[Federal Register Volume 64, Number 139 (Wednesday, July 21, 1999)]
[Proposed Rules]
[Pages 39100-39102]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-18630]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-CE-25-AD]
RIN 2120-AA64
Airworthiness Directives; Stemme GmbH & Co. KG Models S10-V and
S10-VT 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 all Stemme GmbH & Co. KG (Stemme) Models S10-V
and S10-VT sailplanes that incorporate a certain propeller blade
suspension fork. The proposed AD would require repetitively exchanging
(through the manufacturer) the propeller blade suspension fork for a
propeller blade suspension fork that has passed X-ray crack testing
requirements. 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
detect and correct fractured propeller blade suspension forks, which
could result in the loss of a propeller blade during flight with
possible lateral imbalance and loss of thrust.
DATES: Comments must be received on or before August 30, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Regional Counsel,
Attention: Rules Docket No. 99-CE-25-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,
FAA, Small Airplane Directorate, 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
[[Page 39101]]
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. 99-CE-25-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. 99-CE-25-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 all Stemme Models S10-V and S10-VT sailplanes. The LBA reports
the loss of the propeller blade on one of the affected sailplanes
during flight. Analysis of this propeller blade reveals a fracture
located at the end of the threaded fastening pin.
This condition, if not detected and corrected, could result in
lateral imbalance and loss of thrust.
Relevant Service Information
Stemme has issued Service Bulletin No. A31-10-051, Amendment 01.a,
pages 3 and 4, dated March 6, 1999, which specifies repetitively
exchanging (through the manufacturer) the propeller blade suspension
fork for a propeller blade suspension fork that has passed X-ray crack
testing requirements.
The LBA classified this service bulletin as mandatory and issued
German AD 1999-224, dated June 4, 1999, 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 Models S10-V and S10-VT sailplanes of
the same type design registered in the United States, the FAA is
proposing AD action. The proposed AD would require repetitively
exchanging (through the manufacturer) the part number (P/N) A09-10AP-
V08 (or FAA-approved equivalent part number) propeller blade suspension
fork for one of these P/N forks that has passed X-ray crack testing
requirements.
Relationship of the Proposed AD With AD 98-15-24
AD 98-15-24, Amendment 39-10674 (63 FR 39484), requires replacing
the P/N 10AP-V08 propeller blade suspension fork with a P/N A09-10AP-
V08 propeller blade suspension fork on Stemme Model S10-V sailplanes.
The proposed AD is only written against those sailplanes with a P/N
A09-10AP-V08 fork installed because the compliance time of the proposed
AD is such that all affected sailplanes would have to comply with AD
98-15-24 before the proposed AD (if followed with a final rule) would
become effective. With this in mind, none of the affected sailplanes
would have a P/N 10AP-V08 propeller blade suspension fork installed at
the time the proposed AD would need to be complied with.
Both the P/N A09-10AP-V08 and the P/N 10AP-V08 propeller blade
suspension forks are part of the P/N 10AP-V08 propeller system
configuration.
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 12
workhours to remove and re-install the propeller blade suspension
forks, and that the average labor rate is approximately $60 an hour.
There is no cost to the operator to exchange the propeller blade
suspension forks other than the labor costs. Based on these figures,
the total cost impact of the proposed initial propeller blade
suspension fork exchange on U.S. operators is estimated to be $6,480,
or $720 per sailplane.
These figures only take into the account the costs of the initial
propeller blade suspension fork exchange and do not take into account
the costs of any repetitive propeller blade suspension fork exchanges.
The FAA has no way of determining the number of repetitive propeller
blade exchanges each owner/operator would incur over the life of his/
her affected sailplane or until a terminating action is developed.
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.
[[Page 39102]]
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. 99-CE-25-AD.
Applicability: Models S10-V and S10-VT 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 (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 as presented below:
--Initial Compliance: Upon accumulating 100 hours time-in-service
(TIS) on a part number (P/N) A09-10AP-V08 (or FAA-approved
equivalent part number) propeller blade suspension fork or within
the next 10 hours TIS after the effective date of this AD, whichever
occurs later, unless already accomplished; and
--Repetitive Compliance: Within 50 hours TIS after the initial
compliance time and thereafter at intervals not to exceed 50 hours
TIS.
Note 2: AD 98-15-24, Amendment 39-10674 (63 FR 39484), requires
replacing the P/N 10AP-V08 (or FAA-approved equivalent part number)
propeller blade suspension fork with a P/N A09-10AP-V08 fork on
Stemme Model S10-V sailplanes. This AD is only applies to those
sailplanes with a P/N A09-10AP-V08 fork installed because the
compliance time of this AD is such that all the Stemme Model S10-V
sailplanes would have to comply with AD 98-15-24 before this AD
becomes effective. Both the P/N A09-10AP-V08 and the P/N 10AP-V08
propeller blade suspension forks are part of the P/N 10AP-V08
propeller system configuration.
To detect and correct fractured propeller blade suspension
forks, which could result in the loss of a propeller blade during
flight with possible lateral imbalance and loss of thrust,
accomplish the following:
(a) At the initial and repetitive compliance times, exchange
(through the manufacturer) the propeller blade suspension fork for a
P/N A09-10AP-V08 propeller blade suspension fork that has passed X-
ray crack testing requirements; and install the propeller blade
suspension fork received from the manufacturer.
Note 3: Stemme Service Bulletin No. A31-10-051, Amendment 01.a,
pages 3 and 4, dated March 6, 1999, pertains to the subject matter
of this AD.
(b) 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.
(c) An alternative method of compliance or adjustment of the
initial or repetitive 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 4: 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. A31-10-051, Amendment 01.a, dated March 6, 1999, should
be directed to 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 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 5: The subject of this AD is addressed in German AD 1999-
224, dated June 4, 1999.
Issued in Kansas City, Missouri, on July 14, 1999.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-18630 Filed 7-20-99; 8:45 am]
BILLING CODE 4910-13-U
