Date: 10th June 1990
Location: Near Didcot, UK
Aircraft: BAC 1-11-500, registration G-BJRT
Flight Number: BA5390
Operator: British Airways
Flight Route: Birmingham (UK) to Málaga (Spain)
Passengers: 81
Crew: 6
Summary of Events
On 10th June 1990, British Airways Flight 5390, a BAC 1-11-500 with 81 passengers and six crew on board, experienced a catastrophic windscreen failure at 17,000 feet. The incident resulted in rapid decompression of the cockpit, during which Captain Tim Lancaster was partially ejected from the aircraft. First Officer Alistair Atchison immediately assumed control of the aircraft and initiated an emergency descent. Despite the challenging conditions, he safely landed the plane at Southampton Airport approximately 22 minutes after the initial failure. No fatalities occurred, although Captain Lancaster sustained serious injuries.
Weather conditions at the time of the incident were clear, and the aircraft was in cruise when the windscreen failure occurred.
Aircraft and Crew Information
• Aircraft: The BAC 1-11-500 is a twin-engine short-haul jet with a pressurised fuselage, critical for maintaining cabin pressure at high altitudes.
• Crew:
• Captain Tim Lancaster: Over 11,000 flight hours.
• First Officer Alistair Atchison: Highly experienced with over 7,500 flight hours.
• Cabin crew, including Flight Attendant Nigel Ogden, assisted in the emergency response.
The aircraft was well within its operational limits, with its last maintenance check completed 27 hours before the flight.
Sequence of Events
• Pre-flight: Routine checks were carried out on the aircraft, including the replacement of the cockpit windscreen.
• In-flight: At an altitude of 17,000 feet, the newly installed windscreen failed, resulting in rapid decompression. The force of the decompression caused Captain Lancaster to be partially ejected from the cockpit, with his body pinned against the fuselage while his legs remained inside.
• Crew Response: First Officer Atchison immediately assumed manual control of the aircraft, disabling the autopilot. Simultaneously, Flight Attendant Nigel Ogden, with assistance from the other crew, managed to secure Captain Lancaster, preventing him from being fully ejected from the aircraft.
• Emergency Descent: Atchison initiated an emergency descent to 10,000 feet to mitigate the effects of decompression and prevent hypoxia among passengers and crew. Despite damaged communications, he successfully coordinated with air traffic control to divert the flight to Southampton Airport.
• Landing: The aircraft landed safely, approximately 22 minutes after the incident, with emergency services on standby to assist.
Investigation and Analysis
The Air Accidents Investigation Branch (AAIB) conducted a thorough investigation into the incident and determined that the windscreen failure was a result of human error during routine maintenance. The following findings were made:
1. Bolt Specification: The bolts securing the windscreen were undersized. They were 0.026 inches narrower and shorter than the manufacturer’s specifications. This incorrect size compromised the windscreen’s ability to withstand the high-pressure differential at altitude.
2. Human Error: The maintenance engineer responsible for the windscreen replacement did not follow proper procedures and relied on memory rather than consulting the maintenance manual. No torque checks were performed after the installation, allowing the error to go unnoticed until the failure occurred in flight.
3. Lack of Oversight: The investigation found insufficient oversight of the maintenance work. No cross-checks or supervisory reviews were conducted, which would have detected the improper installation before the aircraft was cleared for flight.
Conclusions
The root cause of the incident was the installation of incorrect bolts during routine maintenance. These bolts were unable to withstand the pressurisation loads at cruising altitude, leading to the catastrophic windscreen failure and subsequent decompression.
Contributing factors included:
• Human error in not following maintenance procedures.
• Lack of quality control and oversight, which failed to detect the improper installation.
The professionalism and quick responses of the crew, particularly First Officer Atchison and Flight Attendant Ogden, were pivotal in averting a potentially fatal outcome. Their actions ensured that all lives were saved.
Recommendations
In light of the findings, the following safety recommendations were made:
1. Maintenance Procedures: It was mandated that maintenance engineers must strictly adhere to the aircraft’s maintenance manual when replacing critical components. Verification procedures, such as torque testing and part cross-checks, were made compulsory for all critical repairs.
2. Human Factors Training: Aviation maintenance staff received enhanced human factors training to better understand the risks associated with procedural deviations and errors. This training aimed to reduce reliance on memory and reinforce the need to follow documented procedures.
3. Crew Resource Management (CRM): The importance of CRM was underscored by the crew’s ability to manage the crisis. CRM training became further integrated into both flight crew and ground personnel operations to improve communication and decision-making in emergencies.
4. Emergency Decompression Protocols: The procedures for handling rapid decompression were revised and strengthened, with additional crew training provided on the use of emergency oxygen systems and high-altitude emergencies.
Safety Lessons and Industry Impact
This incident highlighted the critical role of proper maintenance procedures and human factors in aviation safety. As a result, industry-wide changes were implemented to improve maintenance protocols, quality control, and emergency preparedness.
• Maintenance verification became a non-negotiable part of post-repair processes.
• CRM training was enhanced for all airline staff to ensure effective teamwork during crises.
• Decompression protocols were updated, including more frequent training and drills for handling in-flight emergencies.
The legacy of British Airways Flight 5390 serves as a reminder of the importance of vigilance, proper procedures, and teamwork in ensuring aviation safety.
