AD NUMBER: 2018-16-06

PRODUCT: Certain The Boeing Company Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, 747SP, and 747SR, and 747-8 series airplanes.

ACTION: Final Rule.

SUMMARY: This AD was prompted by reports indicating that additional areas of Boeing Material Specification (BMS) 8-39 flexible urethane foam were found during an inspection required by a related AD.

This AD requires inspecting for BMS 8-39 flexible urethane foam insulation in the floor panel assemblies and the power drive unit (PDU) cover assemblies, doing applicable on-condition actions, modifying certain dripshields, and replacing BMS 8-39 foam strips on certain dripshields with BMS 8-371 foam strips.

DATES: This AD is effective September 12, 2018.

COST: The FAA estimates that this AD affects 87 airplanes of U.S. registry. The cost of compliance is estimated as follows:

• Inspection and replacement.- Labor - 25 work-hour ×$85 per hour = $2,125; Parts - Up to $184,460; Cost per aircraft - Up to $186,585.
• Modification and installation of the dripshields. Labor- 10 work-hours × $85 per hour = $850; Cost per aircraft - $850.
• Replacement of the foam on the dripshields. Labor - 8 work-hours × $85 per hour = $680; Cost per aircraft - $680.

FMI: AD