DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0911; Product Identifier 2017-CE-025-AD]
RIN 2120-AA64

Airworthiness Directives; Alexander Schleicher GmbH & Co.
Segelflugzeugbau Gliders

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all
Alexander Schleicher GmbH & Co. Segelflugzeugbau Models ASH 25M and ASH
26E gliders. This proposed AD results from mandatory continuing
airworthiness information (MCAI) originated by an aviation authority of
another country to identify and correct an unsafe condition on an
aviation product. The MCAI describes the unsafe condition as fatigue
cracks found on the exhaust silencer. We are issuing this proposed AD
to require actions to address the unsafe condition on these products.

DATES: We must receive comments on this proposed AD by November 6,
2017.

ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the
instructions for submitting comments.
Fax: (202) 493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE., Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
For service information identified in this proposed AD, contact
Alexander Schleicher GmbH & Co. Segelflugzeugbau, Alexander-Schleicher-
Str. 1, D-36163 Poppenhausen, Germany; phone: +49 (0) 06658 89-0; fax:
+49 (0) 06658 89-40; Internet: http://www.alexander-schleicher.de/;
email: info@alexander-schleicher.de. You may review this referenced
service information at the FAA, Policy and Innovation Division, 901
Locust, Kansas City, Missouri 64106. For information on the availability of this
material at the FAA, call (816) 329-4148.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.
gov by searching for and locating Docket No. FAA-2017-
0911; or in person at the Docket Management Facility between 9 a.m. and
5 p.m., Monday through Friday, except Federal holidays. The AD docket
contains this proposed AD, the regulatory evaluation, any comments
received, and other information. The street address for the Docket
Office (telephone (800) 647-5527) is in the ADDRESSES section. Comments
will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Jim Rutherford, Aerospace Engineer,
FAA, Small Airplane Standards Branch, 901 Locust, Room 301, Kansas
City, Missouri 64106; telephone: (816) 329-4165; fax: (816) 329-4090;
email: jim.rutherford@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2017-0911;
Product Identifier 2017-CE-025-AD'' at the beginning of your comments.
We specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this proposed AD. We will consider
all comments received by the closing date and may amend this proposed
AD because of those comments.
We will post all comments we receive, without change, to http://regulations.
gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.

Discussion

The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Community, has issued AD
No. 2017-0136, dated July 31, 2017 (referred to after this as ``the
MCAI''), to correct an unsafe condition for the specified products. The
MCAI states:

Occurrences were reported of finding cracks on exhaust silencer
part number (P/N) 800.65.0001, installed on ASK 21 Mi powered
sailplanes. Subsequent investigation determined that the affected
part is susceptible to fatigue cracking and is also installed on
other Schleicher powered sailplanes.
This condition, if not corrected, could lead to heat damage in
the engine compartment and to the engine installation, possibly
resulting in reduced control of the powered sailplane.
To address this potentially unsafe condition, Schleicher issued
Technical Note (TN) ASK 21 Mi No. 11, TN ASW 22 BLE 50R No. 16, TN
ASH 25 M/Mi No. 32 and TN ASH 26 E No. 19 (single document,
hereafter referred to as `the TN' in this [EASA] AD), to provide
replacement instructions.
For the reasons described above, this [EASA] AD requires
replacement of the affected exhaust silencer with an improved part
and introduces installation restrictions of a part with P/N
800.65.0001.

You may examine the MCAI on the Internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2017-0911.

Related Service Information Under 1 CFR Part 51

Alexander Schleicher GmbH & Co. Segelflugzeugbau has issued ASK 21
Mi Technical Note No. 11, ASW 22 BLE 50R Technical Note No. 16, ASH 25
M/Mi Technical Note No. 32, ASH 26 E Technical Note No. 19 (single
document), dated January 8, 2016. The service information describes
procedures for replacing the exhaust silencer with an improved part.
This service information is reasonably available because the interested
parties have access to it through their normal course of business or by
the means identified in the ADDRESSES section of this NPRM.

FAA's Determination and Requirements of the Proposed AD

This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to our bilateral agreement with this State of Design Authority, they
have notified us of the unsafe condition described in the MCAI and
service information referenced above. We are proposing this AD because
we evaluated all information and determined the unsafe condition exists
and is likely to exist or develop on other products of the same type
design.

Costs of Compliance

We estimate that this proposed AD will affect 35 products of U.S.
registry. We also estimate that it would take about 8 work-hours per
product to comply with the basic requirements of this proposed AD. The
average labor rate is $85 per work-hour. Required parts would cost
about $3,900 per product.
Based on these figures, we estimate the cost of this proposed AD on
U.S. operators to be $160,300, or $4,580 per product.
We have no way of determining the number of products that have an
affected exhaust silencer, part number 800.65.0001, installed that
would need to be replaced. Therefore, this cost estimate includes all
affected gliders on the U.S. registry.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. ``Subtitle VII: Aviation
Programs,'' describes in more detail the scope of the Agency's
authority.
We are issuing this rulemaking under the authority described in
``Subtitle VII, Part A, Subpart III, section 44701: General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
This AD is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to small airplanes, gliders, and
domestic business jet transport airplanes to the Director of the Policy
and Innovation Division.

Regulatory Findings

We determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would not
have a substantial direct effect 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.
For the reasons discussed above, I certify this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Is not a ``significant rule'' under the DOT Regulatory Policies
and
Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) 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.

List of Subjects in 14 CFR Part 39

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

The Proposed Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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. The FAA amends Sec. 39.13 by adding the following new AD: