Introduction
On 26 March 2025, a United Airlines Boeing 767-300, registration N665UA, operating flight UA-147 from London Heathrow Airport (EGLL), United Kingdom to Newark Liberty International Airport (KEWR), United States, experienced an in-flight engine failure shortly after departure. The aircraft was climbing through FL180 when the crew reported a malfunction with the left-hand engine (Pratt & Whitney PW4060), subsequently shutting it down. A precautionary return to Heathrow was initiated, and the aircraft landed safely on runway 27R approximately 55 minutes after takeoff. No injuries were reported among the 81 occupants.
Flight and Aircraft Information
• Operator: United Airlines
• Aircraft Type: Boeing 767-322(ER)
• Registration: N665UA
• Engines: 2 × Pratt & Whitney PW4060
• Flight Number: UA-147
• Callsign: UAL147
• Departure Airport: London Heathrow Airport (EGLL), United Kingdom
• Destination Airport: Newark Liberty International Airport (KEWR), United States
• Date of Incident: 26 March 2025
• Time of Takeoff: Approx. 10:05 UTC
• Persons on Board: 70 passengers, 11 crew
• Injuries: None
• Damage: Suspected engine damage – extent under investigation
• Phase of Flight: Initial Climb
• Flight Rules: IFR (Instrument Flight Rules)
Meteorological Conditions (METAR at Time of Departure)
EGLL 261050Z 27012KT 9999 FEW030 SCT045 10/04 Q1017
• Wind: 270° at 12 knots
• Visibility: 10 km or more
• Clouds: Few clouds at 3,000 ft, scattered at 4,500 ft
• Temperature: 10°C
• Dewpoint: 4°C
• QNH: 1017 hPa
• Conditions: VMC – Visual Meteorological Conditions
Sequence of Events
1. Departure and Initial Climb
The aircraft departed from London Heathrow’s runway 27R under normal conditions. After departure, the crew initiated a standard climb towards cruising altitude. During the climb through FL180, a failure of the left-hand engine (engine #1) was detected.
2. Engine Shutdown and Emergency Decision
The flight crew promptly declared an emergency with ATC and levelled off at FL180. Following standard procedures, the engine was shut down, and the crew began preparations for a return to Heathrow.
3. Diversion and Return to Heathrow
The aircraft entered a holding pattern briefly to complete necessary checklists and coordinate with air traffic control. The crew selected runway 27R for the return landing. The aircraft touched down safely on runway 27R approximately 55 minutes after departure.
4. Post-Landing Procedures
The aircraft vacated the runway under its own power. Emergency services were placed on standby but were not required to intervene. The aircraft taxied to a remote stand where passengers disembarked normally.
Crew Actions
The crew followed all applicable engine failure protocols, including engine shutdown, configuration for single-engine flight, and fuel and hydraulic management. The decision to return was executed promptly and with coordination from Heathrow ATC. Communications remained stable throughout the event.
Preliminary Technical Assessment
While the exact nature of the engine failure is under investigation, it is confirmed that the left-hand PW4060 engine experienced a malfunction sufficient to trigger automatic and procedural shutdown protocols. There was no evidence of fire, uncontained failure, or damage to the aircraft structure reported at the time of the incident.
Post-flight inspection and data from the Quick Access Recorder (QAR) and engine health monitoring systems will be analysed by United’s maintenance teams and regulatory authorities.
Investigation and Oversight
This event has been classified as a serious incident. The UK Civil Aviation Authority (CAA) and the US Federal Aviation Administration (FAA) have been notified. As the aircraft is registered in the United States and operated by a US carrier, the FAA will be involved in collaboration with United Airlines’ maintenance division and Boeing representatives.
The investigation will include:
• Detailed teardown of the affected PW4060 engine
• Review of engine performance logs and ECAM/flight deck warnings
• Crew statements and cockpit voice recorder (CVR) data
• Maintenance history and inspection intervals of the engine
Operational Impact
• The flight was cancelled following the return to Heathrow.
• A replacement aircraft was dispatched to accommodate affected passengers.
• The incident caused minor delays at Heathrow due to ATC prioritisation.
• N665UA remained on the ground for technical inspection and engine diagnostics.
Conclusion
On 26 March 2025, United Airlines flight UA-147 returned to London Heathrow following a failure of the left-hand engine shortly after departure. The aircraft landed safely with no reported injuries, and all emergency protocols were followed correctly by the flight crew. Preliminary evidence suggests an isolated engine malfunction; however, further investigation is ongoing to determine the root cause.
Disclaimer
This report is based on publicly available information as of 26 March 2025. While every effort has been made to ensure accuracy, we cannot guarantee the completeness of the information provided. If you are the rightful owner of any referenced materials and wish them removed, please email takedown@cockpitking.com.
