AD 99-17-10

This amendment adopts a new airworthiness directive (AD) applicable to Schweizer Aircraft Corporation (SAC) Model 269A, 269A-1, 269B, 269C, 269C-1, and 269D helicopters. This action requires inspecting the tail rotor swashplate shaft (shaft) nut for looseness and, if loose, inspecting the shaft for proper size; subsequently inspecting the shafts not previously inspected; and replacing any undersized shaft prior to further flight. This amendment is prompted by the discovery of an undersized replacement shaft during routine maintenance. The actions specified in this AD are intended to prevent failure of the shaft and subsequent loss of control of the helicopter.

Final rule; request for comments

99-17-10 SCHWEIZER AIRCRAFT CORPORATION: Amendment 39-11258; Docket No. 99-SW-31-AD;

Applicability: Model 269A, 269A-1, 269B, 269C, 269C-1, and 269D helicopters, with a tail rotor swashplate shaft (shaft), part number (P/N) 269A6049-3, 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 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: Required as indicated, unless accomplished previously.

To prevent failure of the shaft and subsequent loss of control of the helicopter, accomplish the following:

(a) Within the next 10 hours time-in-service (TIS) and thereafter at intervals not to exceed 10 hours TIS until the next 100-hour or annual inspection, whichever occurs first, cut the lockwire; retract the boot on the pitch control assembly; and inspect the shaft nut, P/N 269A6258, for looseness by using a firm hand pressure. If the shaft nut is loose and can be turned by hand, determine if the shaft, P/N 269A6049-3, is undersized in accordance with Part II of Schweizer Aircraft Corp. Service Bulletins B-271, DB-007, or C1B-009, all dated March 12, 1999 (SB), as applicable.

(b) At the next 100-hour or annual inspection, whichever occurs first, inspect the shaft, P/N 269A6049-3, for the proper size, in accordance with Part II of the applicable SB.

(c) Prior to further flight, replace any undersized shaft in accordance with Part II of the applicable SB.

(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, New York 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, New York Aircraft Certification Office.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York 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 inspection shall be done in accordance with Schweizer Aircraft Corp. Service Bulletins B-271, DB-007, or C1B-009, all dated March 12, 1999, 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 Schweizer Aircraft Corporation, P.O. Box 147, Elmira, New York 14902. 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 2, 1999.

This amendment adopts a new AD applicable to SAC Model 269A, 269A-1, 269B, 269C, 269C-1, and 269D helicopters with shaft, part number (P/N) 269A6049-3, installed. The undersized shafts were shipped from the factory as spares between September 1 and December 1, 1998. This action requires the following inspections and replacement:
Within the next 10 hours time-in-service (TIS) and thereafter at intervals not exceeding 10 hours TIS until the next 100-hour or annual inspection, whichever occurs first, inspect the shaft nut, P/N 269A6258, for looseness by using a firm hand pressure. If the shaft nut is loose, inspect the shaft for the proper size.

At the next 100-hour or annual inspection, whichever occurs first, inspect the shaft, P/N 269A6049-3, for the proper size.

Prior to further flight, replace any undersized shaft with an airworthy shaft of the proper size.

This amendment is prompted by the discovery of an undersized replacement shaftduring routine maintenance. The actions specified in this AD are intended to prevent failure of the shaft and subsequent loss of control of the helicopter.

The FAA has reviewed SAC Service Bulletins B-271, DB-007, and C1B-009, all dated March 12, 1999, which describe procedures for inspecting the shaft nut, P/N 269A6258, for looseness by using a firm hand pressure and the shaft, P/N 269A6049-3, for proper size.

Since an unsafe condition has been identified that is likely to exist or develop on other Model 269A, 269A-1, 269B, 269C, 269C-1, and 269D helicopters of the same type design, this AD is being issued to prevent failure of the shaft and subsequent loss of control of the helicopter. This AD requires inspecting the shaft nut, P/N 269A6258, for looseness; inspecting the shaft, P/N 269A6049-3, for the proper size; and replacing any undersized shaft with an airworthy shaft of the proper size. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability of the helicopter. Therefore, inspecting the shaft nut, P/N 269A6528, for looseness is required within the next 10 hours TIS and this AD must be issued immediately.

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

The FAA estimates that 28 helicopters will be affected by this AD. For each helicopter, it will take 0.25 work hour to accomplish the 10-hour inspection, 3.6 work hours to accomplish the inspection and replacement, if necessary, at the 100-hour or annual inspection interval. The average labor rate is $60 per work hour. Required parts will cost approximately $1400 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $45,668.

Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 99-SW-31-AD." The postcard will be date stamped and returned to the commenter.

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.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, 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: