[Federal Register Volume 63, Number 227 (Wednesday, November 25, 1998)]
[Rules and Regulations]
[Pages 65057-65060]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-31434]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-106-AD; Amendment 39-10917; AD 98-24-30]
RIN 2120-AA64


Airworthiness Directives; Stemme GmbH & Co. KG Models S10, S10-V, 
and S10-VT Sailplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to certain Stemme GmbH & Co. KG (Stemme) Models S10, S10-V, and 
S10-VT sailplanes. This AD requires inspecting certain areas in the 
flight control system for cracks; immediately replacing any cracked 
parts; and eventually replacing all longitudinal coupling with modified 
coupling regardless if found cracked. This AD is the result of 
mandatory continuing airworthiness information (MCAI) issued by the 
airworthiness authority for Germany. The actions specified by this AD 
are intended to detect and correct cracks in certain areas of the 
flight control system, which could result in flight control system 
failure with consequent reduced or loss of control of the sailplane.

DATES: Effective December 18, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 18, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before December 28, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket 98-CE-106-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.
    Service information that applies to this AD may be obtained from 
Stemme GmbH & Co. KG, Gustav-Meyer-Allee 25, D-13355 Berlin, Federal 
Republic of Germany; telephone: 49.33.41.31.11.70; facsimile: 
49.33.41.31.11.73. This information may also be examined at the Federal 
Aviation Administration (FAA), Central Region, Office of the Regional 
Counsel, Attention: Rules Docket 98-CE-106-AD, Room 1558, 601 E. 12th 
Street, Kansas City, Missouri 64106; or at the Office of the Federal 
Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mr. Mike Kiesov, Aerospace Engineer, 
FAA, Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City, 
Missouri 64106; telephone: (816) 426-6934; facsimile: (816) 426-2169.

SUPPLEMENTARY INFORMATION:

Discussion

    The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority 
for Germany, recently notified the FAA that an unsafe condition may 
exist on certain Stemme Models S10, S10-V, and S10-VT sailplanes. The 
LBA reports that cracks were found on the flight control longitudinal 
coupling during a static load test on the elevator control system.
    The cracks were such that the flight control system would have most 
likely failed in a short period of operating time with reduced or loss 
of control of the sailplane.

[[Page 65058]]

    Other parts in the flight control system have the same type of 
force intersection design and cracks could exist or develop in these 
areas also. These areas are the wing flap coupling, part number (P/N) 
10SW-RVW; the airbrake control coupling, P/N 10SB-RVW; the flap drive 
rocker, P/N 10SW-RMW; and the flap/aileron interference shaft, P/N 
10SQ-RMW.
    Cracks in any of these areas, if not detected and corrected in a 
timely manner, could result in flight control system failure with 
consequent reduced or loss of control of the sailplane.

Relevant Service Information

    Stemme has issued Service Bulletin A31-10-032, Amendment-Index 
02.a, dated July 10, 1998, which specifies procedures for inspecting 
the following parts for cracks:
     The flight control longitudinal coupling, part number (P/
N) 10SH-RVH;
     The wing flap coupling, P/N 10SW-RVW;
     The airbrake control coupling, P/N 10SB-RVW;
     The flap drive rocker, P/N 10SW-RMW; and
     The flap/aileron interference shaft, P/N 10SQ-RMW.
    This service bulletin also references Stemme Installation 
Instructions A34-10-032-E, Amendment-Index 01.a, dated August 10, 1998, 
which includes procedures for replacing the flight control longitudinal 
coupling, with modified P/N 10SH-RVH coupling.
    The LBA classified this service information as mandatory and issued 
German AD 1998-323, dated July 1, 1998, in order to assure the 
continued airworthiness of these sailplanes in Germany.

The FAA's Determination

    These sailplane models are manufactured in Germany and are type 
certificated 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. 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 This AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Stemme Models S10, S10-V, and S10-VT 
sailplanes of the same type design registered for operation in the 
United States, the FAA is taking AD action. This AD requires inspecting 
the areas of the flight control system previously referenced for 
cracks; immediately replacing any cracked parts; and eventually 
replacing all longitudinal coupling with modified coupling regardless 
if found cracked.
    Accomplishment of the inspection will be required in accordance 
with Stemme Service Bulletin A31-10-032, Amendment-Index 02.a, dated 
July 10, 1998.
    Accomplishment of the longitudinal coupling replacement will be 
required in accordance with Stemme Installation Instructions A34-10-
032-E, Amendment-Index 01.a, dated August 10, 1998.
    Accomplishment of the replacement of any other cracked part in the 
flight control system will be required in accordance with procedures 
obtained from the manufacturer through the FAA, Small Airplane 
Directorate.

Possible Follow-up Action

    Stemme has modified the longitudinal coupling, but has not modified 
the wing flap coupling, the airbrake control coupling, the flap drive 
rocker, and the flap/aileron interference shaft. If cracks are found on 
parts other than the longitudinal coupling, then Stemme will develop 
modified parts upon demand as quickly as possible. Operation of the 
sailplane while the parts are being developed will not be allowed. The 
FAA has determined that this alternative is better than operating the 
sailplane with cracked parts in the flight control system.
    The FAA will continue to monitor this situation, and may issue 
additional AD action to require mandatory replacement of modified 
flight control system parts other than the longitudinal coupling, as 
these parts become available.

Compliance Time of This AD

    The replacement compliance of this AD is presented in calendar time 
and hours time-in-service (TIS). Cracks in the flight control system 
occur because of sailplane operation; however, there is a potential for 
corrosion in this area, which could enhance crack growth. For this 
reason, the FAA has determined that requiring the replacement at 6 
calendar months will assure the safety of the low-usage sailplanes; and 
requiring the replacement at 100 hours TIS will assure the safety of 
the high-usage sailplanes. The prevalent compliance time will be that 
which occurs first.

Differences Between This AD, the Service Information, and the 
German AD

    Stemme Service Bulletin A31-10-032, Amendment-Index 02.a, dated 
July 10, 1998, specifies inspecting certain areas of the flight control 
system coupling prior to further flight on sailplanes with over 100 
hours TIS. The German AD requires this on all sailplanes registered for 
operation in Germany.
    The FAA does not have the justification to require the initial 
inspection prior to further flight on all sailplanes with over 100 
hours TIS. The FAA is giving a grace period of 5 hours TIS for those 
sailplanes that have more than 100 hours TIS on the flight control 
system.

Determination of the Effective Date of the AD

    Since a situation exists (possible flight control system failure) 
that requires the immediate adoption of this regulation, it is found 
that notice and opportunity for public prior comment hereon are 
impracticable, and that good cause exists for making this amendment 
effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting immediate flight safety and, thus, was not 
preceded by notice and opportunity to comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 will be considered, 
and this rule may be amended in light of the comments received. Factual 
information that supports the commenter's ideas and suggestions is 
extremely helpful in evaluating the effectiveness of the AD action and 
determining whether additional rulemaking action would be needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before

[[Page 65059]]

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 AD will be filed in 
the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 98-CE-106-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and is not a significant regulatory action under 
Executive Order 12866. It has been determined further that this action 
involves an emergency regulation under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979). If it is determined that 
this emergency regulation otherwise would be significant under DOT 
Regulatory Policies and Procedures, a final regulatory evaluation will 
be prepared and placed in the Rules Docket (otherwise, an evaluation is 
not required). A copy of it, if filed, may be obtained from the Rules 
Docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

98-24-30  STEMME GMBH & Co. KG: Amendment 39-10917; Docket No. 98-
CE-106-AD.

    Applicability: The following models and serial number 
sailplanes, certificated in any category:

------------------------------------------------------------------------
             Model                           Serial numbers
------------------------------------------------------------------------
S10...........................  10-03 through 10-63.
S10-V.........................  14-002 through 14-030 and transformed
                                 S10-V sailplanes with serial numbers of
                                 14-012M through 14-063M.
S10-VT........................  11-001, 11-004 through 11-013, and 11-
                                 015.
------------------------------------------------------------------------

    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 (f) 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 detect and correct cracks in certain areas of the flight 
control system, which could result in flight control system failure 
with consequent reduced or loss of control of the sailplane, 
accomplish the following:
    (a) Upon accumulating 100 hours time-in-service (TIS) on the 
flight control system or within the next 5 hours TIS after the 
effective date of this AD, whichever occurs later, inspect the 
following areas in the flight control system, in accordance with the 
Instructions section of Stemme Service Bulletin A31-10-032, 
Amendment-Index 02.a, dated July 10, 1998:
    (1) The longitudinal coupling, part number (P/N) 10SH-RVH;
    (2) The wing flap coupling, P/N 10SW-RVW;
    (3) The airbrake control coupling, P/N 10SB-RVW;
    (4) The flap drive rocker, P/N 10SW-RMW; and
    (5) The flap/aileron interference shaft, P/N 10SQ-RMW.
    (b) Prior to further flight after the inspection required by 
paragraph (a) of this AD, replace any cracked part with a modified 
part.
    (1) Obtain modified parts (including installation instructions), 
except for the longitudinal coupling, from the manufacturer through 
the FAA, Small Airplane Directorate, at the address specified in 
paragraph (e) of this AD.
    (2) Obtain modified longitudinal coupling from the manufacturer 
as specified in Stemme Service Bulletin A31-10-032, Amendment-Index 
02.a, dated July 10, 1998; and install this modified longitudinal 
coupling in accordance with Stemme Installation Instructions A34-10-
032-E, Amendment-Index 01.a, dated August 10, 1998.

    Note 2: Stemme Service Bulletin A31-10-032, Amendment-Index 
02.a, dated July 10, 1998, includes a return form for reporting the 
findings of the crack inspection required by paragraph (a) of this 
AD. The FAA encourages all owners/operators of the affected 
sailplanes to have this form filled out and send it to the 
manufacturer at the address specified in paragraph (g) of this AD.

    (c) Within the next 6 calendar months after the effective date 
of this AD or within the next 100 hours TIS after the effective date 
of this AD, whichever occurs first, unless already accomplished 
(compliance with the applicable part of paragraph (b) of this AD), 
obtain modified longitudinal coupling from the manufacturer as 
specified in Stemme Service Bulletin A31-10-032, Amendment-Index 
02.a, dated July 10, 1998; and install this modified longitudinal 
coupling in accordance with Stemme Installation Instructions A34-10-
032-E, Amendment-Index 01.a, dated August 10, 1998.
    (d) As of the effective date of this AD, no person may install 
on any affected sailplane, longitudinal coupling that has not been 
modified as specified in Stemme Service Bulletin A31-10-032, 
Amendment-Index 02.a, dated July 10, 1998; and installed in 
accordance with Stemme Installation Instructions A34-10-032-E, 
Amendment-Index 01.a, dated August 10, 1998.
    (e) Special flight permits may be issued in accordance with 
Secs. 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.
    (f) 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Small Airplane Directorate.

    (g) Questions or technical information related to the service 
information referenced in this AD should be directed to Stemme GmbH 
& Co. KG, Gustav-Meyer-Allee 25, D-13355 Berlin, Federal Republic of 
Germany; 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.
    (h) The inspection required by this AD shall be done in 
accordance with Stemme

[[Page 65060]]

Service Bulletin A31-10-032, Amendment-Index 02.a, dated July 10, 
1998. The longitudinal coupling replacement required by this AD 
shall be done in accordance with Stemme Installation Instructions 
A34-10-032-E, Amendment-Index 01.a, dated August 10, 1998. This 
incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Stemme GmbH & Co. KG, Gustav-Meyer-
Allee 25, D-13355 Berlin, Federal Republic of Germany. Copies may be 
inspected at the FAA, Central Region, Office of the Regional 
Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at 
the Office of the Federal Register, 800 North Capitol Street, NW, 
suite 700, Washington, DC.

    Note 4: The subject of this AD is addressed in German AD 1998-
323, dated July 1, 1998.

    (i) This amendment becomes effective on December 18, 1998.

    Issued in Kansas City, Missouri, on November 17, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate,
Aircraft Certification Service.
[FR Doc. 98-31434 Filed 11-24-98; 8:45 am]
BILLING CODE 4910-13-U