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PROPOSED AD FIBERGLAS-TECHNIK RUDOLF LINDNER GMBH & CO. KG (TYPE CERTIFICATE PREVIOUSLY HELD BY GROB AIRCRAFT AG, GROB AEROSPACE GMBH I.L., GROB AEROSPACE GMBH, BURKHART GROB LUFT-UND RAUMFAHRT GMBH & CO. KG): Docket No. FAA-2021-0944; Project Identifier MCAI-2020-00800-G.
(a) COMMENTS DUE DATE

    The FAA must receive comments on this airworthiness directive (AD)  by
    December 13, 2021.

(b) AFFECTED ADS

    None.

(c) APPLICABILITY

    This AD applies to the following gliders, all serial numbers, certifi-
    cated in any category:

(1) Fiberglas-Technik Rudolf Lindner GmbH & Co. KG  (type certificate pre-
    viously held by GROB Aircraft AG, Grob Aerospace GmbH i.l., Grob Aero-
    space GmbH, Burkhart Grob Luft-und Raumfahrt GmbH & Co. KG,  GROB TFE,
    GROB-WERKE GMBH & CO KG  (a  division  of  Burkhart Grob Flugzeugbau))
    Model G102 ASTIR CS.

(2) Fiberglas-Technik Rudolf Lindner GmbH & Co. KG  (type certificate pre-
    viously held by GROB Aircraft AG, Grob Aerospace GmbH i.l., Grob Aero-
    space GmbH,  Burkhart  Grob  Luft-und Raumfahrt GmbH & Co. KG))  Model
    G103 TWIN ASTIR,  G103 TWIN II,  G103A TWIN II ACRO,  G103 C  TWIN III
    ACRO, and G 103 C TWIN III SL.

(d) SUBJECT

    Joint Aircraft System Component (JASC) Code 2730, Elevator Control Sys
    -tem.

(e) UNSAFE CONDITION

    This AD was prompted by mandatory continuing airworthiness information
    (MCAI) issued by the aviation authority of another country to identify
    and  correct an  unsafe condition  on an  aviation product.  The  MCAI
    describes the unsafe  condition as corrosion  on the elevator  control
    pushrod.  The  unsafe condition,  if  not addressed,  could  result in
    failure of  the elevator  control pushrod  and loss  of control of the
    glider.

(f) COMPLIANCE

    Comply with this AD within the compliance times specified,  unless al-
    ready done.

(g) REQUIRED ACTIONS

(1) Within 25 hours time in service (TIS) after the effective date of this
    AD, inspect the elevator control pushrod in the vertical fin for water
    and corrosion, and replace the elevator control pushrod before further
    flight  if there  is any  water or  corrosion in  accordance with  the
    Actions  and Instructions,  paragraph 3,  of Fiberglas-Technik  Rudolf
    Lindner Anweisung/Instructions  (A/I-G09), Revision  1, dated  May 14,
    2020.

(2) If no water and no corrosion is detected, before further flight, treat
    the inside of the elevator control pushrod with corrosion preventative
    LPS 3 or equivalent.

(3) If required by paragraph (g)(1) of this AD,  you must replace the ele-
    vator control pushrod before  further flight with an  elevator control
    pushrod that has  zero hours TIS  or with an  elevator control pushrod
    that has passed  the inspection in  accordance with paragraphs  (g)(1)
    and (2) of this AD.

(h) CREDIT FOR PREVIOUS ACTIONS

    You may take credit for the actions required  by paragraphs (g)(1) and
    (2) of this AD if you performed  these  actions  before  the effective
    date  of  this  AD  using  Fiberglas-Technik Rudolf Lindner Anweisung/
    Instructions (A/I-G09), dated April 8, 2020.

(i) ALTERNATIVE METHODS OF COMPLIANCE (AMOCS)

(1) The Manager, International Validation Branch,  FAA,  has the authority
    to approve AMOCs for this AD, if requested using the procedures  found
    in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to
    your principal inspector or local Flight Standards District Office, as
    appropriate. If  sending information  directly to  the manager  of the
    certification  office,  send  it  to  the  attention  of  the   person
    identified in paragraph (j)(1) of this AD or email: 9-AVS-AIR-730-AMOC
    @faa.gov.

(2) Before using any approved AMOC,  notify your appropriate principal in-
    spector, or lacking  a principal inspector,  the manager of  the local
    flight standards district office/certificate holding district office.

(j) RELATED INFORMATION

(1) For more information about this AD,  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; fax: (816) 329-4090; email: jim.rutherford@faa.
    gov.

(2) Refer  to  European Union Aviation Safety Agency (EASA)  AD 2020-0138,
    dated June 19, 2020, for more information. You may examine the EASA AD
    in the AD docket  at https://www.regulations.gov by searching  for and
    locating it in Docket No. FAA-2021-0944.

(3) For service information identified in this AD, contact Fiberglas-Tech-
    nik Rudolf Lindner GmbH & Co. KG,  Steige  3,  D-88487  Walpertshofen,
    Germany;  phone: +49 (0) 7353 22 43;  email: info@LTB-Lindner.com; web
    site: https://www.ltb-lindner.com.  You may view this referenced serv-
    ice information at the FAA, Airworthiness Products Section, Operation-
    al Safety Branch, 901 Locust, Kansas City, MO 64106.  For  information
    on the availability of this material at the FAA, call (816) 329-4148.

Issued on October 21, 2021. Lance T Gant, Director, Compliance & Airworth-
iness Division, Aircraft Certification Service.

DATES: The FAA must receive comments  on this proposed AD  by December 13,
2021.
PREAMBLE 

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0944; Project Identifier MCAI-2020-00800-G]
RIN 2120-AA64

Airworthiness Directives
; Fiberglas-Technik Rudolf Lindner GmbH &
Co. KG (Type Certificate Previously Held by GROB Aircraft AG, Grob
Aerospace GmbH i.l., Grob Aerospace GmbH, Burkhart Grob Luft-und
Raumfahrt GmbH & Co. KG) Gliders

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for all Fiberglas-Technik Rudolf Lindner GmbH & Co. KG (type
certificate previously held by GROB Aircraft AG, Grob Aerospace GmbH
i.l., Grob Aerospace GmbH, Burkhart Grob Luft-und Raumfahrt GmbH & Co.
KG) Model G102 ASTIR CS, G103 TWIN ASTIR, G103 TWIN II, G103A TWIN II
ACRO, G103C TWIN III ACRO, and G 103 C TWIN III SL gliders. This
proposed AD was prompted by mandatory continuing airworthiness
information (MCAI) issued by the aviation authority of another country
to identify and correct an unsafe condition on an aviation product. The
MCAI describes the unsafe condition as corrosion on the elevator
control pushrod. This proposed AD would require inspecting the elevator
control pushrod for water and corrosion and replacing the pushrod if
necessary. The FAA is proposing this AD to address the unsafe condition
on these products.

DATES: The FAA must receive comments on this proposed AD by December
13, 2021.

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 https://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: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
For service information identified in this NPRM, contact Fiberglas-
Technik Rudolf Lindner GmbH & Co. KG, Steige 3, D-88487 Walpertshofen,
Germany; phone: +49 (0) 7353 22 43; email: info@LTB-Lindner.com;
website: https://www.ltb-lindner.com. You may view this service
information at the FAA, Airworthiness Products Section, Operational
Safety Branch, 901 Locust, Kansas City, MO 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 at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0944; 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; fax: (816) 329-4090; 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-2021-0944; Project Identifier
MCAI-2020-00800-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
this 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
https://www.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, FAA, 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 European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Union, has issued
EASA AD 2020-0138, dated June 19, 2020 (referred to after this as ``the
MCAI''), to address an unsafe condition on Fiberglas-Technik R. Lindner
GmbH & Co. KG Model ASTIR CS, ASTIR CS 77, ASTIR CS Jeans, CLUB ASTIR
II, STANDARD ASTIR II, TWIN ASTIR, TWIN ASTIR TRAINER, GROB G 103
``TWIN II,'' GROB G 103 A ``TWIN II ACRO,'' GROB G 103 C ``TWIN III,''
GROB G 103 C ``TWIN III ACRO,'' GROB G 103 C TWIN III SL, ASTIR CS 77
TOP, ASTIR CS JEANS TOP, and ASTIR CS TOP gliders. The MCAI states:

During a routine inspection, a severely corroded elevator
control pushrod was found in the vertical fin on a Grob TWIN ASTIR
sailplane. The technical investigation results revealed that water
had soaked into the elevator control pushrod, causing the corrosion
damage and subsequent considerable weakening of the steel tube
pushrod.
This condition, if not detected and corrected, could lead to
failure of the elevator control pushrod, possibly resulting in loss
of control of the sailplane.
To address this unsafe condition, Fiberglas-Technik R. Lindner
GmbH & Co.KG published the [technische mitteilung/service bulletin]
TM/SB and [anweisung/instructions] A/I-G09, at original issue,
providing instructions for elevator control pushrod inspection and
replacement. Prompted by this development, EASA issued AD 2020-0121
to require a one-time inspection of the elevator control pushrod in
the vertical fin and, depending on findings, replacement.
After EASA AD 2020-0121 was issued, it was determined that Grob
G 103 ``TWIN II'' sailplanes, and additional Grob G 103 A ``TWIN II
ACRO'' sailplanes, are also prone to elevator control pushrod
corrosion and Fiberglas-Technik R.Lindner GmbH & Co.KG issued the
TM/SB to make the inspection instructions applicable to these
sailplane models.
For the reasons described above, this [EASA] AD retains the
requirements of EASA AD 2020-0121, which is superseded, and expands
the Applicability.

You may examine the MCAI in the AD docket at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-0944.

FAA's Determination

This product has been approved by the aviation authority of another
country and is 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 referenced 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 the same type design.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Fiberglas-Technik Rudolf Lindner Anweisung/
Instructions (A/I-G09), Revision 1, dated May 14, 2020. This service
information provides instructions to inspect the elevator control
pushrod for water and corrosion, replace the elevator control pushrod
if any water or corrosion is found, and apply corrosion prevention if
no water and no corrosion are found. 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
ADDRESSES.

Other Related Service Information

The FAA also reviewed Fiberglas-Technik Rudolf Lindner Service
Bulletin (SB-G09), Revision 1, dated May 14, 2020. This service
information refers to the instructions in A/I-G09 to inspect and
replace the elevator control pushrod on various gliders.
The FAA reviewed Grob TFE Service Bulletin TM 315-34, dated
December 8, 1987. This service information provides effectivity,
reason, and high-level instructions for inspecting and replacing the
elevator control pushrod on certain Model G 103 A TWIN II ACRO gliders.
The FAA reviewed Grob TFE Repair Instructions No. 315-34 for
Service Bulletin TM 315-34, dated December 8, 1987. This service
information provides more detailed instructions for inspecting and
replacing the elevator control pushrod on certain Model G 103 A TWIN II
ACRO gliders.

Proposed AD Requirements

This proposed AD would require inspecting the elevator control
pushrod and replacing it if water or corrosion are found.

Differences Between This Proposed AD and the MCAI

The MCAI applies to Model ASTIR CS 77, ASTIR CS Jeans, CLUB ASTIR
II, STANDARD ASTIR II, TWIN ASTIR TRAINER, GROB G 103 C ``TWIN III,''
ASTIR CS 77 TOP, ASTIR CS JEANS TOP, and ASTIR CS TOP gliders. This
proposed AD would not apply to these model gliders because they do not
have an FAA type certificate.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 149 gliders of U.S. registry. The FAA estimates that it would
take about 4 work-hours per glider to inspect the elevator control
pushrod and require parts costing $100. The average labor rate is $85
per work-hour. Based on these figures, the FAA estimates the cost to
inspect the elevator control pushrod on U.S. operators to be $65,560 or
$440 per glider.
In addition, the FAA estimates that for gliders with water or
corrosion within the elevator control pushrod, replacement would take
about 8 work-hours and require parts costing $500. The average labor
rate is $85 per work-hour. Based on these figures, the FAA estimates
the replacement of this proposed AD to be $1,180 per glider.

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 this 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 adding the following new airworthiness
directive: