04-3495. Airworthiness Directives; Schweizer Aircraft Corporation Model 269A, 269A-1, 269B, 269C, and TH-55A Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes to revise an existing airworthiness directive (AD) for Schweizer Aircraft Corporation (Schweizer) Model 269A, 269A-1, 269B, 269C, and TH-55A helicopters. That AD currently requires inspecting the lugs on certain aft cluster fittings and each aluminum end fitting on certain tailboom struts. Modifying or replacing each strut assembly within a specified time period and serializing certain strut assemblies is also required. Additionally, a one-time inspection and repair, if necessary, of certain additional cluster fittings, and replacement and modification of certain cluster fittings within 150 hours time-in-service (TIS) or 6 months, whichever occurs first, is required. This action would require the same actions as the existing AD, but would revise the Applicability section of the AD. This proposal is prompted by the discovery of an error in the Applicability section of the existing AD. The actions specified by the proposed AD are intended to prevent failure of a tailboom support strut or a cluster fitting, which could cause rotation of a tailboom into the main rotor blades, and subsequent loss of control of the helicopter.

DATES:

Comments must be received by April 19, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2002-SW-25-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: [e-mail]. Comments may be inspected at the Office of the Regional Counsel between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

George Duckett, Aviation Safety Engineer, FAA, New York Aircraft Certification Office, Airframe and Propulsion Branch, 10 Fifth Street, 3rd Floor, Valley Stream, New York, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their mailed comments submitted in response to this proposal must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2002-SW-25-AD.” The postcard will be date stamped and returned to the commenter.

Discussion

On June 24, 2003, the FAA issued AD 2003-13-15, Amendment 39-13217 (68 FR 40478, July 8, 2003), to require owners and operators of the affected helicopters to:

• Within 10 hours TIS and thereafter at intervals not to exceed 50 hours TIS, dye-penetrant inspect the lugs and replace any cracked cluster fitting;
• Within 150 hours TIS or 6 months, whichever occurs first, replace or modify, using kit, part number (P/N) SA-269K-106-1, each cluster fitting, P/N 269A2234 and P/N 269A2235;
• For strut assemblies, P/N 269A2015 or P/N 269A2015-5, at intervals not to exceed 50 hours TIS, visually inspect the strut aluminum end fittings for deformation or damage, dye-penetrant inspect the strut aluminum end fittings for a crack, and replace deformed, damaged, or cracked parts. Within 500 hours TIS or one year, whichever occurs first, modify or replace certain part-numbered strut assemblies;
• Within 100 hours TIS, for Model 269C helicopters, serialize each strut assembly, P/N 269A2015-5 and 269A2015-11;
• Within 25 hours TIS or 60 days, whichever occurs first, inspect and repair cluster fittings, P/N 269A2234-3 and P/N 269A2235-3; and
• Before further flight, replace any cluster fitting that is cracked or has a surface defect beyond rework limits.

That action was prompted by the need to expand the applicability to include certain Hughes-manufactured cluster fittings and to provide a terminating action for the repetitive dye-penetrant inspections of the cluster fittings. That condition, if not corrected, could result in failure of a tailboom support strut or a cluster fitting, which could cause rotation of a tailboom into the main rotor blades, and subsequent loss of control of the helicopter.

Since issuing that AD, we have discovered an error in the Applicability section that should be changed. The AD currently excepts helicopters that have Hughes-manufactured cluster fittings installed and that were originally sold by Hughes after June 1, 1988. We intended that this exception apply to all cluster fittings, P/N 269A2234-3 or P/N 269A2235-3, that are installed, regardless of the manufacturer, if there was written documentation in the aircraft or manufacturer's records that shows the cluster fitting was originally sold by the manufacturer after June 1, 1988. Therefore, we are now proposing to expand the exception to all cluster fittings originally sold after June 1, 1988, regardless of the manufacturer.

The previously described unsafe condition is likely to exist or develop on other helicopters of the same type designs. Therefore, the proposed AD would revise AD 2003-13-15 to retain the current requirements but revise the Applicability to exclude all cluster fittings with appropriate written documentation showing that the cluster fitting was originally sold by the manufacturer after June 1, 1988.

The FAA estimates that 1,000 helicopters of U.S. registry would be affected by the proposed AD. It would take approximately 2.5 work hours for each dye-penetrant inspection, 12 work hours to replace one cluster fitting, 4 work hours to modify or replace the strut assembly, 0.25 work hours to serialize the strut assembly, and 16 work hours to modify a cluster fitting. The average labor rate is $65 per work hour. Required parts would cost approximately $5 for each fitting inspection, $1,635 to replace a cluster fitting, $1,500 to modify or replace the strut assembly, and $1,688 for each cluster fitting modification kit (2 cluster fittings). Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $2,369,248 (assuming 2,000 cluster fittings are inspected, 50 cluster fittings are replaced, 6 strut assemblies are modified or replaced, 6 strut assemblies are serialized, and 1,010 cluster fittings are modified).

The regulations proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 39-13217 (68 FR 40478, July 8, 2003), and by adding a new airworthiness directive (AD), to read as follows:

Schweizer Aircraft Corporation: Docket No. 2002-SW-25-AD. Revises AD 2003-13-15, Amendment 39-13217.

Applicability: Model 269A, 269A-1, 269B, 269C, and TH-55A helicopters, certificated in any category, with a tailboom support strut (strut) assembly, part number (P/N) 269A2015 or 269A2015-5; or with a center frame aft cluster fitting, P/N 269A2234 or 269A2235, and an aft cluster fitting listed in the following table:

Helicopter model number	Helicopter serial number	With aft cluster fitting, P/N
Model 269C	0570 through 1165	269A2234-3.
Model 269C	0500 through 1165	269A2235-3.
Model 269A, A-1, B, or C, or TH-55A	All	269A2234-3 or 269A2235-3.

Exception: For the Model 269A, A-1, B, or C or TH-55A helicopters with cluster fittings, P/N 269A2234-3 or P/N 269A2235-3, installed, if there is written documentation in the aircraft or manufacturer's records that shows the cluster fitting was originally sold by the manufacturer after June 1, 1988, the requirements of this AD are not applicable.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of a tailboom support strut or lug on a cluster fitting, which could cause rotation of a tailboom into the main rotor blades, and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 10 hours time-in-service (TIS), and thereafter at intervals not to exceed 50 hours TIS, for helicopters with cluster fittings, P/N 269A2234 or P/N 269A2235:

(1) Using paint remover, remove paint from the lugs on each cluster fitting. Wash with water and dry. The tailboom support strut must be removed prior to the paint stripping.

(2) Dye-penetrant inspect the lugs on each cluster fitting. See the following Figure 1:

(3) If a crack is found, before further flight, replace the cracked cluster fitting with an airworthy cluster fitting.

(b) Cluster fittings, P/N 269A2234 and P/N 269A2235, that have NOT been modified with Kit P/N SA-269K-106-1, are NOT eligible replacement parts.

(c) Within 150 hours TIS or 6 months, whichever occurs first, replace each cluster fitting, P/N 269A2234 and P/N 269A2235, with an airworthy cluster fitting or modify each cluster fitting, P/N 269A2234 and P/N 269A2235, with Kit, P/N SA-269K-106-1. Installing the kit is terminating action for the 50-hour TIS repetitive dye-penetrant inspection for these cluster fittings. Broken or cracked cluster fittings are not eligible for the kit modification.

(d) For helicopters with strut assemblies, P/N 269A2015 or 269A2015-5, accomplish the following:

(1) At intervals not to exceed 50 hours TIS:

(i) Remove the strut assemblies, P/N 269A2015 or P/N 269A2015-5.

(ii) Visually inspect the strut aluminum end fittings for deformation or damage and dye-penetrant inspect the strut aluminum end fittings for a crack in accordance with Step II of Schweizer Service Information Notice No. N-109.2, dated September 1, 1976 (SIN N-109.2).

(iii) If deformation, damage, or a crack is found, before further flight, modify the strut assemblies by replacing the aluminum end fittings with stainless steel end fittings, P/N 269A2017-3 and -5, and attach bolts in accordance with Step III of SIN N-109.2; or replace each strut assembly P/N 269A2015 with P/N 269A2015-9, and replace each strut assembly P/N 269A2015-5 with P/N 269A2015-11.

(2) Within 500 hours TIS or one year, whichever occurs first, modify or replace the strut assemblies in accordance with paragraph (d)(1)(iii) of this AD.

(e) For the Model 269C helicopters, within 100 hours TIS, serialize each strut assembly, P/N 269A2015-5 and P/N 269A2015-11, in accordance with Schweizer Service Information Notice No. N-108, dated May 21, 1973.

(f) Within 25 hours TIS or 60 days, whichever occurs first, for cluster fittings, P/N 269A2234-3 and P/N 269A2235-3, perform a one-time inspection and repair, if required, in accordance with Procedures, Part II of Schweizer Service Bulletin No. B-277, dated January 25, 2002.

(g) Before further flight, replace any cluster fitting that is cracked or has surface defects beyond rework limits with an airworthy cluster fitting.

(h) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Manager, New York Aircraft Certification Office (NYACO), Engine and Propeller Directorate, FAA, for information about previously approved alternative methods of compliance.

Issued in Fort Worth, Texas, on February 9, 2004.

David A. Downey,

Manager, Rotorcraft Directorate, Aircraft Certification Service.