Airworthiness Directives; Bombardier, Inc., Airplanes

The FAA proposes to supersede Airworthiness Directive (AD) 2020-19-13, which applies to certain Bombardier, Inc., Model CL-600- 1A11 (600), CL-600-2A12 (601), and CL-600-2B16 (601-3A, 601-3R, and 604 Variants) airplanes. AD 2020-19-13 requires a check to identify the manufacturer and part number of the portable oxygen bottle installation, and if necessary, modification of the portable oxygen bottle installation. Since the FAA issued AD 2020-19-13, it was determined that four additional airplanes are subject to the unsafe condition. This proposed AD would continue to require the actions specified in AD 2020-19-13 and would expand the applicability. The FAA is proposing this AD to address the unsafe condition on these products.