AD NUMBER: 2019-18-03

PRODUCT: Boeing Model 737 series airplanes, excluding Model 737-100, -200, -200C, -300, -400, and -500 series airplanes.

ACTION: Final rule; request for comments.

SUMMARY: This AD requires revising the existing maintenance or inspection program to remove text that allows the size of the thrust reverser upper locking actuator lock sensor target to be changed, and, for certain airplanes, performing repetitive integrity tests of the thrust reverser upper locking actuator.

This AD was prompted by a report indicating that alteration of thrust reverser upper locking actuators in accordance with certain data in the Boeing aircraft maintenance manual (AMM) could delay or prevent detection of the failure of the locking mechanism of a thrust reverser upper locking actuator.

DATES: This AD is effective October 3, 2019. Comments must be received by November 4, 2019.

COST: The FAA estimates that this AD affects 2,149 airplanes of U.S. registry. Operators may incur the following costs in order to comply with this AD:

Integrity test (2,039 airplanes):

• Labor: 8 work-hours × $85 per hour = $680 per test cycle per airplane.

Actuator replacement (if required)

• Labor: 8 work-hours × $85 per hour = $680.
• Parts: $38,908.
• Cost per Airplane: $39,588.

According to the manufacturer, some or all of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected individuals.

FMI: AD