[Federal Register Volume 61, Number 238 (Tuesday, December 10, 1996)]
[Proposed Rules]
[Pages 65006-65008]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31269]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-CE-35-AD]
RIN 2120-AA64


Airworthiness Directives; Glasflugel Models Standard Libelle and 
Standard Libelle 201 B Sailplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive 
(AD) that would apply to certain Glasflugel Models Standard Libelle and 
Standard Libelle 201 B sailplanes. The proposed action would require 
inspecting the aileron operating lever actuating shaft welded seams for 
cracks and modifying or replacing the actuating shaft if cracked. 
Cracks found in the welded seams of the actuating shaft prompted the 
proposed action. The actions specified by the proposed AD are intended 
to prevent cracks in the aileron operating lever's actuating shaft 
welded seams, which, if not detected and corrected, could cause loss of 
control of the sailplane.

DATES: Comments must be received on or before February 12, 1997.

ADDRESSES: Send comments on the proposal in triplicate to the Federal 
Aviation Administration (FAA), Central Region, Office of the Assistant 
Chief Counsel, Attention: Rules Docket No. 96-CE-35-AD, Room 1558, 601 
E. 12th Street, Kansas City, Missouri 64106. Comments may be inspected 
at this location between 8 a.m. and 4 p.m., Monday through Friday, 
holidays excepted.
    Service information that applies to the proposed AD is available 
from Glasflugel, c/o H. Streifeneder, Glasfaser-Flugzeug Service GmbH, 
Hofener Weg, D-72582 Grabenstetten, Germany. This information also may 
be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. J. Mike Kiesov, Project Officer, 
Sailplanes, FAA, Small Airplane Directorate, 1201 Walnut, suite 900, 
Kansas City, Missouri 64106; telephone (816) 426-6932, facsimile (816) 
426-2169.

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 that summarizes 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. 96-CE-35-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, Central Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 96-CE-35-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Events Leading to the Proposed Action

    The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority 
for Germany, recently notified the FAA that an unsafe condition may 
exist on certain Glasflugel Models Standard Libelle and Standard 
Libelle 201 B sailplanes. The LBA has received reports of cracks 
developing in the aileron operating lever's welded seams. These are 
fatigue cracks that are occurring because of the adverse loading that 
takes place during the rigging and derigging operation, if the aileron 
control has not first been disconnected. This condition, if not 
detected and corrected, could result in the aileron operating lever 
breaking, causing total loss of aileron control.
    Glasflugel has issued Glasfaser-Flugzeug-Service GmbH Technical 
Note (TN) 201-33, dated March 4, 1996, which specifies procedures for 
inspecting for cracks, and repairing and modifying the aileron 
operating lever's welded seams, or replacing the lever with a new 
reinforced part.
    The LBA classified this technical note as mandatory and issued AD 
LTA-Nr.: 96-116, dated March 18, 1996, in order to ensure the continued 
airworthiness of these sailplanes in Germany.

Explanation of the Provisions of this AD

    These sailplane models are manufactured in Germany and are type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, the LBA has kept the FAA informed of 
the situation described above. The FAA has examined the findings of the 
LBA, reviewed all available information including the service 
information referenced above, and determined that AD action is 
necessary for products of

[[Page 65007]]

this type design that are certificated for operation in the United 
States.
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Glasflugel Models Standard Libelle and 
Standard Libelle 201 B sailplanes of the same type design registered in 
the United States, the proposed AD would require inspecting the aileron 
operating lever's actuating shaft welded seams for cracks. If cracks 
are found, the proposal specifies repairing and modifying, or replacing 
the actuating shaft. If no cracks are found, the actuating shaft would 
have to be modified or replaced within the next 8 calendar months from 
the date of the proposed initial inspection.

Related Service Information

    Accomplishment of the proposed installation would be in accordance 
with Glasfaser-Flugzeug-Service GmbH Technical Note (TN) 201-33, dated 
March 4, 1996.

Proposed Compliance Time

    The compliance time of the proposed AD is in calendar time instead 
of hours time-in-service (TIS). The average monthly usage of the 
affected sailplanes ranges throughout the fleet. For example, one owner 
may operate the sailplane 25 hours TIS in one week, while another 
operator may operate the sailplane 25 hours TIS in one year. In order 
to ensure that all of the affected sailplanes do not have cracked 
shafts, and do have the improved aileron operating lever's welded seams 
incorporated within a reasonable amount of time, the FAA is proposing a 
compliance time of within the next 30 calendar days after the effective 
date of the AD, for the initial action (inspection, and possible 
repair, modification or replacement), and if no cracks are found on the 
initial inspection, accomplishing the modification or replacement 
within the next 8 calendar months after the effective date of the 
proposed AD.

Cost Impact

    The FAA estimates that 108 sailplanes in the U.S. registry would be 
affected by the proposed AD; that it would take approximately 4 
workhours per sailplane to accomplish the inspection, repair and 
modification; or that it would take 3 workhours per sailplane to 
inspect and replace the lever; and that the average labor rate is 
estimated to be approximately $60 an hour. Material cost for the 
modification is approximately $10 per sailplane, and a replacement 
shaft part costs $140 per sailplane. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$27,000 ($250 per sailplane) if all shafts are modified, or $34,560 
($320 per sailplane) if all shafts are replaced. The FAA has no way to 
determine how many owners/operators have accomplished this action.

Regulatory Impact

    The regulations proposed herein 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    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 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 has been placed 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.


Sec. 39.13  [Amended]

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

Glasflugel: Docket No. 96-CE-35-AD.

    Applicability: Models Standard Libelle and Standard Libelle 201 
B Sailplanes (all serial numbers), certificated in any category.

    Note 1: This AD applies to each sailplane identified in the 
preceding applicability provision, 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 (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 in the body of this AD, unless 
already accomplished.
    To prevent cracks in the aileron operating lever's actuating 
shaft welded seams, which if not detected and corrected, could cause 
loss of control of the sailplane, accomplish the following:
    (a) Within the next 30 calendar days after the effective date of 
this AD, inspect for cracks in the aileron operating lever's 
actuating shaft welded seams in accordance with Method 1 of the 
Accomplishment section in Glasfaser-Flugzeug-Service GmbH 
(Glasfaser) Technical Note (TN) 201-33, dated March 4, 1996.
    (1) If cracks are found, prior to further flight, either:
    (i) Remove the shaft, repair the cracked welded seams and modify 
the shaft in accordance with Method 2 of the Accomplishment section 
in Glasfaser TN 201-33, dated March 4, 1996; or,
    (ii) Remove and replace the shaft with a new Glasflugel 
reinforced shaft in accordance with drawing 201-47-3-1 from 
Glasfaser TN 201-33, dated March 4, 1996.
    (2) If no cracks are found, within the next 8 calendar months 
after the inspection required by paragraph (a) of this AD, either:
    (i) Modify the aileron operating lever in accordance with Method 
2 of the Accomplishment section of Glasfaser TN 201-33, dated March 
4, 1996; or,
    (ii) Remove and replace the shaft with a new Glasflugel 
reinforced shaft in accordance with drawing 201-47-3-1 from 
Glasfaser TN 201-33, dated March 4, 1996.
    (b) After completing any action described in paragraph (a) or 
any sub-paragraph of (a) in this AD, check and adjust (if 
applicable) the aileron deflection range in accordance with the 
``Remarks'' paragraph in Glasfaser TN 201-33, dated March 4, 1996.
    (c) 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 sailplane to a location where 
the requirements of this AD can be accomplished.
    (d) An alternative method of compliance or adjustment of the 
compliance times that provides an equivalent level of safety may be 
approved by the Manager, Small Airplane Directorate, 1201 Walnut, 
suite 900, Kansas City, Missouri 64106.
    The request shall be forwarded through an appropriate FAA 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Small Airplane Directorate.

    Note 2: Information concerning the existence of approved 
alternative methods of

[[Page 65008]]

compliance with this AD, if any, may be obtained from the Small 
Airplane Directorate.

    (e) All persons affected by this directive may obtain copies of 
the document referred to herein upon request to Glasflugel, c/o H. 
Streifeneder, Glasfaser-Flugzeug Service GmbH, Hofener Weg, D-72582 
Grabenstetten, Germany; or may examine this document at the FAA, 
Central Region, Office of the Assistant Chief Counsel, Room 1558, 
601 E. 12th Street, Kansas City, Missouri 64106.

    Issued in Kansas City, Missouri, on December 2, 1996.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 96-31269 Filed 12-9-96; 8:45 am]
BILLING CODE 4910-13-U