AD 95-04-09

This amendment adopts a new airworthiness directive (AD) that applies to Pilatus Britten-Norman BN2A, BN2B, and BN2T Islander and BN2A Mk III Trislander series airplanes that are equipped with a nose wheel steering disconnect system with either a Modification NB/M/503 or Modification NB/M/733 nose undercarriage unit. This action requires repetitively inspecting the nose wheel steering drive ring for cracks, and replacing any cracked drive ring. A report of the rudder pedals jamming in the central position during takeoff on one of the affected airplanes prompted this action. The actions specified by this AD are intended to prevent failure of the nose wheel steering system because of a cracked drive ring, which, if not detected and corrected, could result in the inability to move the rudder pedals.

Final rule.

95-04-09 PILATUS BRITTEN-NORMAN: Amendment 39-9161; Docket No. 94-CE-10-AD.

Applicability: BN2A, BN2B, and BN2T Islander and BN2A Mk III Trislander series airplanes, certificated in any category, that are equipped with a nose wheel steering disconnect system with either a Modification NB/M/503 or Modification NB/M/733 nose undercarriage unit.

Compliance: Required within the next 100 hours time-in-service (TIS), unless already accomplished, and thereafter at intervals not to exceed 100 hours TIS.

To prevent failure of the nose wheel steering system because of a cracked drive ring, which, if not detected and corrected, could result in the inability to move the rudder pedals, accomplish the following:

(a) Visually inspect the nose wheel steering drive ring for cracks in accordance with the ACTION section of Pilatus Britten-Norman Service Bulletin No. BN-2/SB.214, Issue 1, dated September 23, 1993. Prior to further flight, replace any cracked nose wheel steeringdrive ring in accordance with the applicable maintenance manual.

(b) 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 requirements of this AD can be accomplished.

(c) An alternative method of compliance or adjustment of the initial or repetitive compliance time that provides an equivalent level of safety may be approved by the Manager, Brussels Aircraft Certification Office (ACO), FAA, Europe, Africa, and Middle East Office, c/o American Embassy, B-1000 Brussels, Belgium. The request should be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Brussels ACO.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Brussels ACO.

(d) The inspection required by this AD shall be done inaccordance with Pilatus Britten-Norman Service Bulletin No. BN-2/SB.214, Issue 1, dated September 23, 1993. 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 Pilatus Britten-Norman Ltd, Bembridge, Isle of Wight, United Kingdom, PO35 5PR. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief 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.

(e) This amendment becomes effective on April 14, 1995.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Pilatus Britten-Norman BN2A, BN2B, and BN2T Islander and BN2A Mk III Trislander series airplanes that are equipped with a nose wheel steering disconnect system with either a Modification NB/M/503 or Modification NB/M/733 nose undercarriage unit was published in the Federal Register on October 25, 1994 (59 FR 53615). The action proposed to require repetitively inspecting the nose wheel steering drive ring for cracks, and replacing any cracked drive ring. The proposed inspection would be accomplished in accordance with Pilatus Britten-Norman Service Bulletin No. BN-2/SB.214, Issue 1, dated September 23, 1993. The drive ring replacement, if necessary, would be accomplished in accordance with the applicable maintenance manual.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposed rule or the FAA's determination of the cost to the public.

After careful review of all available information, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD or add any additional burden upon the public than was already proposed.

The FAA estimates that 15 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 1 workhour per airplane to accomplish the required action, and that the average labor rate is approximately $60 an hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $900. This figure does not take into account the cost of repetitive inspections or the cost of replacing any cracked drive ring. The FAA has no way of determining how many repetitive inspections each owner/operator would incur over the life of the airplane or how many drive rings may be cracked.

The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the final evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption "ADDRESSES".

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

Section 39.13 - [AMENDED]
2. Section 39.13 is amended by adding a new AD to read as follows: