Since September last year when fuselage fatigue cracks caused by an incorrect maintenance procedure came to light on some Ryanair Boeing 737-200s and Qantas 747-400s, Boeing has found the same type of damage in 53 aircraft, the US Federal Aviation Administration reveals. The Australian Civil Aviation Safety Authority (CASA) has warned that the FAA, which has already added its advice to Boeing bulletins on the subject, may produce an airworthiness directive making aircraft inspections and repairs mandatory.
Two Qantas 747-400s were grounded temporarily in September after serious cracks, originating from damage caused by workers using metal instead of wood implements to scrape old sealant and paint out of lap joints during repainting, were found in the fuselages during D checks. The aircraft were acquired from Malaysia Airlines in 1998. At about the same time Ryanair claimed that it had to retire its six 737-200s early because of "scribing" damage, which is the term given to the marks made in the metal by scraping (Flight International, 10-16 February). Boeing has revealed that scribing can lead to cracks 130-250mm (5-10in) long, 22,000 cycles after the damage was caused.
Boeing says that now 32 737s, four 747s and seven 757s have been found with scribing-related cracking, and it is working with the FAA to determine whether more inspection and repair solutions are required, according to CASA.
EMMA KELLY / PERTH & DAVID LEARMOUNT / LONDON
Source: Flight International
