AD NUMBER: 2020-03-17

PRODUCT: Certain Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes, Model CL600-2C10 (Regional Jet Series 700, 701, & 702) airplanes, Model CL-600-2D15 (Regional Jet Series 705) airplanes, Model CL-600-2D24 (Regional Jet Series 900) airplanes, and Model CL-600-2E25 (Regional Jet Series 1000) airplanes.

ACTION: Final rule

SUMMARY: The FAA superseding Airworthiness Directive (AD) 2015-24-04, which applied to certain Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes, Model CL600-2C10 (Regional Jet Series 700, 701, & 702) airplanes, Model CL-600-2D15 (Regional Jet Series 705) airplanes, Model CL-600-2D24 (Regional Jet Series 900) airplanes, and Model CL-600-2E25 (Regional Jet Series 1000) airplanes.

AD 2015-24-04 required repetitive inspections of the cage assembly for damaged or detached window louver panel assemblies (WLPAs) and blowout panels (BOPs), and corrective actions if necessary.

This AD requires one-time inspections of the WLPAs and BOPs, corrective actions if necessary, and a revision of the existing maintenance or inspection program, as applicable, to incorporate new airworthiness limitations, which would terminate the inspection requirement.

This AD was prompted by a determination that new airworthiness limitations, as well as additional actions, are necessary to address the unsafe condition.

DATES: This AD is effective April 2, 2020.

COST: The FAA estimates that this AD affects 1,008 airplanes of U.S. registry. Operators may incur the following costs in order to comply with this AD:

• Retained Inspections from AD 2015-24-04: 2 work-hours × $85 per hour = $170 per airplane.

The FAA has determined that revising the maintenance or inspection program takes an average of 90 work-hours per operator, although the agency 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).

The FAA has received no definitive data that would enable the agency to provide cost estimates for the on-condition actions specified in this AD.

FMI: AD