AD 2001-04-14

This amendment supersedes an existing airworthiness directive (AD) for Societe Nationale Industrielle Aerospatiale (currently Eurocopter France) Model AS350 and AS355 series helicopters that currently requires inspecting the fuselage frame (frame) for a crack at the fuselage-to- tailboom interface and replacing or repairing, as necessary. That AD also requires a fastener torque check and retorquing, as necessary. This amendment retains the requirements of the existing AD but would increase the inspection interval from 1,200 hours time-in-service (TIS) to 2,500 hours or 6 years TIS, whichever occurs first. This amendment revises the time interval for inspecting the frame at the fuselage-to-tailboom interface to coincide with the inspection interval specified in the maintenance manual. The actions specified by this AD are intended to eliminate confusion and unnecessary costs and to prevent a cracked frame, tailboom failure, and subsequent loss of control of the helicopter.

Final rule

2001-04-14 EUROCOPTER FRANCE: Amendment 39-12133. Docket No. 2000-SW-17-AD. Supersedes AD 85-14-06, Amendment 39-5089, and 85-14-06 R1, Amendment 39-5121, Docket No. 85-ASW-15.

Applicability: Model AS350B, AS350B1, AS350B2, AS350B3, AS350BA, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters, certificated in any category.

Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise 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 request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; andif the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To eliminate confusion and unnecessary costs and to prevent a cracked fuselage frame (frame), tailboom failure, and subsequent loss of control of the helicopter, accomplish the following:

(a) Inspect the fuselage-to-tailboom attachment bolts in accordance with paragraph (d) within 30 hours time-in-service (TIS).

(b) Inspect the fuselage-to-tailboom attachment bolts in accordance with paragraph (d) within 30 hours TIS of replacing or reinstalling a tailboom.

(c) Repeat the inspection in accordance with paragraph (d) at intervals not to exceed 2500 hours or 6 years TIS, whichever occurs first.

(d) Inspect the fuselage-to-tailboom attachment bolts for proper torque range and the frame, part number 350A21-1247-00, for a crack at the fuselage-to-tailboom interface.

(1)Procedure for inspecting proper torque range:

(i) Using a fine-point felt tip pen, mark the position of the nut relative to the assembly.

(ii) One at a time, slightly loosen each nut. Do not allow the corresponding bolt to rotate relative to the assembly.

(iii) Tighten the nut with a properly calibrated torque wrench until the mark on the nut lines up with the mark on the assembly.

(iv) Record the torque value required to line up the two marks.

(2) Interpretation of the recorded torque values for each nut:

(i) If the torque value is less than 0.3 mdaN (26 in-lbs) on any nut:

(A) Remove the tailboom.

(B) Perform a dye-penetrant inspection for a crack in the bending radius of the frame.
(C) If a crack is found, repair or replace the frame with an airworthy frame before further flight.
(ii) If the torque value is between 0.3 mdaN and 1 mdaN (26 to 88 in-lbs), re-torque to 0.75 mdaN to 0.9 mdaN (67 to 79 in-lbs).

(iii) If the torque value is equal to or greater than 1 mdaN (88 in-lbs), remove the nut and bolt and replace them with a new nut and bolt. Torque the nut to 0.75 mdaN to 0.9 mdaN (67-79 in-lbs).

Note 2: Aerospatiale Service Bulletins AS 355 No. 05.14 and AS 350 No. 05.16 pertain to the subject of this AD.
(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, Regulations Group, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group.

Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(f) Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the helicopter to a location where the requirements of this AD can be accomplished.

(g) This amendment becomes effective on April 10, 2001.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 85-14-06, Amendment 39-5089 (50 FR 28561, July 15, 1985) and AD 85-14-06 R1, Amendment 39-5121 (50 FR 37173, September 12, 1985), which apply to Societe Nationale Industrielle Aerospatiale (currently Eurocopter France) Model AS350 and AS355 series helicopters, was published in the Federal Register on December 8, 2000 (65 FR 76953). That action proposed the same actions as the existing AD's and also proposed increasing the inspection interval from 1,200 hours TIS to 2,500 hours or 6 years TIS, whichever occurs first, to coincide with the maintenance manual and eliminate confusion and unnecessary costs. To compensate for the increase in the inspection interval, reducing the initial inspection interval from 100 hours TIS to 30 hours TIS and changing the visual inspection to a dye-penetrant inspection were also proposed.

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 475 helicopters of U.S. registry will be affected by this AD, that it will take approximately 8 work hours per helicopter 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 this AD on U.S. operators is estimated to be $228,000, assuming no cracked frames are discovered.

The regulations adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.

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 FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas.

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, 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 removing Amendment 39-5089 (50 FR 28561, July 15, 1985) and Amendment 39-5121 (50 FR 37173, September 12, 1985), and by adding a new airworthiness directive (AD), Amendment 39-12133, to read as follows: