AD 2020-12-13 Prompted By Reports That During Airplane Wing Fatigue Testing, Fatigue Cracks Were Found

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. This AD was prompted by reports that during airplane wing fatigue testing, fatigue cracks were found on the lower right-hand-side wing plank at the end of the integrally machined stringers, which led to a determination that new or more restrictive airworthiness limitations are necessary.

This AD requires, for certain airplanes, revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations. The FAA is issuing this AD to address the unsafe condition on these products.
This AD is effective September 10, 2020.

Supplementary Information: Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian AD CF-2019-21, dated May 15, 2019 (also referred to as the Mandatory Continuing Airworthiness Information, or “the MCAI”), to correct an unsafe condition for certain Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. You may examine the MCAI in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2019-0987.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain Bombardier, Inc., Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. The NPRM published in the Federal Register on December 27, 2019 (84 FR 71335). The NPRM was prompted by reports that during airplane wing fatigue testing, fatigue cracks were found on the lower right-hand-side wing plank at the end of the integrally machined stringers, which led to a determination that new or more restrictive airworthiness limitations are necessary. The NPRM proposed to require, for certain airplanes, revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations. The FAA is issuing this AD to address undetected cracks on the lower wing plank at the stringer run-out, which could affect the structural integrity of the wing. See the MCAI for additional background information.

FMI: www.regulations.gov