AD NUMBER: 2019-08-04

PRODUCT: Certain Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes.

ACTION: Final Rule.

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2012-25-02, which applied to the product listed above.

AD 2012- 25-02 required revising the airworthiness limitations section (AWL) of the instructions for continued airworthiness (ICA) of the maintenance requirements manual (MRM) by incorporating new procedures for repetitive inspections for cracking of the rear pressure bulkhead (RPB).

AD 2012-25- 02 also required revising the maintenance or inspection program to incorporate a revised task. This AD also mandates modification of the RPB and adds repetitive inspections for cracking of the RPB web, which terminates certain actions in this AD.

This AD was prompted by additional in-service crack findings, which resulted in the development of a structural modification to the RPB.

DATES: This AD is effective July 12, 2019.

COST: The FAA estimates that this AD affects 457 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 maintenance or inspection program takes an average of 90 work-hours per operator, although 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), a per-operator estimate is more accurate than a per-airplane estimate. Therefore, the estimated total cost per operator is $7,650 (90 work-hours x $85 per work-hour).

The FAA has received no definitive data that would enable us to provide cost estimates for the oncondition actions specified in this AD.

FMI: AD