Airworthiness Directive · Amendment 39-14824 · BAE Systems (Operations) Limited Model BAe 146 and Avro 146-RJ Airplanes
BAE Systems (Operations) Limited Model BAe 146 and Avro 146-RJ Airplanes
This AD applies to all BAE Systems (Operations) Limited Model BAe 146-100A, -200A, and -300A series airplanes; and Model Avro 146-RJ70A, 146-RJ85A, and 146-RJ100A airplanes; certificated in any category; equipped with hydraulic accumulators part number (P/N) AIR91666-0, -1, or -2 installed.
The FAA is adopting a new airworthiness directive (AD) for all BAE Systems (Operations) Limited Model BAe 146 and Avro 146-RJ airplanes equipped with certain hydraulic accumulators. This AD requires inspecting the hydraulic accumulators to identify certain serial numbers, and replacing any affected accumulator with a new or serviceable accumulator. Operators may delay doing the replacement by doing repetitive inspections of the affected hydraulic accumulators for signs of failure (leaking or cracking), and replacing any failed accumulator with a new or serviceable unit. This AD results from a report that one hydraulic accumulator failed in service, which caused the loss of the yellow hydraulic system when the airplane was configured for landing. We are issuing this AD to prevent damage to the pressure skin, failure of certain hydraulic systems, contamination of the cabin with hydraulic mist, increased workload for the flightcrew associated with the loss of one or more hydraulic circuits, and consequent reduced controllability of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 48 hours after the effective date of this AD, inspect all P/N AIR91666-0, -1, and -2 hydraulic accumulators to determine whether any hydraulic accumulator is installed that has an S/N identified in paragraph C of the Accomplishment Instructions of BAE Systems (Operations) Limited Inspection Service Bulletin ISB.29-A046, dated March 14, 2006. A review of airplane maintenance records is acceptable in lieu of this inspection if the S/N can be conclusively determined from that review.
If any accumulator with an affected S/N is identified during the inspection required by paragraph (f) of this AD, do the action in paragraph (g)(1) or (g)(2) of this AD. Do all actions in accordance with the Accomplishment Instructions of BAE Systems (Operations) Limited Inspection Service Bulletin ISB.29-A046, dated March 14, 2006, except where the service bulletin specifies to submit certain information to the manufacturer, this AD does not include that requirement.
(1) Before further flight: Replace the hydraulic accumulator with a new or serviceable accumulator.
(2) Before further flight: Do a detailed inspection for signs of failure (leaking or cracking) of the hydraulic accumulator, and replace any failed accumulator before further flight. If there is no sign of failure, repeat the inspection thereafter at the applicable interval in paragraph (g)(2)(i) or (g)(2)(ii) of this AD. Within 75 days after the effective date of this AD, replace the affected hydraulic accumulator with a new or serviceable accumulator. Doing the replacement terminates the repetitive inspections.
(i) At intervals not to exceed 48 hours.
(ii) Before further flight following a report of hydraulic fumes in the cabin air supply, or after a hydraulic fluid low-level warning; and thereafter at intervals not to exceed 48 hours.
(h) For airplanes on which more than one affected accumulator is identified during the inspection required by paragraph (f) of this AD: Within 12 days after the effective date of this AD, replace any affected accumulator in accordance with paragraph (g)(1) of this AD, so that no more than one accumulator with an affected S/N remains on the airplane; and inspect any remaining accumulator at the applicable interval in paragraph (g)(2) of this AD.
Note 1: BAE Systems (Operations) Limited Service Bulletin ISB.29-A046, dated March 14, 2006, refers to APPH Service Bulletin AIR91666-29-02, dated March 2006, as an additional source of service information for determining if an accumulator is a serviceable accumulator. The procedures include disassembling the accumulator cylinder, and testing it for cracking.
Note 2: For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”
(i) Except as provided by paragraph (g)(2) of this AD: As of the effective date of this AD, no hydraulic accumulator having P/N AIR91666-0, -1, or -2 that has an S/N identified in paragraph C. of the Accomplishment Instructions of BAE Systems (Operations) Limited Inspection Service Bulletin ISB.29-A046, dated March 14, 2006, may be installed on any airplane except for accumulators on which the actions specified in the Accomplishment Instructions of APPH Service Bulletin AIR91666-29-02, dated March 2006, have been done.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
