While waiting in a doctor's office I picked up a recent copy of Newsweek. In it was a quite extensive report on the problem of 737 fuselages opening up. Here are a few points I had not heard before.
1. The 737 fuselage was adapted from the 727, a 1960s design. This greatly reduced the time and effort for design and certification.
2. The skin is unusually thin. This was due to a need for light weight, which was due to the relatively low power engines available back then.
3. The failure mode of the fuselage "unziping" at seams was anticipated. However, this failure mode is happening at less than 1/2 the expected number of flight cycles. The analysis is suspect.
4. Frequent inspections may prevent future failures in flight. However, many 727s are operated in underdeveloped parts of the world, where the eagle eye of the FAA is absent.
I don't generally hold Newsweek in high regard but this particular report seemed OK.
1. The 737 fuselage was adapted from the 727, a 1960s design. This greatly reduced the time and effort for design and certification.
2. The skin is unusually thin. This was due to a need for light weight, which was due to the relatively low power engines available back then.
3. The failure mode of the fuselage "unziping" at seams was anticipated. However, this failure mode is happening at less than 1/2 the expected number of flight cycles. The analysis is suspect.
4. Frequent inspections may prevent future failures in flight. However, many 727s are operated in underdeveloped parts of the world, where the eagle eye of the FAA is absent.
I don't generally hold Newsweek in high regard but this particular report seemed OK.
