AD 2000-20-18

This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 407 helicopters. This AD requires inspecting the brackets that attach each horizontal stabilizer slat (slat) to the stabilizer for a crack and replacing the slat assembly if a crack is found. Installing airworthy segmented slat assemblies would be required prior to flight after December 31, 2000 and would constitute terminating action for the requirements of this AD. This amendment is prompted by an incident in which a slat separated from a helicopter. The actions specified by this AD are intended to prevent a slat from separating, impact with a main or tail rotor blade, and subsequent loss of control of the helicopter.

Final rule

2000-20-18 BELL HELICOPTER TEXTRON CANADA: Amendment 39-11930. Docket No. 2000-SW-24-AD.
Applicability: Model 407 helicopters, serial numbers 53000 through 53347, 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 (c) 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; and if 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 prevent a horizontal stabilizer slat (slat) from separating, impact with a main or tail rotor blade, and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 50 hours time-in-service (TIS) and thereafter at intervals not to exceed 100 hours TIS, visually inspect the brackets, part number (P/N) 206-023-119-109 or -110 or P/N 407-023-801-127 or -128, that attach the slats, P/N 407-023-002-117, to the horizontal stabilizer for a crack.

(1) If any crack is found, replace the slat assembly, P/N 407-023-002-117, with an airworthy segmented slat assembly, P/N 407-023-001-101, before further flight. Replace the slat assembly in accordance with Part II of the Accomplishment Instructions in Bell Helicopter Textron Alert Service Bulletin No. ASB 407-99-32, dated December 7, 1999.

(2) If no crack is found, replace each slat assembly, P/N 407-023-002-117, with an airworthy segmented slat assembly, P/N 407-023-001-101, prior to flight after December 31, 2000.

(b) Installing airworthy segmented slat assemblies, P/N 407-023-001-101, constitutes terminating action for the requirements of this AD.

(c) 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(d) 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.

(e) The modification shall be done in accordance with Part II of the Accomplishment Instructions in Bell Helicopter Textron Alert Service Bulletin No. ASB 407-99-32, dated December 7, 1999. 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 Bell Helicopter Textron Canada, 12,800 Rue de l'Avenir, Mirabel, Quebec JON1LO, telephone (450) 437-2862 or (800) 363-8023, fax (450) 433-0272. 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.

(f) This amendment becomes effective on November 22, 2000.

NOTE 3: The subject of this AD is addressed in Transport Canada (Canada) AD CF-2000-09, dated March 21, 2000.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) that applies to BHTC Model 407 helicopters was published in the Federal Register on July 20, 2000 (65 FR 44994). That action proposed to require visually inspecting certain brackets that attach slots to the horizontal stabilizer for a crack and replacing any slat assembly that has a cracked bracket. Also proposed was installing different part-numbered airworthy segmented slat assemblies on all affected models prior to flight after December 31, 2000.

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 348 helicopters of U.S. registry will be affected by this AD, that it will take approximately 0.5 work hour per helicopter to perform the visual inspections, 1 work hour to replace a slat assembly, and that the average labor rate is $60 per work hour. Required parts will cost approximately $2,364 per segmented slat assembly. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $1,697,544, assuming 1 inspection per helicopter and replacement of the 2 slat assemblies on each helicopter.

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 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: