AD 98-12-21

This amendment adopts a new airworthiness directive (AD), applicable to Eurocopter France Model SA. 315B helicopters that requires an initial and repetitive visual inspections and modification, if necessary, of the horizontal stabilizer spar tube (spar tube). This amendment is prompted by an in-service report of fatigue cracks that initiated from corrosion pits. The actions specified by this AD are intended to prevent fatigue failure of the spar tube, separation and impact of the horizontal stabilizer with the main or tail rotor and subsequent loss of control of the helicopter.

Final rule

98-12-21 EUROCOPTER FRANCE: Amendment 39-10575. Docket No. 98-SW-02-AD.
Applicability: Model SA. 315B helicopters with horizontal stabilizers, part number (P/N) 315A35-10-000-1, 315A35-10-000-2, or higher dash numbers, installed, certificated in any category.

NOTE 1: This AD applies to each helicopter 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 helicopters 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 (e) 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 effect of the changed configurationon the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent a fatigue failure of the horizontal stabilizer spar tube (spar tube), impact of the horizontal stabilizer with the main or tail rotor and subsequent loss of control of the helicopter, accomplish the following:

(a) Before further flight:
(1) Inspect the aircraft records and the horizontal stabilizer installation to determine whether Modification 072214 (installation of the spar tube without play) or Modification 072215 (adding two half-shells on the spar) has been accomplished.

(2) If Modification 072214 has not been installed, comply with paragraphs 2.A., 2.B.1), 2.B.2)a), and 2.B.2)b) of the Accomplishment Instructions of Eurocopter France Service Bulletin No. 55.01, Revision 3, dated April 25, 1997 (servicebulletin). If the fit and dimensions of the components specified in paragraph 2.B.2)a) exceed the tolerances in the applicable structural repair manual, replace with airworthy parts.

(3) If Modification 072215 has not been installed, first comply with paragraphs 2.A., 2.B.1), and 2.B.3), and then comply with paragraph 2.B.2)c) of the Accomplishment Instructions of the service bulletin.

NOTE 2: Modification kit P/N 315A-07-0221571 contains the necessary materials to accomplish this modification.

(b) Before the first flight of each day:
(1) Visually inspect the installation of the half-shells, the horizontal stabilizer supports, and the horizontal stabilizer for corrosion or cracks. Repair any corroded parts in accordance with the applicable maintenance manual. Replace any cracked components with airworthy parts before further flight.

(2) Confirm that there is no play in the horizontal stabilizer supports by lightly shaking the horizontal stabilizer. If play is detected, comply with paragraphs 2.A. and 2.B.2)a) of the service bulletin. If the fit and dimensions of the components specified in paragraph 2.B.2)a) exceed the tolerances in the applicable structural repair manual, replace with airworthy parts before further flight.

(c) At intervals not to exceed 400 hours time-in-service (TIS) or four calendar months, whichever occurs first, inspect and lubricate the spar tube attachment bolts.

(d) Within 90 calendar days and thereafter at intervals not to exceed 24 calendar months, visually inspect the inside of the horizontal spar tube in accordance with paragraph 2.A. and 2.B.1) of the service bulletin.

(1) If corrosion is found inside the tube, other than in the half-shell area, replace the tube with an airworthy tube within the next 500 hours TIS or 18 calendar months, whichever occurs first.

(2) If corrosion is found inside the tube in the half-shell area, apply a protective treatment as described in paragraph 2.B.1)b) of the service bulletin.

(e) 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, Rotorcraft Standards Staff, FAA, Rotorcraft Directorate. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Standards Staff.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Standards Staff.

(f) 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 helicopter to a location where the requirements of this AD can be accomplished.

(g) The modification shall be done in accordance with Eurocopter France Service Bulletin No. 55.01, Revision 3, dated April 25, 1997. 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 American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 75053-4005. Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 4: The subject of this AD is addressed in Direction Generale De L'Aviation Civile (France) AD 96-277-037(B)R1, dated May 21, 1997.

(h) This amendment becomes effective on July 15, 1998.

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 Eurocopter France Model SA. 315B helicopters was published in the Federal Register on April 21, 1998 (63 FR 19670). That action proposed to require an initial and repetitive visual inspections and modification, if necessary, of the horizontal stabilizer spar tube (spar tube).

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on 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 28 helicopters of U.S. registry would be affected by this proposed AD, that it would take approximately 0.5 work hour per helicopter to accomplish the inspections and 3 work hours per helicopter to accomplish the modification, and that the average labor rate is $60 per work hour. Required parts would cost approximately $1100 per helicopter. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $1310 per helicopter.

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 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: 49 U.S.C. 106(g), 40113, 44701.

39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: