### Midair Mechanical Error Forces Tui Airways Flight to Abort Journey

A Tui Airways flight filled with holidaymakers from Manchester, UK heading to Kos, Greece, had to turn back due to a technical issue that caused the plane to lose cabin pressure. An investigation by the Air Accidents Investigation Branch (AAIB) revealed that the 193 passengers aboard faced a potential risk of hypoxia.

The probe into the incident, which occurred last year, discovered that bleed air switches, responsible for regulating cabin pressure, were left in the off position after maintenance work on the aircraft's air conditioning system. This oversight, made during preflight safety checks, led to the pressurization failure.

Maintenance engineers involved in the pre-flight checks had assumed the switches had been returned to the correct position. One engineer thought the switches had been reset, while another failed to notice they remained off. This error was also missed by the flight crew during preflight and after takeoff checks.

Upon realizing the issue, the pilots switched the bleed air switches back on. However, according to the AAIB report, they did not take additional steps outlined in the Quick Reaction Handbook (QRH), such as donning oxygen masks, which would have provided immediate protection from hypoxia.

The crew believed that turning on the switches would rectify the problem and considered further actions unnecessary. Nonetheless, wearing the oxygen masks would have safeguarded the pilots until the situation was fully understood. Despite the switches being reactivated, a warning signal persisted for 43 minutes before the crew contacted Tui's maintenance team at Manchester Airport. The captain then opted to return the aircraft to Manchester.

Cerebral hypoxia, a condition where the brain is deprived of oxygen, can be caused by various factors, including high altitudes or cabin pressure loss. According to the Federal Aviation Administration, symptoms of hypoxia can be subtle, making it difficult for individuals to recognize when they are affected.

Fortunately, the Tui Airways flight landed back in Manchester without any injuries reported, although the AAIB highlighted the significant risks the passengers and crew faced during the incident.