Case Study of Aloha Airlines
In order to know how to prevent and avoid such accidents from happening, we must first know what went wrong. As they say, the first step to resolving an issue to know and recognise that there is one.
After reading through various reports and investigations, I observed several points that contributed to the cause of the accident. Firstly, there were clear precursors that were not acted upon. Multiple Air Directives (AD) had directed inspections and repairs targeting specific sections of the airplane, but had not looked at the airplane as a whole. FAA AD 872121-08 mandated inspection of lap splices at fuselage stringer 4. This AD did not recognize the risk of failing to mandate inspections of all lap splices, and only mandated inspections of the known unsafe condition.
Boeing Alert Service Bulletin 737-53A1039 proposed inspection of all 737 lap joints ––Service Bulletin was NOT mandated as an AD.
Secondly, there was a lack of knowledge and experience in the area of corrosion detection and prevention. The maintenance crew from aloha that was carrying out maintenance for flight 243 had very little training and exposure in the area of corrosion resistance and detection. Therefore they were not experienced to carry out NDT on the lap joints or to detect in-depth corrosion.
Thirdly, there were flaws in the maintenance program of the Aloha airline and the airline industry in general. There was a high accumulation of flight cycles between structural inspections than previously forecasted by Boeing when the B-737 Maintenance Planning Document was released. Aloha airlines Boeing 737 aircraft flight 243 had 89,680 flight cycles and a 35,496 of flight hours which meant that there was frequent cabin pressurization due to the high number of short operating flights. This caused tremendous amounts of stress to the lap joint areas and led to the separation of the fuselage. Frequency of stress was not the only factor; the aircraft utilized a method of lap joining called
After reading through various reports and investigations, I observed several points that contributed to the cause of the accident. Firstly, there were clear precursors that were not acted upon. Multiple Air Directives (AD) had directed inspections and repairs targeting specific sections of the airplane, but had not looked at the airplane as a whole. FAA AD 872121-08 mandated inspection of lap splices at fuselage stringer 4. This AD did not recognize the risk of failing to mandate inspections of all lap splices, and only mandated inspections of the known unsafe condition.
Boeing Alert Service Bulletin 737-53A1039 proposed inspection of all 737 lap joints ––Service Bulletin was NOT mandated as an AD.
Secondly, there was a lack of knowledge and experience in the area of corrosion detection and prevention. The maintenance crew from aloha that was carrying out maintenance for flight 243 had very little training and exposure in the area of corrosion resistance and detection. Therefore they were not experienced to carry out NDT on the lap joints or to detect in-depth corrosion.
Thirdly, there were flaws in the maintenance program of the Aloha airline and the airline industry in general. There was a high accumulation of flight cycles between structural inspections than previously forecasted by Boeing when the B-737 Maintenance Planning Document was released. Aloha airlines Boeing 737 aircraft flight 243 had 89,680 flight cycles and a 35,496 of flight hours which meant that there was frequent cabin pressurization due to the high number of short operating flights. This caused tremendous amounts of stress to the lap joint areas and led to the separation of the fuselage. Frequency of stress was not the only factor; the aircraft utilized a method of lap joining called