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

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2001-25-52, which was sent previously to all known U.S. owners and operators of Schweizer Aircraft Corporation (Schweizer) Model 269A, 269A-1, 269B, 269C, and TH-55A helicopters by individual letters. This AD supersedes an existing AD that requires inspecting and modifying or replacing, if necessary, the aluminum end fittings of each tailboom support strut (strut). That AD also requires inspecting the tailboom center attach fittings and center frame aft cluster fittings for damage, and if damaged parts are found, replacing the damaged parts. This AD requires inspecting and replacing, if necessary, each strut clevis lug (lug) on each tailboom center frame aft cluster fitting (cluster fitting), certain strut assemblies, certain tailboom attachments, and certain frame aft cluster fittings. Modifying or replacing each strut assembly within a certain time period and serializing certain strut assemblies are also required. This AD is prompted by an accident in the United Kingdom involving the in-flight structural failure of a Schweizer Model 269C helicopter. The actions specified by this AD are intended to prevent failure of a lug on a cluster fitting, rotation of a tailboom into the main rotor blades, and subsequent loss of control of the helicopter.

DATES:

Effective May 8, 2002, to all persons except those persons to whom it was made immediately effective by Emergency AD 2001-25-52, issued on December 14, 2001, which contained the requirements of this amendment.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of May 8, 2002.

Comments for inclusion in the Rules Docket must be received on or before June 24, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2001-SW-58-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: 9-asw-adcomments@faa.gov.

The applicable service information may be obtained from Schweizer Aircraft Corporation, P.O. Box 147, Elmira, New York 14902. This information may be examined 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.

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 (516) 256-7525, fax (516) 568-2716.

SUPPLEMENTARY INFORMATION:

The FAA issued AD 76-18-01 (41 FR 37093, September 2, 1976) on August 23, 1976, which amended AD No. 73-3-1 (38 FR 2331). AD 76-18-01 required visually inspecting the aluminum end fittings of each strut for deformation or damage and dye-penetrant inspecting for a crack and, if deformation, damage or a crack is found, modifying or replacing the part. Modifying or replacing the parts within specified hours time-in-service (TIS) is also required. Also, that AD requires inspecting the tailboom center attach fittings and center frame aft cluster fittings for damage, and if damaged parts are found, replacing the damaged parts.

Since the issuance of that AD, an accident occurred in the United Kingdom involving an in-flight structural failure of a Schweizer Model 269C helicopter. The Air Accidents Investigation Branch of the United Kingdom investigated the accident and recommended that the FAA issue an AD requiring certain inspections of the clevis lugs and replacing certain cluster fittings. The FAA determined that the unsafe condition was due to cracking of the cluster fitting. Therefore, on December 14, 2001, the FAA issued AD 2001-25-52 to supersede AD 76-18-01. AD 2001-25-52 retains the inspection, modification and replacement requirements of the strut, but adds a requirement to dye-penetrant inspect the lugs on both cluster fittings within 10 hours TIS and at specified intervals, and, before further flight, replace any cracked cluster fitting.

The FAA has reviewed Schweizer Service Information Notice No. N-109.2, dated, September 1, 1976, which describes procedures for inspecting tailboom support strut aluminum end fittings and replacing aluminum end fittings with stainless steel end fittings. The FAA has also reviewed Schweizer Service Information Notice No. N-108, dated May 21, 1973, which describes procedures for serializing the tailboom support strut assembly.

Since the unsafe condition described is likely to exist or develop on other Schweizer Model 269A, 269A-1, 269B, 269C, and TH-55A helicopters of the same type designs, the FAA issued Emergency AD 2001-25-52 to prevent failure of a lug on a cluster fitting, rotation of a tailboom into the main rotor blades, and subsequent loss of control of the helicopter. The AD requires the following:

• Initially and at specified intervals, inspect the lugs on both cluster fittings, certain strut assemblies, certain tail boom attachments and center frame aft cluster fittings. If damage or a crack is found, before further flight replace each damaged or cracked part with an airworthy part;
• Modify or replace each strut assembly within the specified TIS or one year, whichever occurs first; and
• Serialize certain strut assemblies.

The actions must be accomplished in accordance with the service information notices described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity of the helicopter. Therefore, the actions previously stated are required at the specified time intervals, and this AD must be issued immediately.

Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual letters issued on December 14, 2001 to all known U.S. owners and operators of Schweizer Model 269A, 269A-1, 269B, 269C, and TH-55A helicopters. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to 14 CFR 39.13 to make it effective to all persons.

The FAA estimates that 500 helicopters of U.S. registry will be affected by this AD. It will 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, and 0.25 work hours to serialize the strut assembly. The average labor rate is $60 per work hour. Required parts will cost approximately $5.00 for each fitting inspection, $1635 to replace a cluster fitting, and $1500 to modify or replace the strut assembly. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $283,280 (assuming 1000 cluster fittings are inspected, 50 cluster fittings are replaced, 6 strut assemblies are modified or replaced, and 6 strut assemblies are serialized).

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 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 mailed 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. 2001-SW-58-AD.” The postcard will be date stamped and returned to the commenter.

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.

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.

2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

2001-25-52 Schweizer Aircraft Corporation: Amendment 39-12726. Docket No. 2001-SW-58-AD. Supersedes AD 76-18-01, Amendment No. 39-2707, Docket No. 72-WE-23-AD.

Applicability: Model 269A, 269A-1, 269B, 269C, and TH-55A helicopters, with tailboom support strut (strut) assemblies, part number (P/N) 269A2015 or P/N 269A2015-5; tailboom center attach fitting, P/N 269A2324; or with a center frame aft cluster fitting, P/N 269A2234 or 269A2235, 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 a strut clevis lug (lug) on a center frame aft cluster fitting (cluster fitting), 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 269A2235:

(1) Using paint remover, remove paint from the lugs on each aft cluster fitting. Wash with water and dry.

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

(3) If a crack is found, before further flight, replace the cracked cluster fitting with an airworthy cluster fitting. Cluster fittings, P/N 269A2234 and 269A2235, are not eligible to replace a cracked cluster fitting.

(b) 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 with accordance 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 (b)(1)(iii) of this AD.

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

(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 (NYACO), FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, NYACO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the NYACO.

(e) 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.

(f) The inspections and modifications shall be done in accordance with Steps II and III of Schweizer Service Information Notice No. N-109.2, dated September 1, 1976 and Schweizer Service Information Notice No. N-108, dated May 21, 1973, 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 May 8, 2002, to all persons except those persons to whom it was made immediately effective by Emergency AD 2001-25-52, issued December 14, 2001, which contained the requirements of this amendment.