Airworthiness Directive · Amendment 39-13691 · Bombardier Model DHC-8-301, -311, and -315 Airplanes
Bombardier Model DHC-8-301, -311, and -315 Airplanes
Model DHC-8-301, -311, and -315 airplanes, serial numbers 100 through 583, inclusive; certificated in any category.
This amendment adopts a new airworthiness directive (AD), applicable to certain Bombardier Model DHC-8-301, -311, and -315 airplanes. This AD requires determining the modification number of the angle of attack (AOA) sensor vanes; testing the movement of the affected vanes to evaluate sticking against both the upper and the lower vane travel end stops; and corrective action, if necessary. This action is necessary to prevent an incorrect AOA indication to the stall warning system in flight, which could result in an inadvertent stall and consequent loss of control of the airplane. This action is intended to address the identified unsafe condition.
To prevent an incorrect angle of attack (AOA) indication to the stall warning system in flight, which could result in an inadvertent stall and consequent loss of control of the airplane, accomplish the following:
(a) The term “service bulletin,” as used in this AD, means the Accomplishment Instructions of Bombardier Alert Service Bulletin A8-27-94, Revision ‘A’, dated February 5, 2002.
Note 1: Bombardier Alert Service Bulletin A8-27-94, Revision ‘A’, references Rosemount Aerospace Alert Service Bulletin 0861CAB-27A-07, dated September 28, 2001, as an additional source of service information for testing the AOA sensors. The Rosemount service bulletin is included in the Bombardier service bulletin.
(b) Within 1,000 flight hours or 18 months after the effective date of this AD, whichever occurs first, inspect the right and left AOA sensor vanes to determine whether modification (MOD) ‘J’ has been incorporated. Instead of inspecting the sensors, a review of airplane maintenance records is acceptable if the MOD level of the sensor can be positively determined from that review. If MOD ‘J’ has been incorporated in both sensors, no further action is required by this paragraph.
(c) For any AOA sensor vane that does not have MOD ‘J’ installed: Prior to further flight following the inspection required by paragraph (b) of this AD, do a movement test of the AOA sensor vane per the service bulletin.
(d) If the result of the movement test in paragraph (c) of this AD is less than 110 grams, repeat the movement test prior to the accumulation of 5,000 flight hours or 24 months after accomplishing the initial test, whichever occurs first. Do the test per the service bulletin.
(e) If the result of any movement test in paragraph (c) or paragraph (d) of this AD is 110 grams or more, replace the AOA sensor vane with a reworked MOD ‘J’ sensor vane, per the service bulletin, at the applicable time in paragraph (e)(1), (e)(2), or (e)(3) of this AD.
(1) If the result of the movement test in paragraph (c) of this AD is between 110 and 169 grams inclusive, replace the sensor vane at the earlier of 1,000 flight hours, or 18 months after accomplishing the movement test in paragraph (c) of this AD.
(2) If the result of any repeat movement test in paragraph (d) of this AD is between 110 and 169 grams inclusive, replace the sensor vane at the earlier of 1,000 flight hours or 6 months after accomplishing the movement test in paragraph (d) of this AD.
(3) If the result of the movement test is 170 grams or more, replace the sensor vane within 5 days after the accomplishing the movement test in paragraph (c) or paragraph (d) of this AD.
(f) As of the effective date of this AD, no person may install a sensor vane, part number 861CAB, on any airplane unless MOD “J” has been incorporated.
(g) Although the Rosemount service bulletin contains procedures for sending test findings to the manufacturer, and for sending removed parts to the manufacturer for modification, this AD does not require those actions.
(h) Actions accomplished before the effective date of this AD per Bombardier Alert Service Bulletin A8-27-94, dated October 25, 2001, are considered acceptable for compliance with the corresponding action specified in this AD.
(i) In accordance with 14 CFR 39.19, the Manager, New York Aircraft Certification Office, FAA, is authorized to approve alternative methods of compliance for this AD.
(j) Unless otherwise specified in this AD, the actions shall be done in accordance with Bombardier Alert Service Bulletin A8-27-94, Revision “A”, dated February 5, 2002. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, suite 410, Westbury, New York; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
Note 2: The subject of this AD is addressed in Canadian airworthiness directive CF-2001-46, dated December 3, 2001.
