A Boeing 737 TUI with 187 passengers suffered a “serious” incident | United Kingdom

The report says the TUI passenger plane was flying over the Humber area when it suffered a “serious incident”, just three days before the same plane suffered an unrelated “catastrophic failure” on landing at Lees Bradford Airport.

A new report published by the Air Accident Investigation Branch looks at an incident in North Lincolnshire. The Boeing 737-8K5 took off from Manchester Airport shortly after 6:00 a.m. on October 17, 2023. There were 187 passengers and six crew members on board – no one was injured in the incident. The plane landed safely in Manchester at 8.10am.

Just minutes after takeoff, a cabin altitude warning alerted the pilot to a cabin pressure failure during a flight to Kos Airport, Greece.

The “major incident” report said: “Both engine bleeding systems were inadvertently disabled for departure, and as a result the aircraft failed to build up pressure.”

Engineers reportedly turned off the systems during previous maintenance but did not turn them back on during a pre-flight inspection of the plane.

The crew turned both systems back on and, believing the problem had been resolved, continued flying higher into the sky. However, during the climb, the main warning light came on, indicating a fault. The commander decided to return to Manchester Airport for safety reasons after consulting the operator’s technical service department.

Because the plane was too heavy to land, it had to go into the cargo hold to burn fuel and reduce the plane’s weight. The crew failed to perform their prescribed exercises in response to the cabin altitude warning – such as wearing oxygen masks – which was on for 43 minutes. Hull Live reports.

The report described the risk of hypoxia, or low levels of oxygen in the blood, stating: “Because the aircraft was unpressurized, the crew and passengers were at risk of hypoxia. At cabin altitudes above 3,000 feet but below 14,000 feet, without serious health problems, the likelihood of loss of consciousness is very low.

“However, within this altitude range, hypoxia exposure may be sufficient to impact cognitive performance and decision-making to the point that the decline is noticeable on tests of cognitive function.

“Within this altitude range, there are many variables that influence the severity and effects of hypoxia, including duration of exposure, rate of onset of hypoxia (e.g., rate of ascent if unpressurized), physical load, fatigue, individual responses, and the type of task being performed. done.

“In this altitude range, it is also difficult to separate the relative contribution of hypoxia from other factors that impair performance, such as fatigue, distraction, or other human performance problems.”

The report said the plane’s climb was interrupted by an air conditioning fault. It said that if the plane continued to climb, “the aircraft’s oxygen system would automatically activate when the cabin altitude reached 5,000 feet.”

Upon reaching a cabin altitude of 5,800 feet, the Master Automatic Pressurization Failure warning will be activated. The report added: “As progressive exposure to hypoxia increases, the likelihood that the crew will take appropriate corrective action would decrease.”

The report also noted that the pilots were not originally scheduled to fly the plane and went off standby duty at 3 a.m. The commander, who was woken at 1 a.m. by a notification on his smartphone registration app indicating he had been assigned to a flight from Manchester to Kos, had only slept three hours the night before because he had completed a “significant amount of overtime duty” over the past eight weeks.

The co-pilot was notified by telephone from the crew at 2:30. Both pilots received their reporting time at 4:30.

The report said that while they were not necessarily individually tiring, cumulative disruptions may have had an impact. It read: “Although the commander did not believe that fatigue was a factor in this incident, an analysis of his schedule in the eight weeks leading up to the event and the rest period immediately prior to it suggests that fatigue may still have been a contributing factor. This should happen. It is important to note that fatigue, especially chronic fatigue, can be insidious and result in a person not recognizing the symptoms.”

Three days after the incident, the same plane missed the runway while landing amidst Storm Babet at Leeds Bradford Airport. Although the plane suffered minor damage, no one on board was injured.

TUI has been contacted for comment.