AD 2020-12-15 Requires A Measurement Of The Trunnion Nut Torque Of The V-Band Clamp

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier, Inc., Model BD-700-1A10 and BD-700-1A11 airplanes.

This AD was prompted by a report that certain safety valves at the left- and right-hand sides of the cabin pressure control system were not installed correctly and that the trunnion nuts used to fasten the V-band clamp were over torqued. This AD requires a measurement of the trunnion nut torque of the V-band clamp, an inspection of the safety valve and airplane bulkhead flange area for any cracking and deformations, and corrective actions, if necessary. The FAA is issuing this AD to address the unsafe condition on these products. This AD becomes effective July 24, 2020.

Supplementary Information: Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian AD CF-2020-16, dated May 15, 2020 (referred to after this as the Mandatory Continuing Airworthiness Information, or “the MCAI”), to correct an unsafe condition for certain Bombardier, Inc., Model BD-700-1A10 and BD-700-1A11 airplanes. You may examine the MCAI on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0575.

This AD was prompted by a report that certain safety valves at the left- and right-hand sides of the cabin pressure control system were not installed correctly and that the trunnion nuts used to fasten the V-band clamp were over torqued. The FAA is issuing this AD to address incorrect installation of the safety valves and over-torqued trunnion nuts, which could cause damage to the safety valve flange and could result in pressure leakage or cabin depressurization at altitude. See the MCAI for additional background information.

FMI: www.regulations.gov