AD NUMBER: 2019-20-07

PRODUCT: All Boeing Model 787-8, 787-9, and 787-10 airplanes.

ACTION: Final rule; request for comments.

SUMMARY: This AD requires repetitive operational checks of the leading edge (LE) outboard (OB) slats and applicable on-condition actions.

This AD also requires revising the airplane flight manual (AFM) to prohibit flap retraction under icing conditions and revising the existing maintenance or inspection program, as applicable, to incorporate a new operation check.

This AD was prompted by a determination that the LE OB slat system could be out of position without flight deck annunciation.

DATES: This AD is effective October 11, 2019. The FAA must receive comments on this AD by November 25, 2019.

COST: The FAA estimates that this AD affects 118 airplanes of U.S. registry. Operators may incur the following costs in order to comply with this AD:

• Repetitive operational checks: Labor - 8 work-hours × $85 per hour = $680 per operational check per aircraft.
• AFM revision: 1 work-hour × $85 per hour = $85 per aircraft.
• (Does not include estimated costs for revising the existing maintenance or inspection program)

FMI: AD