[Federal Register Volume 63, Number 90 (Monday, May 11, 1998)]
[Proposed Rules]
[Pages 25787-25789]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-12383]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-CE-128-AD]
RIN 2120-AA64
Airworthiness Directives; Stemme GmbH & Co. KG Model 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) Model
S10-V sailplanes. The proposed action would require replacing the
propeller blade suspension forks 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
propeller suspension fork failure caused by design deficiency, which,
if not corrected, could result in loss of a propeller blade and loss of
sailplane controllability.
DATES: Comments must be received on or before June 15, 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-128-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,
Federal Republic of Germany. 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-128-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-128-AD, Room 1558, 601 E. 12th Street, Kansas
City, Missouri 64106.
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 S10-V sailplanes. The LBA reports one incident
of a failure of the propeller blade suspension fork during flight,
which caused loss of sailplane controllability. Investigation of this
incident revealed that the thread end groove area of the propeller
blade suspension fork does not have an adequate design. This inadequate
design causes fatigue of the propeller blade suspension fork to the
point of failure.
This condition, if not corrected, could result in loss of the
propeller blade
[[Page 25788]]
during flight and possible loss of sailplane controllability.
Relevant Service Information
Stemme has issued Service Bulletin No. A31-10-020, Am-index: 02.a,
dated October 7, 1996, which specifies procedures for replacing the
propeller blade suspension fork, part number (P/N) 10AP-V08, distance
ring, P/N 10AP-V05, and nut, P/N 10AP-V06, with a new propeller blade
suspension fork of improved design, P/N A09-10AP-V08, a new distance
ring of improved design, P/N A09-10AP-05, and a new nut of improved
design, P/N A09-10AP-V06.
The LBA classified this service bulletin as mandatory and issued
German AD 95-177/2, dated January 30, 1997, 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
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 the Proposed AD
Since an unsafe condition has been identified that is likely to
exist or develop in other Stemme Model S10-V sailplanes of the same
type design registered in the United States, the proposed AD would
require replacing the propeller blade suspension fork, distance ring,
and nut with parts of improved design. Accomplishment of the proposed
installation would be in accordance with Stemme GmbH & Co. KG Service
Bulletin No. A31-10-020, Am-index: 02.a, dated October 7, 1996.
Cost Impact
The FAA estimates that 7 sailplanes in the U.S. registry would be
affected by the proposed AD, that it would take 6 hours per sailplane
to accomplish the proposed action, and that the average labor rate is
approximately $60 an hour. Parts cost approximately $930 per sailplane.
Based on these figures, the total cost impact of the proposed AD on
U.S. operators is estimated to be $9,030.
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-128-AD.
Applicability: Model S10-V sailplanes (serial numbers (S/N) 14-
002 through 14-026, and converted sailplanes S/N 4-003M through 14-
036M), 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 (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 upon the accumulation of 100 hours total
time-in-service (TIS) on the sailplane propeller or within the next
10 hours TIS after the effective date of this AD, whichever occurs
later, unless already accomplished.
To prevent propeller suspension fork failure caused by design
deficiency, which, if not corrected, could result in loss of a
propeller blade and loss of sailplane controllability, accomplish
the following:
(a) Replace the propeller blade suspension fork, part number (P/
N) 10AP-V08 (or an FAA-approved equivalent P/N), with new P/N A09-
10AP-V08 (or an FAA-approved equivalent P/N), distance ring, P/N
10AP-V05 (or an FAA-approved equivalent P/N), with new P/N A09-10AP-
V05 (or an FAA-approved equivalent P/N), and nut, P/N 10AP-V06 (or
an FAA-approved equivalent P/N), with new P/N A09-10AP-V06 (or an
FAA-approved equivalent part number) in accordance with Stemme GmbH
& Co. KG Service Bulletin No. A31-10-020, Am-index: 02.a, dated
October 7, 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 times 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 pages 3 and 4
of Stemme GmbH & Co. KG Service Bulletin, Modification v.p.
propeller/failure blade suspension, No. A31-10-020, Am-index: 02.a,
dated October 7, 1996, should be directed to Stemme GmbH & Co. KG,
Gustav-Meyer-Allee 25, D-13355 Berlin, Federal Republic of Germany.
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 95-177/
2, dated January 30, 1997.
[[Page 25789]]
Issued in Kansas City, Missouri, on May 4, 1998.
Marvin R. Nuss,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-12383 Filed 5-8-98; 8:45 am]
BILLING CODE 4910-13-U
