01-26966. Airworthiness Directives; Bell Helicopter Textron, Inc.-Manufactured Model OH-13E, OH-13H, and OH-13S Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes superseding an existing airworthiness directive (AD) for Model OH-13E, OH-13H, and OH-13S helicopters manufactured by Bell Helicopter Textron, Inc. (BHTI). That AD currently requires either recurring liquid penetrant or eddy current inspections of the main rotor blade grip (grip) threads for a crack. If a crack is detected, that AD requires, before further flight, replacing the cracked grip with an airworthy grip. That AD also establishes a retirement life of 1200 hours time-in-service (TIS) for each grip. This proposed AD would add two part numbers (P/N) to the applicability and requires only recurring eddy current inspections of the grip threads. This proposed AD would also require reporting any results of the grip inspections to the FAA Rotorcraft Certification Office. This proposal is prompted by the issuance of an AD for the civil BHTI Model 47 helicopters and the results of an accident investigation, an operator survey conducted by a trade association, various comments concerning the subject of the current AD, and a further analysis of field service data related to the BHTI Model 47 helicopters. The actions specified by this AD are intended to prevent failure of a grip, loss of a main rotor blade, and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before December 28, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2001-SW-17-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:

Marc Belhumeur, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, Fort Worth, Texas 76193-0170, 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 will be considered before taking action on the proposed rule. The proposals contained in this document 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. 2001-SW-17-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2001-SW-17-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

On May 12, 1987, the FAA issued AD 86-06-08R1, Amendment 39-5260 (52 FR 24135, June 29, 1987) that amended AD 86-06-08, Amendment 39-5626 (51 FR 11300, April 2, 1986) for BHTI Model 47 helicopters. Those ADs required certain fluorescent dye penetrant inspections of each grip. On August 31, 2000, the FAA issued Emergency AD 2000-18-51 for BHTI Model 47 helicopters that superseded AD 86-06-08 and the revision of that AD, 86-06-08R1. AD 2000-18-51 required certain liquid penetrant or eddy current inspections of the grip threads for a crack and, before further flight, replacing any cracked grip with an airworthy grip. That AD also established a retirement life of 1200 hours TIS for each grip. To address the same unsafe condition as addressed for the Model 47 series helicopters, the FAA issued Emergency AD 2001-18-52 on September 1, 2000, for Model OH-13E, OH-13H, and OH-13S helicopters manufactured by BHTI.

Those actions were prompted by the results of an investigation of an August 1998 Canadian accident in which a grip failed on a BHTI Model 47G-2 helicopter due to a fatigue crack. An analysis of field service data revealed fatigue cracks in the majority of the grips inspected. The requirements of AD 2000-18-52 are intended to prevent failure of a grip, loss of a main rotor blade, and subsequent loss of control of the helicopter.

Since issuing AD 2000-18-52, other cracked grips with less than 1200 hours TIS have been discovered, including one grip with a 2-inch crack through the grip. Since then, the FAA has determined that the liquid penetrant inspection is inadequate for finding smaller cracks in the grip threads. Additionally, two parts produced under a Parts Manufacturer Approval (PMA), P/Ns R74-120-252-11 and R74-120-135-5, were inadvertently omitted from the applicability of AD 2000-18-52. Based on these findings, an accident investigation, a further analysis of field service data, and the results of an operator survey conducted by a trade association, the FAA is proposing to supersede AD 2000-18-52. Also, some of these proposals are based on the comments received in response to AD 2000-18-51 and addressed by the FAA in AD 2001-17-17, Amendment 39-12408 (66 FR 45584, August 29, 2001). Those comments pertain to the Model 47 series helicopters as well as the Model OH-13E, OH-13H, and OH-13S helicopters that have the same blade grips installed.

We have identified an unsafe condition that is likely to exist or develop on Model OH-13E, OH-13H, and OH-13S helicopters. The proposed AD would supersede AD 2000-18-52 to require the following:

• For grips, P/N 47-120-135-2, 47-120-135-3, 47-120-135-5, 47-120-252-1, 47-120-252-7, 47-120-252-11, and for grips manufactured under PMA, P/N 74-120-252-11, 74-120-135-5, R74-120-252-11, and R74-120-135-5, conduct eddy current inspections of the threads of both grips as follows:
• Within 300 hours TIS since initial installation on any helicopter or within 10 hours TIS for grips with 300 or more hours TIS, or within 200 hours TIS since last liquid penetrant or eddy current inspection, whichever comes first, conduct an eddy current inspection in accordance with the procedures in Appendix 1 of this AD or an equivalent FAA-approved procedure that contains the requirements of the procedure in Appendix 1. Thereafter, conduct the eddy current inspection at intervals not to exceed 300 hours TIS.
• Report the results of each inspection to the FAA Rotorcraft Certification Office by providing the information requested in the sample format report in Appendix 3 of this AD. Reporting requirements have been approved by the Office of Management and Budget and assigned OMB control number 2120-0056.
• Before further flight, replace any cracked grip with an airworthy grip.

The proposed AD would require maintaining the current retirement life of 1200 hours TIS for each affected grip.

The FAA estimates that 300 helicopters of U.S. registry would be affected by this AD, that it would take approximately 10 work hours per helicopter to accomplish the disassembly, inspection, and reassembly of the grips from the helicopter, and that the average labor rate is $60 per work hour. Required parts, if a grip needs to be replaced, would cost approximately $4,000 per grip. There are two grips on each helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $2,580,000, assuming one inspection per helicopter and replacement of both grips on each helicopter.

The regulations adopted 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 39-11984 and by adding a new airworthiness directive to read as follows:

Continental Copters, Inc.; Gifton McCreay (Formerly Aerodyne Systems Engineering, Ltd., Formerly Texas Helicopter Corp.); Hawkeye Rotor and Wing Flight School; and Teryjon Aviation Inc.: Docket No. 2001-SW-17-AD. Supersedes AD 2000-18-52, Amendment 39-11984, Docket No. 2000-SW-36-AD.

Applicability: Model OH-13E, OH-13H, and OH-13S helicopters manufactured by Bell Helicopter Textron, Inc. (BHTI), with main rotor blade grips, part number (P/N) 47-120-135-2, 47-120-135-3, 47-120-135-5, 47-120-252-1, 47-120-252-7, 47-120-252-11, 74-120-252-11, 74-120-135-5, R74-120-252-11, or R74-120-135-5, 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 (e) 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 main rotor blade grip (grip), separation of a main rotor blade, and subsequent loss of control of the helicopter, accomplish the following:

(a) Conduct an eddy current inspection of the threads of both grips for a crack in accordance with Appendix 1 of this AD or an equivalent FAA-approved procedure containing the requirements of the procedure in Appendix 1 within 300 hours time-in-service (TIS) since initial installation on any helicopter or within 10 hours TIS for grips with 300 or more hours TIS or within 200 hours TIS since the last liquid penetrant or eddy current inspection of grip threads, whichever comes first.

(1) Thereafter, conduct the eddy current inspection in accordance with Appendix 1 of this AD or an equivalent FAA-approved procedure containing the requirements of the procedure in Appendix 1 at intervals not to exceed 300 hours TIS.

(2) Report the results of each inspection to the FAA Rotorcraft Certification Office within 7 calendar days. Reporting requirements have been approved by the Office of Management and Budget and assigned OMB control number 2120-0056.

Note 2:

See Appendix 2 of this AD for a list of known eddy current inspection facilities.

(b) If a crack is detected, before further flight, replace any cracked grip with an airworthy grip.

(c) On or before 1200 hours TIS, replace each grip with an airworthy grip.

(d) This AD establishes a retirement life of 1200 hours TIS for the grips, P/N 47-120-135-2, 47-120-135-3, 47-120-135-5, 47-120-252-1, 47-120-252-7, 47-120-252-11, 74-120-252-11, 74-120-135-5, R74-120-252-11, and R74-120-135-5.

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

Note 3:

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

(f) 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.

Appendix 1

Appendix 2

Partial List of Nondestructive Inspection Testing Facilities Identified by Operators and FAA

Met Chem Testing Laboratories Inc., 369 W. Gregson Ave. (3085 S.), Salt Lake City, Utah 84115-3440, Phone: [phone], Fax: [phone], www.metchemtesting.com.

Galactic NDT Services, 10728 D. South Pipeline RD, Hurst, Texas 76053, Phone: [phone].

Global Testing Technologies, 1173 North Service Rd. Unit D3, Oakville Toronto Canada, Phone: [phone], Fax: [phone].

Paragon Services, Inc., 1015 S. West St., Wichita, KS 67213, Phone: [phone], Fax: [phone].

NOE Services, 8775 E. Orchard Rd. #809, Englewood, CO, Phone: [phone], Fax: [phone].

Applied Technical Services, Inc., 1190 Atlanta Industrial Drive, Marietta, GA 30066, Phone: [phone], Fax: [phone].

Rotorcraft Support, Van Nuys CA 91406, Phone: [phone],

Fax: [phone].

Other FAA Approved repair facilities may be used.

Appendix 3

AD Compliance Inspection Report (Sample Format) Model OH-13 Main Rotor Blade Grip

Provide the following information and mail or fax it to: Manager, Rotorcraft Certification Office, Federal Aviation Administration, Fort Worth, Texas, 76193-0170, USA, Fax: [phone].

Aircraft Registration No:

Helicopter Model:

Helicopter Serial Number:

Owner and Operator of the Helicopter:

	Grip #1	Grip #2
Part Number:
Serial Number:

Hours TIS on the part at Inspection:

Crack Found (Y/N)

If yes, describe below.

Description of Findings

Who performed the inspections?

If a crack was found, describe the crack size, location, and orientation (provide a sketch or pictures with the grip part and serial number).

Provide any other comments.

Issued in Fort Worth, Texas, on October 11, 2001.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.