AD 99-16-13

This amendment supersedes an existing airworthiness directive (AD), applicable to MDHI Model MD-900 helicopters, that currently requires applying specified serial numbers and establishing life limits for certain parts. This amendment is prompted by additional analysis that supports an increase in the life limit of certain parts. The actions specified by this AD are intended to increase the life limits for various parts.

Final rule

99-16-13 MD HELICOPTERS, INC.: Amendment 39-11248. Docket No. 98-SW-42-AD. Supersedes AD 97-13-09, Amendment 39-10056, Docket No. 96-SW-35-AD.

Applicability: MD-900 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 (d) 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: Requiredas indicated, unless accomplished previously.

To establish appropriate life limits for various parts, accomplish the following:

(a) On or before attaining the following life limits, remove from service:

(1) The nonrotating swashplate assembly, part number (P/N) 900C2010192-105, -107, -109, or -111, on or before 1,800 hours time-in-service (TIS).

(2) The collective drive link assembly, P/N 900C2010207-101, on or before 3,307 hours TIS.

(3) The self-aligning, spherical/slider main rotor bearing, P/N 900C3010042-103, on or before 2,030 hours TIS.

(4) The vertical stabilizer control system (VSCS) bellcrank assembly, P/N 900FP341712-103, and bellcrank arm, P/N 900F2341712-101, on or before 2,700 hours TIS.

(b) On or before 100 hours TIS after July 10, 1997, or before October 31, 1999, whichever occurs first:

(1) For Model MD-900 helicopters with serial numbers (S/N) 900-00002 through 900-00012, apply the appropriate S/N to the mid-forward trussassembly, P/N 900F2401200-102, and the forward and aft deck-fitting assemblies, P/N 900F2401500-103 and 900F2401600-103.

(2) For Model MD-900 helicopters with S/N 900-00002 through 900-00048, apply S/N to the left and right VSCS bellcrank assemblies, P/N 900F2341712-101 and 900FP341712-103, and the mid-aft truss strut assembly, P/N 900F2401300-103.

(3) Apply the S/N as specified in paragraphs (b)(1) and (b)(2) of this AD adjacent to the existing P/N in accordance with the Accomplishment Instructions of MDHS Service Bulletin No. 900-039, Revision 2, dated March 12, 1997.

(c) This AD revises the Airworthiness Limitations Section of the MD-900 Maintenance Manual by increasing the retirement lives for certain parts.

NOTE 2: The Airworthiness Limitations Section of the MD-900 Rotorcraft Maintenance Manual, Reissue 1, Revision 2, dated July 24, 1998, pertains to the subject of this AD.

(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, Los Angeles Aircraft Certification Office. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Los Angeles Aircraft Certification Office.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles Aircraft Certification Office.

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

(f) The application of the serial numbers shall be done in accordance with the Accomplishment Instructions of McDonnell Douglas Helicopter Systems Service Bulletin No. 900-039, Revision 2, dated March 12, 1997. This incorporation by referenceof that document was previously approved by the Director of the Federal Register, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51, as of July 10, 1997 (62 FR 34163). Copies may be obtained from MD Helicopters Inc., Attn: Customer Support Division, 5000 E. McDowell Rd., Mail Stop M615-GO48, Mesa, Arizona 85215-9797, telephone 1-800-388-3378 or 480-891-6342, datafax 480-891-6782. 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.

(g) This amendment becomes effective on September 10, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 97-13-09, Amendment 39-10056 (62 FR 34163, June 25, 1997), which is applicable to MDHI Model MD-900 helicopters, was published in the Federal Register on April 28, 1999 (64 FR 22818). That action proposed to require increasing the life limit of various parts and correcting an incorrect part number that was listed in AD 97-13-09. That action also proposed to require, as in AD 97-13-09, applying serial numbers to certain parts and establishing a life limit for the vertical stabilizer control system bellcrank assembly.

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. However, since the publicationof the Notice of Proposed Rulemaking, the name of the type certificate holder has changed from "McDonnell Douglas Helicopter Systems" to "MD Helicopter, Inc." This final rule reflects that change; the FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

The FAA estimates that 27 helicopters will be affected by this AD, that it will take approximately 2.5 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 the AD on U.S. operators is estimated to be $4,050.

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 Administrationamends 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 39-10056 (62 FR 34163, June 25, 1997), and by adding a new airworthiness directive (AD), Amendment 39-11248, to read as follows: