Aircraft Incidents Attributable to Human Factors
Aircraft Incidents Attributable to
Human Factors
On June 10th 1990, a British Airways BAC 1-11 suffered a catastrophic decompression in mid flight, resulting in Captain Tim Lancaster being partially sucked out of the aircraft. Only the quick reactions of flight attendant, Nigel Ogden, who managed to secure the captains legs and feet, meanwhile the co-pilot Alastair Atchison fought to descend the aircraft from 17,500ft to a safe altitude and eventually touch down safely on runway 02 at Southampton. After transportation to Southampton General Hospital, Captain Lancaster was found to be suffering from serious frostbite, fractures to his arm, wrist and left thumb. The following report will detail the causes of the accident and possible remedial action.
27 hours earlier, the aircraft G-BJRT, which Captain Lancaster was due to fly, was undergoing maintenance in which the windscreen was replaced. The windscreen of the 1-11 is not designed on the plug principle where the pressurised cabin pushes on the glass to help keep it in place. Instead, it is fitted on the outside of the aircraft with 90 countersunk bolts. During the replacement, the engineer also decided to replace the 90 countersunk bolts. On removal of the bolts, he failed to refer to the Illustrated Parts Catalogue (IPC) to get the right part number, instead he used eye judgement to attain the best matching bolts. 84 of the bolts used to replace the new windscreen were identified as part number A211-8C which were found to be about 0.026 of an inch below the ones specified in the IPC. The remaining 6 bolts were A211-7D which were the correct diameter but 0.1 of an inch to short. The old windscreen which was replaced 4 years earlier had therefore been primarily attached by relatively the same bolts.
Due to the incorrect sized bolts fitted, the windscreen was not properly secured in position. Consequently, as the aircrafts cabin pressurised to 8000ft, the window blew out due to the differential pressures
Human Factors
On June 10th 1990, a British Airways BAC 1-11 suffered a catastrophic decompression in mid flight, resulting in Captain Tim Lancaster being partially sucked out of the aircraft. Only the quick reactions of flight attendant, Nigel Ogden, who managed to secure the captains legs and feet, meanwhile the co-pilot Alastair Atchison fought to descend the aircraft from 17,500ft to a safe altitude and eventually touch down safely on runway 02 at Southampton. After transportation to Southampton General Hospital, Captain Lancaster was found to be suffering from serious frostbite, fractures to his arm, wrist and left thumb. The following report will detail the causes of the accident and possible remedial action.
27 hours earlier, the aircraft G-BJRT, which Captain Lancaster was due to fly, was undergoing maintenance in which the windscreen was replaced. The windscreen of the 1-11 is not designed on the plug principle where the pressurised cabin pushes on the glass to help keep it in place. Instead, it is fitted on the outside of the aircraft with 90 countersunk bolts. During the replacement, the engineer also decided to replace the 90 countersunk bolts. On removal of the bolts, he failed to refer to the Illustrated Parts Catalogue (IPC) to get the right part number, instead he used eye judgement to attain the best matching bolts. 84 of the bolts used to replace the new windscreen were identified as part number A211-8C which were found to be about 0.026 of an inch below the ones specified in the IPC. The remaining 6 bolts were A211-7D which were the correct diameter but 0.1 of an inch to short. The old windscreen which was replaced 4 years earlier had therefore been primarily attached by relatively the same bolts.
Due to the incorrect sized bolts fitted, the windscreen was not properly secured in position. Consequently, as the aircrafts cabin pressurised to 8000ft, the window blew out due to the differential pressures
Bibliography: http://www.aaib.gov.uk/cms_resources.cfm?file=/1-1992%20G-BJRT.pdf – as on 5th may 2011 http://en.wikipedia.org/wiki/British_Airways_Flight_5390 - as of 5th may 2011