KLM Royal Dutch Airlines - Fleet Services

With regard to the NPRM 2007-NM-160-AD, KLM has the following two (2) comments: 1. Par. (h) of the NPRM states the following: Quote "As of the effective date of this AD, no person may install a part identified in Table 1 of this AD on any airplane." unquote. The table lists certain p/n?s hinge braces for track 1, 2, 7 and 8 and it lists the old type support assemblies of transmissions 1, 2, 7 and 8. Effectively this means that if an old type transmission has to be replaced unscheduled after the effective date of the AD (because it starts leaking for example), the operator may no longer install a replacement transmission of the old type. Therefore, the operator is forced to modify the airplane at a most inconvenient moment, when manpower and spare parts may not be available. This could lead to a very long AOG situation. It is anticipated that the down time may last up to a week. This has an enormous potential impact on fleet operational performance. Therefore, KLM ask the FAA either to delete this statement or alter it to: "As of the effective date of this AD, no person may install a part identified in Table 1 of this AD having accumulated more than 20,000 flight cycles or whose number of flight cycles is unknown". 2. Furthermore, the impact of the modification is such that it has to be performed during a D-check. At this moment the first D-check of a B747-400 stands at 8 years, the second at 6 years. Boeing is investigating the possibility of extending the second D-check to even 8 years. That could mean that several aircraft need a special modification program, resulting in extra down time, much more than the suggested 15 hours by Boeing. Therefore, KLM would like the Compliance Time be set at 8 years for transmission assemblies having accumulated less that 20.000 flight cycles. Best regards, Arjan Meijer Director Quality Assurance & Project Management Fleet Services KLM Royal Dutch Airlines