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Proposed Rule

Airworthiness Directives; LET Aeronautical Works Model L-13 “Blanik” Sailplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

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AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes to adopt a new airworthiness directive (AD) that would apply to all LET Aeronautical Works (LET) Model L-13 “Blanik” sailplanes. The proposed AD would require you to inspect the tail-fuselage hinge for strength requirements and damage, and would require you to replace any hinge with damage or that does not meet strength requirements. The proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the Czech Republic. The actions specified by the proposed AD are intended to detect and correct any tail-fuselage hinge that is damaged or has inadequate material characteristics. Any tail-fuselage hinge Start Printed Page 48649with damage or inadequate material characteristics could fail and result in loss of controlled flight.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before September 6, 2000.

ADDRESSES:

Submit comments in triplicate to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-CE-91-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. You may inspect comments at this location between 8 a.m. and 4 p.m., Monday through Friday, except holidays.

You may get the service information referenced in the proposed AD from LET Aeronautical Works, Kunovice 686 04, Czech Republic; telephone: +420 632 55 44 96; facsimile: +420 632 56 41 13. You may examine this information at the Rules Docket at the address above.

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FOR FURTHER INFORMATION CONTACT:

Mike Kiesov, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64016; telephone: (816) 329-4144; facsimile: (816) 329-4090.

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SUPPLEMENTARY INFORMATION:

Comments Invited

How Do I Comment on This AD?

We invite your comments on the proposed rule. You may submit whatever written data, views, or arguments you choose. You need to include the rule's docket number and submit your comments in triplicate to the address specified under the caption ADDRESSES. We will consider all comments received on or before the closing date specified above, before taking action on the proposed rule. We may change the proposals contained in this notice in light of the comments received.

How Can We Communicate More Clearly With You?

The FAA specifically invites comments on the overall regulatory, economic, environmental, and energy aspects of the proposed rule that might necessitate a need to modify the proposed rule. You may examine all comments we receive. We will file a report in the Rules Docket that summarizes each FAA contact with the public that concerns the substantive parts of this proposal.

The FAA is reexamining the writing style we currently use in regulatory documents, in response to the Presidential memorandum of June 1, 1998. That memorandum requires federal agencies to communicate more clearly with the public. We are interested in your comments on the ease of understanding this document, and any other suggestions you might have to improve the clarity of FAA communications that affect you. You can get more information about the Presidential memorandum and the plain language initiative at http://www.faa.gov/​language/​

How Can I Be Sure FAA Receives My Comment?

If you want us to acknowledge the receipt of your comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 99-CE-91-AD.” We will date stamp and mail the postcard back to you.

Discussion

What Has Happened so Far?

The Civil Aviation Authority (CAA), which is the airworthiness authority for the Czech Republic, recently notified the FAA that an unsafe condition may exist on all LET Model L-13 “Blanik” sailplanes. The CAA reports an incident involving one of the affected sailplanes where the tail-fuselage attachment fitting was damaged. Further analysis reveals that the material characteristics of the tail-fuselage attachment fitting were inadequate.

What Are the Consequences if the Condition Is Not Corrected?

The tail-fuselage attachment fitting is a primary structural element within the empennage. Failure of this part, if not detected and corrected, could result in loss of controlled flight.

Relevant Service Information

Is There Service Information That Applies to This Subject?

LET has issued Mandatory Bulletin No. L13/085a, dated November 17, 1999.

What Are the Provisions of This Service Bulletin?

The service bulletin describes procedures for testing the tail-fuselage attachment fittings, part number (P/N) A 102 021N.

What Action Did the CAA Take?

The CAA classified this service bulletin as mandatory and issued CAA AD Number CAA-AD-T-112/1999, dated November 18, 1999, in order to assure the continued airworthiness of these sailplanes in the Czech Republic.

Was This in Accordance With the Bilateral Airworthiness Agreement?

This sailplane model is manufactured in the Czech Republic and the FAA type certificated it for operation in the United States under the provisions of § 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Complying with this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above.

The FAA's Determination and an Explanation of the Provisions of the Proposed AD

What Has FAA Decided?

The FAA has examined the findings of the CAA; reviewed all available information, including the service information referenced above; and determined that:

—The unsafe condition referenced in this document exists or could develop on other LET Model L-13 “Blanik” sailplanes of the same type design;

—These sailplanes should have the actions specified in the above service bulletin incorporated; and

—The FAA should take AD action in order to correct this unsafe condition.

What Does This Proposed AD Require?

This proposed AD would require you to inspect the tail-fuselage hinge for strength requirements and damage, and would require you to replace any hinge with damage or that does not meet strength requirements.

What Are the Differences Between the CAA AD and the Proposed AD?

The Czech CAA requires the fitting test before the next flight. We propose a requirement that you test the hinge part within 60 days after the effective date of the proposed AD. The FAA does not have justification to ground all sailplanes until this fitting test is accomplished. We believe that 60 days will give the owners/operators of the affected sailplanes enough time to have the proposed actions accomplished without compromising the safety of the sailplanes.

Cost Impact

How Many Sailplanes Does This Proposed AD Impact?

We estimate that the proposed AD would affect 140 sailplanes in the U.S. registry.

What Is the Cost Impact of the Proposed Inspection for the Affected Sailplanes on the U.S. Register?

We estimate that it would take approximately 4 workhours per sailplane to accomplish the proposed inspection, at an average labor rate of $60 an hour. Based on the cost factors Start Printed Page 48650presented above, we estimate the total cost impact of the proposed inspection on U.S. operators to be $33,600, or $240 per sailplane.

What Is the Cost Impact of the Proposed Replacement for the Affected Sailplanes on the U.S. Register?

We estimate that it would take approximately 16 workhours per sailplane to accomplish the proposed replacement (as necessary), at an average labor rate of $60 an hour. The manufacturer will provide the replacement attachment fittings at no cost. Based on the cost factors presented above, we estimate the total labor cost impact of the proposed replacement on U.S. operators to be $960 per sailplane.

Regulatory Impact

How Does This AD Impact Relations Between Federal and State Governments?

The proposed regulations would 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. It is determined that this proposed rule would not have federalism implications under Executive Order 13132.

How Does This AD Involve a Significant Rule or Regulatory Action?

For the reasons discussed above, I certify that this action (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under Department of Transportation Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if put into effect, 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. We have placed a copy of the draft regulatory evaluation prepared for this action in the Rules Docket. You may obtain a copy of it by contacting the Rules Docket at the location provided under the caption ADDRESSES.

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List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration (FAA) 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:

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

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[Amended]

2. FAA amends § 39.13 by adding a new airworthiness directive (AD) to read as follows:

LET Aeronautical Works: Docket No. 99-CE-91-AD.

(a) What sailplanes are affected by this AD? This AD applies to Model L-13 “Blanik” sailplanes, all serial numbers, certificated in any category.

(b) Who must comply with this AD? Anyone who wishes to operate any of the above sailplanes on the U.S. Register must comply with this AD.

(c) What problem does this AD address? The actions specified by this AD are intended to prevent the tail-fuselage hinge failing and consequent loss of controlled flight.

(d) What must I do to address this problem? To address this problem, you must accomplish the following actions:

ActionsCompliance timesProcedures
(1) Inspect the tail-fuselage attachment fitting, part number (P/N) A 102 021N, for damage and material hardness.Within 60 days after the effective date of the AD.Follow the procedures in Mandatory Bulletin No. L13/085a, dated November 17, 1999.
(2) If the tail-fuselage attachment fitting is damaged or the material does not meet the hardness requirements specified in the service bulletin you must replace the tail-fuselage attachment fitting.Before further flight after the inspection.You must notify LET Aeronautical Works and request they send the replacement part with installation instructions.
(3) Do not install, on any sailplane, a P/N A 102 021N attachment fitting that has not passed the inspection requirements specified in paragraph (d)(1) of this AD.As of the effective date of this AD.Inspect any attachment fitting in accordance with the previously referenced service bulletin.

(e) Can I comply with this AD in any other way? You may use an alternative method of compliance or adjust the compliance time if:

(1) Your alternative method of compliance provides an equivalent level of safety; and

(2) The Manager, Small Airplane Directorate approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106.

Note:

This AD applies to each sailplane identified in paragraph (a) of this AD, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For sailplanes 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. You should include in the request an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if you have not eliminated the unsafe condition, specific actions you propose to address it.

(f) Where can I get information about any already-approved alternative methods of compliance? You can contact Mike Kiesov, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64016; telephone: (816) 329-4144; facsimile: (816) 329-4090.

(g) What if I need to fly the sailplane to another location to comply with this AD? The FAA can issue a special flight permit under sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate your sailplane to a location where you can accomplish the requirements of this AD.

(h) How do I get copies of the documents referenced in this AD? You may obtain copies of the documents referenced in this AD from LET Aeronautical Works, Kunovice 686 04, Czech Republic; telephone: +420 632 55 44 96; facsimile: +420 632 611 26; or may examine this document at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

Note:

The subject of this AD is addressed in CAA AD Number CAA-AD-T-112/1999, dated November 18, 1999.

Start Signature

Issued in Kansas City, Missouri, on August 1, 2000.

Marvin R. Nuss,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 00-20175 Filed 8-8-00; 8:45 am]

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