AD 95-19-11

This amendment adopts a new airworthiness directive (AD), applicable to all British Aerospace Model Viscount 744, 745D, and 810 airplanes, that requires inspections to detect cracking of certain fittings of the tailplane spar, and replacement of the fittings with serviceable parts, if necessary. This amendment is prompted by reports of fatigue cracking of certain fittings in the tailplane spar. The actions specified by this AD are intended to prevent such cracking, which could result in structural degradation of the attachment of the horizontal stabilizer to the fuselage.

Final rule

95-19-11 BRITISH AEROSPACE REGIONAL AIRCRAFT LIMITED (Formerly British Aerospace Commercial Aircraft Limited, Vickers-Armstrongs Aircraft Limited): Amendment 39-9373. Docket 94-NM-111-AD.
Applicability: All Model Viscount 744, 745D, and 810 airplanes, 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 use the authority provided in paragraph (d) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effectof the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent structural degradation of the attachment of the horizontal stabilizer to the fuselage, accomplish the following:

(a) For Model Viscount 744 and 745D airplanes: Within 3,000 landings or 3 years after the effective date of this AD, whichever occurs first, perform a high frequency eddy current (HFEC) inspection to detect cracking of the bolt holes on the top fittings of the root joint of the tailplane spar, in accordance with British Aerospace Alert Preliminary Technical Leaflet (PTL) 264, Issue 3, dated September 1, 1992. Repeat the inspection thereafter at intervals not to exceed 3,000 landings or 3 years, whichever occurs first.

(b) For Model Viscount 810 airplanes: Within 1,000 landings or 1 year after the effective date of this AD, whichever occurs first, perform an HFEC inspection to detect cracking of the bolt holes on the top fittings of the root joint of the tailplane spar, in accordance with British Aerospace Alert PTL 127, Issue 3, dated June 1, 1992. Repeat the inspection thereafter at intervals not to exceed 3,000 landings or 3 years, whichever occurs first.

(c) If any cracking is found during the inspections required by paragraph (a) or (b) of this AD, prior to further flight, replace the cracked fitting with a serviceable part, in accordance with British Aerospace Alert PTL 264, Issue 3, dated September 1, 1992 (for Model 744 and 745D airplanes), or Alert PTL 127, Issue 3, dated June 1, 1992 (for Model 810 airplanes); as applicable.

(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Standardization Branch, ANM-113.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(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 requirements of this AD can be accomplished.

(f) The inspection and replacement shall be done in accordance with British Aerospace Alert Preliminary Technical Leaflet (PTL) 264, Issue 3, dated September 1, 1992; or British Aerospace Alert PTL 127, Issue 3, dated June 1, 1992; as applicable. 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 British Aerospace Regional Aircraft Ltd., Engineering Support Manager, Military Business Unit, Chadderton Works, Greengate, Middleton, Manchester M24 1SA, England. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on October 20, 1995.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to all British Aerospace Model Viscount 744, 745D, and 810 airplanes was published in the Federal Register on May 1, 1995 (60 FR 21056). That action proposed to require repetitive high frequency eddy current inspections to detect cracking of certain fittings of the tailplane spar, and replacement of the fittings with serviceable parts, if necessary.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

The FAA estimates that 29 airplanes of U.S. registry will be affected by this AD, that it will take approximately 4 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $6,960, or $240 per airplane.

The total cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

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 "significantregulatory 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 final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from 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: 49USC 106(g), 40101, 40113, 44701.

39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: