[Federal Register Volume 65, Number 154 (Wednesday, August 9, 2000)]
[Proposed Rules]
[Pages 48648-48650]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-20175]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-CE-91-AD]
RIN 2120-AA64


Airworthiness Directives; LET Aeronautical Works Model L-13 
``Blanik'' Sailplanes

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

[[Page 48649]]

with 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.

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.

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 Sec. 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

[[Page 48650]]

presented 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

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:

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.


Sec. 39.13  [Amended]

    2. FAA amends Sec. 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:

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


    Issued in Kansas City, Missouri, on August 1, 2000.
Marvin R. Nuss,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-20175 Filed 8-8-00; 8:45 am]
BILLING CODE 4910-13-U