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97-22-01 PILATUS BRITTEN-NORMAN: Amendment 39-10170; Docket No. 96-CE-25-AD.
Applicability: Models BN-2, BN-2A, BN-2A-2, BN-2A-3, BN-2A-6, BN-2A-8, BN-2A-9, BN-2A-20, BN-2A-21, BN-2A-26, BN-2A-27, BN-2B-20, BN-2B-21, BN-2B-26, BN-2B-27, and BN-2T airplanes (all serial numbers), certificated in any category.
NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (f) of this AD. The request should include an assessment of the effect of the replacement, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the requestshould include specific proposed actions to address it.
Compliance: Required as indicated after the effective date of this AD, unless already accomplished.
To prevent failure of the main landing gear caused by cracks in the torque link assembly area, which could lead to loss of control of the airplane during landing operations, accomplish the following:
(a) Prior to further flight after the effective date of this AD or within the next 100 hours time-in-service (TIS) after the last inspection required by AD 86-07-02, whichever occurs later, and thereafter at intervals not to exceed 100 hours TIS until the installations required by paragraph (c) of this AD are accomplished, inspect the junction of the torque link lug and upper case of all main landing gear (MLG) torque link assemblies for cracks (using a 10-power magnifying glass or by dye penetrant methods). Accomplish these inspections in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of Fairey Hydraulics Limited Service Bulletin (SB) 32-4, Issue 4, dated January 30, 1990. Pilatus Britten-Norman SB BN-2/SB.170, Issue 4, November 16, 1990, references this service bulletin.
NOTE 2: The inspections required by paragraph (a) of this AD were initially a part of AD 86-07-02, which applied to the BN2A MK. 111 series airplanes as well as the airplanes affected by this AD. The "prior to further flight after the effective date of this AD" compliance time was the original initial compliance time of AD 86-07-02, and is being retained to provide credit and continuity for already-accomplished and future inspections.
(b) If any cracks are found during any of the inspections required by this AD, prior to further flight, replace the MLG torque link assembly with a Modification A39 MLG torque link assembly in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of Fairey Hydraulics Limited SB No. 32-4, Issue 4, dated January 30, 1990.
(1) Repetitive inspections are no longer required when all MLG torque assemblies are replaced with Modification A39 MLG torque link assemblies.
(2) Repetitive inspections may no longer be required on one MLG torque assembly, but still be required on another if all haven't been replaced with a Modification A39 MLG torque link assembly.
(c) Upon the accumulation of 5,000 hours TIS or within the next 1,000 hours TIS after the effective date of this AD, whichever occurs later, unless already accomplished as specified in paragraph (b) of this AD, replace each MLG torque link assembly with a Modification A39 MLG torque link assembly in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of Fairey Hydraulics Limited SB No. 32-4, Issue 4, dated January 30, 1990.
(d) The intervals between the repetitive inspections required by this AD may be adjusted up to 10 percent of the specified interval to allow accomplishing these actions along with other scheduled maintenance on the airplane.
(e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the inspection requirements of this AD can be accomplished.
(f) An alternative method of compliance or adjustment of the initial or repetitive compliance times that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City, Missouri 64106. The request should be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate.
NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate.
(g) The inspections and replacement required by this AD shall be done in accordance with Fairey Hydraulics Limited Service Bulletin (SB) 32-4, Issue 4, dated January 30, 1990. 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 Fairey Hydraulics Limited, Claverham, Bristol, England; or Pilatus Britten-Norman Limited, Bembridge, Isle of Wight, United Kingdom PO35 5PR. Copies may be inspected at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(h) This amendment (39-10170) becomes effective on November 28, 1997.
