Airworthiness Directive · Amendment 39-19924 · Pneumatic
Bombardier, Inc., Airplanes
This AD applies to Bombardier, Inc., Model BD-700-1A10 and BD-700-1A11 airplanes, certificated in any category, serial numbers 9810 through 9838 inclusive, 9840 through 9842 inclusive, 9844 through 9846 inclusive, 9854 and 9855.
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.
Before August 31, 2020, measure the trunnion nut torque of the V-band clamps at the left-and right-hand sides of the cabin pressure control system safety valves, in accordance with paragraphs 2.B.(1) and 2.B.(2) of the Accomplishment Instructions of the applicable service information specified in figure 1 to paragraphs (g) and (h) of this AD.
Based on the torque measurement required by paragraph (g) of this AD, do the applicable actions specified in paragraph (h)(1) or (2) of this AD.
(1) For safety valves with a V-band clamp trunnion nut torque of less than 80 lbf-in: Before further flight, do a general visual inspection for any cracking and deformation, in accordance with paragraph 2.B.(3)(a) of the Accomplishment Instructions of the applicable service information specified in figure 1 to paragraphs (g) and (h) of this AD.
(i) If no cracking and deformation is found on the safety valve and airplane bulkhead flange: Before further flight, re-torque the V-band clamp trunnion nut, in accordance with paragraph 2.B.(3)(b) of the Accomplishment Instructions of the applicable service information specified in figure 1 to paragraphs (g) and (h) of this AD.
(ii) If any cracking or deformation is found on the safety valve: Before further flight, replace the safety valve, in accordance with paragraph 2.C. of the Accomplishment Instructions of the applicable service information specified in figure 1 to paragraphs (g) and (h) of this AD.
(iii) If any cracking or deformation is found on the airplane bulkhead flange: Before further flight, repair using a method approved by the Manager, New York ACO Branch, FAA; or Transport Canada Civil Aviation (TCCA); or Bombardier, Inc.'s TCCA Design Approval Organization (DAO). If approved by the DAO, the approval must include the DAO-authorized signature.
(2) For safety valves with a V-band clamp trunnion nut torque of 80 lbf-in or higher: Before further flight, do a magnification inspection for any cracking and deformation of the safety valve and airplane bulkhead flange area, in accordance with paragraphs 2.B.(4)(a) and 2.B.(4)(b) of the Accomplishment Instructions of the applicable service information specified in figure 1 to paragraphs (g) and (h) of this AD.
(i) If no cracking and deformation is found on the safety valve and airplane bulkhead flange, do the actions specified in paragraphs (h)(2)(i)(A) and (B) of this AD.
(A) Before further flight, re-install the safety valve and torque the V-band clamp trunnion nut, in accordance with paragraph 2.B.(4)(c) of the Accomplishment Instructions of the applicable service information specified in figure 1 to paragraphs (g) and (h) of this AD.
(B) Before August 31, 2021, replace the safety valve, in accordance with paragraph 2.C. of the Accomplishment Instructions of the applicable service information specified in figure 1 to paragraphs (g) and (h) of this AD.
(ii) If any cracking or deformation is found on the safety valve: Before further flight, replace the safety valve, in accordance with paragraph 2.C. of the Accomplishment Instructions of the applicable service information specified in figure 1 to paragraphs (g) and (h) of this AD.
(iii) If any cracking or deformation is found on the airplane bulkhead flange: Before further flight, repair using a method approved by the Manager, New York ACO Branch, FAA; or TCCA; or Bombardier, Inc.'s TCCA DAO. If approved by the DAO, the approval must include the DAO-authorized signature.
