TUI flight aborted mid-air as passengers faced risk of life-threatening ...

A TUI flight was aborted mid-air over Lincolnshire after a drop in cabin pressure exposed passengers to the risk of a potentially life-threatening condition. The Boeing 737-8K5 plane was carrying 193 people, including passengers and crew, when it took off without a crucial check which meant the aircraft failed to pressurise.

An investigation was conducted by the Air Accidents Investigation Branch (AAIB) into the flight which was due to fly from Manchester to Kos on October 17, 2023. The report published in November 2024 found that the aircraft departed with the engine bleed air system switched off because the switches had been incorrectly left off following maintenance activity the night before - and they had not been turned back on during pre-flight procedures.

The incorrect switch selection went undetected by the pilots and it was found that they did not complete correct protocols in response to a cabin altitude warning, which remained illuminated for 43 minutes during the flight. The pilots turned the switches back on mid-flight, but a further warning prompted them to seek advice from bosses on the ground and the flight returned to Manchester, having only reached the North Lincolnshire coast.

The aircraft did not pressurise, meaning the crew and passengers were exposed to the risk of hypoxia. As the cabin altitude was below 14,000 ft, the likelihood of loss of consciousness was very small without the pre-existence of significant medical issues. However, the report also states that the hypoxic exposure could have been sufficient to affect decision making.

A section of the report reads: "If the aircraft had continued to climb, the aircraft's passenger oxygen system would have deployed automatically when the cabin altitude reached 14,000 ft." It adds: "As progressive exposure to hypoxia increased, the likelihood of the crew taking correct recovery actions would have decreased."

As the aircraft was above maximum landing weight, the crew had to enter a hold with the landing gear extended to burn fuel and reduce weight. The situation was explained to the passengers over the public address system. TUI has been approached for comment.