AD NUMBER: 2019-23-14

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

ACTION: Final rule

SUMMARY: This AD was prompted by significant changes made to the airworthiness limitations (AWLs) related to fuel tank ignition prevention and the nitrogen generation system.

This AD requires revising the existing maintenance or inspection program, as applicable, to include new or revised AWLs.

DATES: This AD is effective January 21, 2020

COST: The FAA estimates that this AD affects 381 airplanes of U.S. registry. Operators may incur the following costs in order to comply with this AD:

The FAA has determined that revising the existing maintenance or inspection program takes an average of 90 work-hours per operator, although the FAA recognizes that this number may vary from operator to operator.

In the past, the FAA has estimated that this action takes 1 work-hour per airplane. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), the FAA has determined that a per-operator estimate is more accurate than a per-airplane estimate.

Therefore, the FAA estimates the total cost per operator to be $7,650 (90 work-hours x $85 per work-hour).

FMI: AD