west. The aircraft involved was identified as Boeing 767-300, registration N665UA, built in July 1998.

A spokesperson for Heathrow Airport confirmed the emergency landing and added that all passengers were safely evacuated.

The Civil Aviation Authority (CAA) declined to comment while investigations into the incident continue.

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