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Proposed Rule

Airworthiness Directives; Eurocopter Deutschland GMBH Model BO-105CB-5 and BO-105CBS-5 Helicopters

Document Details

Information about this document as published in the Federal Register.

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Start Preamble

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to Eurocopter Deutschland GMBH (ECD) Model BO-105CB-5 and BO-105CBS-5 helicopters. That AD currently requires, before further flight, creating a component log card or equivalent record and determining the calendar age and number of flights on each tension-torsion (TT) strap. This action would establish a life limit for certain main rotor TT straps. This proposal is prompted by a need to establish a life limit for certain TT straps because of an accident in which a main rotor blade (blade) separated from an ECD Model MBB-BK 117 helicopter due to fatigue failure of a TT strap. The same part-numbered TT strap is used on the ECD Model BO-105 helicopters. The actions specified by this AD are intended to prevent fatigue failure, loss of a blade, and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before May 12, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 99-SW-65-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

The service information referenced in the proposed rule may be obtained from American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-3527. This information may be examined at the FAA, Office of the Regional Counsel, Southwest Region, Room 663, Fort Worth, Texas.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Charles Harrison, Aerospace Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, Fort Worth, Texas 76193-0110, telephone (817) 222-5128, fax (817) 222-5961.

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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 Start Printed Page 13252summarizing 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 comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 99-SW-65-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. 99-SW-65-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

On November 10, 1999, the FAA issued AD 99-24-05, Amendment 39-11429 (64 FR 62973, November 18, 1999), applicable to ECD Model BO-105CB-5 and BO-105CBS-5 helicopters. That AD currently requires, before further flight, creating a component log card or equivalent record and determining the calendar age and number of flights on each tension-torsion (TT) strap. AD 99-24-05 also requires inspecting and removing, as necessary, certain unairworthy TT straps. That action was prompted by an accident in which a blade separated from an ECD Model MBB-BK 117 helicopter due to fatigue failure of a TT strap. The same part numbered TT strap is also used on the ECD Model BO-105CB-5 and BO-105CBS-5 helicopters. The requirements of that AD are intended to prevent failure of a TT strap, loss of a blade, and subsequent loss of control of the helicopter.

Since the issuance of that AD, the FAA has determined the need to establish a life limit for the TT strap. ECD has issued Alert Service Bulletin BO 105 No. ASB-BO 105-10-113, Revision 1, dated August 31, 1999 (ASB), which specifies establishing a life limit. The ASB specifies that part number (P/N) 2604067 be renumbered as 117-14110 and P/N J17322-1 be renumbered as 117-14111. The ASB also specifies replacing TT strap, part number (P/N) 117-14110 and 117-14111, at intervals not to exceed 120 months after initial installation on any ECD Model BO-105CB-5, BO-105CBS-5, or MBB-BK 117 helicopter or every 25,000 flights, whichever occurs first. The LBA classified this ASB as mandatory and issued AD 1999-289/2, dated September 1, 1999, to ensure the continued airworthiness of these helicopters in the Federal Republic of Germany.

Since an unsafe condition has been identified on the MBB-BK-117 that is likely to exist or develop on the ECD Model BO-105CB-5 and BO-105CBS-5 helicopters, registered in the United States, the proposed AD would require establishing a life limit effective January 1, 2001, for the TT straps of 120 months or 25,000 flights, whichever occurs first.

The FAA estimates that 200 helicopters of U.S. registry would be affected by this proposed AD, that it would take approximately 16 work hours per helicopter to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $10,400 per helicopter. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $2,272,200.

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 does 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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

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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:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. Section 39.13 is amended by removing Amendment 39-11429 (64 FR 62973, November 18, 1999), and by adding a new airworthiness directive (AD), to read as follows:

Eurocopter Deutschland GMBH: Docket No. 99-SW-65-AD. Supersedes AD 99-24-05, Amendment 39-11429, Docket No. 99-SW-58-AD.

Applicability: Model BO-105CB-5 and BO-105CBS-5 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 (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 fatigue failure of a TT strap, loss of a main rotor blade (blade), and subsequent loss of control of the helicopter, accomplish the following:

(a) On or before January 1, 2001, remove any TT strap, part number (P/N) 117-14110 or 117-14111, that has been in service 120 months since initial installation or accumulated 25,000 flights (a flight is a takeoff and a landing), on any Model BO-105CB-5, BO-105CBS-5, or MBB-BK-117 helicopter, and replace the TT strap with an airworthy TT strap.

(b) Before further flight,

(1) Create a component log card or equivalent record for each TT strap, P/N 2604067 or J17322-1, by:

(i) Reviewing the history of each helicopter and TT strap.

(ii) Determining the age since initial installation on any helicopter (age) and the number of flights on each TT strap.

(A) To determine the initial number of flights on a TT strap if the time-in-service (TIS) is known and if the number of flights is unknown, multiply the total number of hours TIS by 5 to obtain the number of flights.

(B) If a TT strap has been previously used at any time on Model BO-105 helicopters not affected by this AD, multiply the number of flights accumulated on those other models by a factor of 0.625 and add that result to the number of flights accumulated on the Model BO-105CB-5 and BO-105CBS-5 helicopters. Start Printed Page 13253

(iii) Entering both the age and the number of flights on the component log card or equivalent record.

(2) Remove any TT strap from service if:

(i) The total hours TIS or number of flights and age cannot be determined, or

(ii) The TT strap has either accumulated 25,000 or more flights or has an age equal to or greater than 120 months.

(3) Inspect any TT strap with an age less than 120 months that has accumulated less than 25,000 flights in accordance with paragraph 2.B.2 of the “Accomplishment Instructions,” of Eurocopter Deutschland GMBH Alert Service Bulletin BO 105 No. ASB-BO 105-10-113, Revision 1, dated August 31, 1999 (ASB).

(i) If a defect is found, remove the TT strap from service.

(ii) If no defect is found, reidentify TT strap P/N 2604067 or J17322-1 before installing in accordance with the “Accomplishment Instructions,” paragraph 2.B.1.2., of the ASB.

(c) When any TT strap is replaced because of age, usage, or defect, before further flight, reidentify the main rotor head and TT straps in accordance with the “Accomplishment Instructions,” paragraph 2.B.1.2., of the ASB.

(d) This AD revises the Airworthiness Limitations Section of the maintenance manual by establishing a life limit for the TT strap of 120 months or 25,000 flights, whichever occurs first.

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

Note 2:

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

(f) 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.

Note 3:

The subject of this AD is addressed in the Luftfahrt Bundesamt (Federal Republic of Germany) AD 1999-289/2, dated September 1, 1999.

Start Signature

Issued in Fort Worth, Texas, on March 6, 2000.

Henry A. Armstrong,

Manager, Rotorcraft Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 00-6037 Filed 3-10-00; 8:45 am]

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