[Federal Register Volume 63, Number 13 (Wednesday, January 21, 1998)]
[Proposed Rules]
[Pages 3054-3056]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-1298]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-127-AD]
RIN 2120-AA64


Airworthiness Directives; Stemme GmbH & Co. KG Models S10 and 
S10-V 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 Stemme GmbH & Co. KG (Stemme) Models 
S10 and S10-V sailplanes. The proposed AD would require replacing the 
horizontal stabilizer rear fittings with parts of improved design. The 
proposed AD is the result of mandatory continuing airworthiness 
information (MCAI) issued by the airworthiness authority for Germany. 
The actions specified by the proposed AD are intended to prevent 
structural failure of the horizontal stabilizer caused by cracked rear 
fittings, which could result in reduced sailplane controllability.

DATES: Comments must be received on or before February 23, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 97-CE-127-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 may be obtained 
from Stemme GmbH & Co. KG, Gustav-Meyer-Allee 25, D-13355 Berlin, 
Germany; telephone: 49.33.41.31.11.70; facsimile: 49.33.41.31.11.73. 
This information also may be examined at the Rules Docket at the 
address above.

FOR FURTHER INFORMATION CONTACT: Mr. Mike Kiesov, Aerospace Engineer, 
Small Airplane Directorate, Aircraft Certification Service, FAA, 1201 
Walnut, suite 900, Kansas City, Missouri 64106; telephone (816) 426-
6934; 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. 97-CE-127-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 Regional Counsel, Attention: 
Rules Docket No. 97-CE-127-AD, Room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106.

Discussion

    The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority 
for Germany, notified the FAA that an unsafe condition may exist on 
certain Stemme S10 and S10-V sailplanes. The LBA reports that 
operational loads are causing internal stress on the welds of the rear 
fitting of the horizontal stabilizer of the above-referenced 
sailplanes.
    This condition, if not detected and corrected, could result in 
failure of the horizontal stabilizer with possible reduced sailplane 
controllability.

Relevant Service Information

    Stemme has issued Service Bulletin No. A31-10-022, dated August 16, 
1996, which specifies procedures for inspecting the horizontal 
stabilizer rear fittings for cracks and replacing any cracked fittings 
with parts of improved design obtained from Stemme; and also specifies 
revising the maintenance manual.

[[Page 3055]]

    The LBA classified this service bulletin as mandatory and issued 
German AD 96-300, effective October 24, 1996, in order to assure the 
continued airworthiness of these sailplanes in Germany.

The FAA's Determination

    This sailplane model is manufactured in Germany and is 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 this 
type design that are certificated for operation in the United States.

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Stemme Model S10 and S10-V sailplanes of the 
same type design registered in the United States, the FAA is proposing 
AD action. The proposed AD would require replacing the horizontal 
stabilizer rear fittings with parts of improved design. Accomplishment 
of the proposed installation would be in accordance with the service 
information previously referenced.

Differences Between the Service Bulletin, German AD, and This 
Proposed AD

    Stemme Service Bulletin No. A31-10-022, dated August 16, 1996, and 
German AD No. 96-300, effective October 24, 1996, both require 
inspecting the horizontal stabilizer fittings for cracks and replacing 
the fittings if found cracked. Stemme Service Bulletin No. A31-10-022 
specifies changing the maintenance manual to include repetitive 
inspections of these fittings.
    The FAA's policy is to provide corrective action that will 
eliminate the need for repetitive inspections. The FAA has determined 
that long-term operational safety will be better assured by design 
changes that remove the source of the problem, rather than by 
repetitive inspections or other special procedures.
    Because replacing the horizontal stabilizer rear fittings with 
parts of improved design on the affected sailplanes eliminates the need 
for repetitive inspections, the proposed AD differs from the service 
bulletin and German AD in that it would mandate replacement of the 
horizontal stabilizer rear fittings.

Cost Impact

    The FAA estimates that 9 sailplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 3 
workhours per sailplane to accomplish the proposed replacement, and 
that the average labor rate is approximately $60 an hour. Parts cost 
approximately $200 per sailplane. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$3,420.

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:

Stemme GmbH & Co. KG: Docket No. 97-CE-127-AD.

    Applicability: The following sailplane models and serial 
numbers, certificated in any category:

------------------------------------------------------------------------
               Models                             Serial Nos.           
------------------------------------------------------------------------
S10.................................  10-03 through 10-63.              
S10V................................  14-002 through 14-026 and         
                                       transformed S10V airplanes with  
                                       serial numbers of 14-012M through
                                       14-063M.                         
------------------------------------------------------------------------

    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 (c) 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 within the next 25 hours time-in-service 
(TIS) after the effective date of this AD, unless already 
accomplished.
    To prevent structural failure of the horizontal stabilizer 
caused by cracked rear fittings, which could result in reduced 
sailplane controllability, accomplish the following:
    (a) Replace the horizontal stabilizer rear fittings with 
improved design fittings in accordance with the instructions in 
Stemme Service Bulletin No. A31-10-022, dated August 16, 1996.
    (b) 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.
    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an equivalent level of safety may be 
approved by the Manager, Small Airplane Directorate, FAA, 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 compliance with this AD, if any, may be 
obtained from the Small Airplane Directorate.

    (d) Questions or technical information related to Stemme Service 
Bulletin No. A31-10-022 dated August 16, 1996, should be directed to 
Stemme GmbH & Co. KG, Gustav-Meyer-Allee 25, D-13355 Berlin, 
Germany;

[[Page 3056]]

telephone: 49.33.41.31.11.70; facsimile: 49.33.41.31.11.73. This 
service information may be examined at the FAA, Central Region, 
Office of the Regional Counsel, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

    Note 3: The subject of this AD is addressed in German AD 96-300, 
dated October 24, 1996.

    Issued in Kansas City, Missouri, on January 12, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-1298 Filed 1-20-98; 8:45 am]
BILLING CODE 4910-13-U