Airworthiness Directive · Amendment 39-13724 · Bombardier Model DHC-8-400 Airplanes
Bombardier Model DHC-8-400 Airplanes
Model DHC-8-400 airplanes, serial numbers 4001 through 4055 inclusive; certificated in any category.
This amendment supersedes an existing airworthiness directive (AD), applicable to certain Bombardier Model DHC-8-400 airplanes. That AD currently requires revising the Normal and Abnormal sections of the airplane flight manual (AFM) to include procedures that enable the flightcrew to determine if the main landing gear (MLG) is extended before landing, and to take appropriate actions if necessary. This amendment adds an airplane to the applicability, and requires replacing the existing MLG downlock proximity sensors with new, improved sensors. After the replacement, this action also requires removing from the AFM the revision to the Normal and Abnormal sections required by the existing AD. The actions specified by this AD are intended to prevent failure of the MLG downlock proximity sensors on the same MLG at the same time, which could result in the MLG's failure to extend during landing, and cause injury to flightcrew and passengers. This action is intended to address the identified unsafe condition.
To prevent failure of the main landing gear (MLG) downlock proximity sensors on the same MLG at the same time, which could result in the MLG's failure to extend during landing, and cause injury to flightcrew and passengers, accomplish the following:
(a) Within 14 days after June 21, 2001 (the effective date of AD 2001-11-10, amendment 39-12253), revise the Normal and Abnormal sections of the airplane flight manual (AFM) by inserting the following into Section 4.21, opposite page 4.21.1. This may be accomplished by inserting a copy of this AD in the AFM.
If illumination of LEFT gear safe (green), and LEFT gear unsafe (red), and landing gear handle (amber) advisory lights with the landing gear handle in the up position.
Or
Illumination of RIGHT gear safe (green), and RIGHT gear unsafe (red), and landing gear handle (amber) advisory lights with the landing gear handle in the up position.
1. Perform an Alternate Landing Gear extension, See paragraph 4.21.
Selection of the gear down without following the Alternate Landing Gear Extension procedure may result in the affected gear being trapped inside the nacelle.
2. Visually inspect Main Landing Gear to confirm that it has been extended.
A down and locked indication of the affected main landing gear is not a valid indication of the gear position.
3. Insert hydraulic pump handle in socket and operate for a minimum of 12 full strokes and ensure resistance to pump handle movement.
4. Observe the LEFT gear safe (green) and RIGHT gear safe (green) advisory lights are illuminated and the LEFT gear unsafe (red) and RIGHT gear unsafe (red) and the landing handle (amber) advisory lights are extinguished.”
(b) Within 6 months after the effective date of this AD, replace the left-hand and right-hand MLG downlock proximity sensors with new, improved sensors having new part numbers, per the Accomplishment Instructions of Bombardier Service Bulletin 84-32-09, Revision A, dated November 20, 2001. Once the sensors have been replaced, the AFM revision required by paragraph (a) of this AD must be removed from the AFM.
Note 1: Bombardier Service Bulletin 84-32-09 references Menasco Aerospace Service Bulletin 46400-32-09, dated May 15, 2001, as an additional source of service information for accomplishment of the replacement. The Menasco service bulletin is included in the Bombardier service bulletin.
(c) Replacements accomplished before the effective date of this AD per Bombardier Service Bulletin 84-32-09, dated May 18, 2001, are considered acceptable for compliance with the corresponding action specified in this AD.
(d) In accordance with 14 CFR 39.19, the Manager, New York Aircraft Certification Office (ACO), FAA, is authorized to approve alternative methods of compliance (AMOCs) for this AD.
(e) Unless otherwise specified in this AD, the actions shall be done in accordance with Bombardier Service Bulletin 84-32-09, Revision A, dated November 20, 2001. 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-2001-16R1, dated June 3, 2002.
