DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-1421; Project Identifier MCAI-2022-01088-G]
RIN 2120-AA64

Airworthiness Directives; Stemme AG Gliders

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2022-01-09, which applies to certain Stemme AG Model Stemme S 10-VT and
Model Stemme S 12 gliders. AD 2022-01-09 requires removing the affected
freewheel clutch from service and prohibits the installation of
affected parts. Since the FAA issued AD 2022-01-09, the European Union
Aviation Safety Agency (EASA) superseded its mandatory continuing
airworthiness information (MCAI) to amend the definition of an affected
part. This proposed AD would retain the requirements of AD 2022-01-09
for removing the affected freewheel clutch from service and continue to
prohibit the installation of an affected part, and would amend the
definition of an affected part and clarify the part installation
prohibition. The FAA is proposing this AD to address the unsafe
condition on these products.

DATES: The FAA must receive comments on this NPRM by January 3, 2023.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to 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: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2022-1421; or in person at Docket Operations between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD
docket contains this NPRM, the MCAI, any comments received, and other
information. The street address for Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Jim Rutherford, Aviation Safety
Engineer, General Aviation & Rotorcraft Section, International
Validation Branch, FAA, 901 Locust, Room 301, Kansas City, MO 64106;
phone: (816) 329-4165; email: jim.rutherford@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2022-1421; Project Identifier
MCAI-2022-01088-G'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
the proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this NPRM.

Confidential Business Information

CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to Jim
Rutherford, Aviation Safety Engineer, General Aviation & Rotorcraft
Section, International Validation Branch, FAA, 901 Locust, Room 301,
Kansas City, MO 64106. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.

Background

The FAA issued AD 2022-01-09, Amendment 39-21897 (87 FR 1666,
January 12, 2022) (AD 2022-01-09), for all Stemme AG Model Stemme S 10-
VT and Model Stemme S 12 gliders with a freewheel clutch part number
(P/N) 12AK with a serial number starting with ``12-'' installed. AD
2022-01-09 was prompted by MCAI originated by EASA, which is the
Technical Agent for the Member States of the European Union. EASA
issued EASA Emergency AD 2021-0278-E, dated December 15, 2021 (EASA AD
2021-0278-E), to correct an unsafe condition identified as unintended
slipping of the freewheel clutch with overheating (burnishing) of the
friction pads inside of the clutch.
AD 2022-01-09 requires removing the affected freewheel clutch from
service and prohibits installing an affected part on any glider. The
FAA issued AD 2022-01-09 to address unintended slipping of the
freewheel clutch with overheating (burnishing) of the friction pads
inside of the clutch, which if not addressed, could result in a loss of
thrust and consequent loss of glider control.

Actions Since AD 2022-01-09 Was Issued

Since the FAA issued AD 2022-01-09, EASA superseded EASA AD 2021-
0278-E and issued EASA AD 2021-0278R1, dated August 11, 2022 (referred
to after this as ``the MCAI''), to correct an unsafe condition on all
Stemme AG Model Stemme S 10-VT and Stemme S 12 gliders. The MCAI states
that the definition of affected part was amended to exclude certain
modified and re-identified freewheel clutches.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2022-1421.

FAA's Determination

These products have been approved by the aviation authority of
another country and are approved for operation in the United States.
Pursuant to the FAA's bilateral agreement with this State of Design
Authority, it has notified the FAA of the unsafe condition described in
the MCAI and service information described above. The FAA is issuing
this NPRM after determining that the unsafe condition described
previously is likely to exist or develop on other products of these
same type designs.

Proposed AD Requirements in this NPRM

This proposed AD would retain the requirements of AD 2022-01-09 for
removing the affected freewheel clutch from service and continue to
prohibit the installation of an affected part, and would amend the
definition of an affected part and clarify the part installation
prohibition.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 63 gliders of U.S. registry.
The FAA estimates the following costs to comply with this proposed
AD:

Estimated Costs

The new requirements of this proposed AD add no additional economic
burden over that already required by AD 2022-01-09.

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.
The FAA is 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.

Regulatory Findings

The FAA 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 that the proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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:

a. Removing Airworthiness Directive 2022-01-09, Amendment 39-21897 (87
FR 1666, January 12, 2022); and

b. Adding the following new airworthiness directive: