[Federal Register Volume 86, Number 201 (Thursday, October 21, 2021)]
[Proposed Rules]
[Pages 58228-58230]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-22680]



[[Page 58228]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0878; Project Identifier MCAI-2020-01460-G]
RIN 2120-AA64


Airworthiness Directives; Schempp-Hirth Flugzeugbau GmbH Gliders

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Schempp-Hirth Flugzeugbau GmbH Model Duo Discus and Duo 
Discus T gliders. This proposed AD was prompted by 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 jerky 
extension of the air brakes at very high air speeds, including cases 
where the air brake blades interlock. This proposed AD would require 
replacing certain air brake end stop bushings, inspecting certain other 
air brake end stops, and repairing 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 6, 
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 Schempp-
Hirth Flugzeugbau GmbH, Krebenstrasse 25, 73230 Kirchheim/Teck, 
Germany; phone: +49 7021 7298-0; fax: +49 7021 7298-199; email: 
hirth.com">[email protected]hirth.com; website: https://www.schempp-hirth.com. You may 
view this referenced 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-2021-0878; 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: 
[email protected].

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-2021-0878; Project Identifier 
MCAI-2020-01460-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 2020-0233, dated October 27, 2020 (referred to after this as 
``the MCAI''), to address an unsafe condition on certain serial-
numbered (S/N) Schempp-Hirth Flugzeugbau GmbH Model Duo Discus, Duo 
Discus C, and Duo Discus T gliders. The MCAI states:

    Occurrences were reported of experiencing jerky extension of the 
airbrakes at very high air speeds, in some cases of which the 
airbrake blades interlocked. An increasing number of age-related 
damage was observed on a specific version (22 mm plastic bushes) of 
the airbrake end-stops.
    This condition, if not corrected, could lead to blockage of the 
airbrakes, possibly resulting in reduced control of the (powered) 
sailplane.
    To address this potential unsafe condition, Schempp-Hirth issued 
the applicable [technical note] TN (original issue) to provide 
instructions to replace the affected parts with a new version 
bushing, made of better material.
    Since [EASA planned AD] PAD 20-119 was issued, it was discovered 
that early s/n sailplanes were equipped with a single metal end stop 
per airbrake. The applicable TN was revised accordingly. The PAD was 
revised to include those metal end stops in the definition of 
`affected part' to ensure these are inspected.
    For the reasons described above, this [EASA] AD requires 
replacement of certain affected parts with serviceable parts. For 
other affected parts, this [EASA] AD requires a one-time inspection 
for sufficient overlap and, depending on findings, accomplishment of 
applicable corrective action(s). This [EASA] AD also prohibits 
(re)installation of affected parts.

    You may examine the MCAI in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-
0878.

[[Page 58229]]

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Schempp-Hirth Flugzeugbau GmbH Working 
Instructions for Technical Note 890-16 rev1 and Technical Note 396-20 
rev1 action 1, dated September 18, 2020. The service information 
contains procedures for replacing each air brake end stop plastic 
bushing (22 mm) with an air brake end stop plastic bushing (32 mm). The 
FAA also reviewed Schempp-Hirth Flugzeugbau GmbH Working Instructions 
for Technical Note 396-20 rev1 action 2, dated September 18, 2020. The 
service information contains procedures for inspecting each single air 
brake metal end stop for overlap. 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.

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 the unsafe condition described previously is likely 
to exist or develop on other products of the same type design.

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information already described, except as described under 
``Differences Between this Proposed AD and the MCAI.'' This proposed AD 
would also require repairing any single air brake metal end stop with 
insufficient overlap.

Differences Between This Proposed AD and the MCAI

    The MCAI applies to Schempp-Hirth Flugzeugbau GmbH Model Duo Discus 
C gliders, and this proposed AD would not because this model does not 
have an FAA type certificate.
    The MCAI allows credit for modifications done prior to the 
effective date of the EASA AD in accordance with the original issue of 
Schempp-Hirth TN 396-20/TN 890-16, but this proposed AD would not 
provide such credit.
    The MCAI prohibits installation of air brake end stop plastic 
bushings (22 mm) after a glider has been modified with an air brake end 
stop plastic bushing (32 mm). This proposed AD would prohibit 
installation of air brake end stop plastic bushings (22 mm) as of the 
effective date of this AD.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 27 gliders of U.S. registry.
    The FAA estimates the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                              Cost per          Cost on U.S.
              Action                      Labor cost         Parts cost        product           operators
----------------------------------------------------------------------------------------------------------------
Replace plastic end stop bushings.  4 work-hours x $85               $150            $490  Up to $13,230
                                     per hour = $340.                                       (depending on number
                                                                                            of gliders with
                                                                                            plastic end stop
                                                                                            bushings).
Inspect metal end stops...........  1 work-hour x $85 per               0              85  Up to $2,295
                                     hour = $85.                                            (depending on number
                                                                                            of gliders with
                                                                                            metal end stops).
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary repairs 
that would be required based on the results of the proposed inspection. 
The FAA has no way of determining the number of gliders that might need 
these repairs:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Repair metal end stops.......................  4 work-hours x $85 per hour =              $150             $490
                                                $340.
----------------------------------------------------------------------------------------------------------------

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.

[[Page 58230]]

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

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

Schempp-Hirth Flugzeugbau GmbH: Docket No. FAA-2021-0878; Project 
Identifier MCAI-2020-01460-G.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by December 6, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to the Schempp-Hirth Flugzeugbau GmbH gliders 
identified in paragraphs (c)(1) and (2) of this AD, certificated in 
any category.
    (1) Model Duo Discus gliders, serial number (S/N) 1 through 541 
inclusive, except S/N 534.
    (2) Model Duo Discus T gliders, S/N 1 through 174 inclusive.

(d) Subject

    Joint Aircraft System Component (JASC) Code 2760, Drag Control 
System.

(e) Unsafe Condition

    This AD was prompted by 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 jerky extension 
of the air brakes at very high air speeds, including cases where the 
air brake blades interlock. The FAA is issuing this AD to prevent 
and correct damage of the airbrake end-stops. The unsafe condition, 
if not addressed, could result in blockage of the air brakes and 
reduced control of the glider.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) For gliders with air brake end stop plastic bushings (22 mm) 
installed: Within 3 months after the effective date of this AD, 
replace each air brake end stop plastic bushing (22 mm) with an air 
brake end stop plastic bushing (32 mm) in accordance with Schempp-
Hirth Flugzeugbau GmbH Working Instructions for Technical Note 890-
16 rev1 and Technical Note 396-20 rev1 action 1, dated September 18, 
2020.
    (2) For gliders with single air brake metal end stops installed: 
Within 3 months after the effective date of this AD, inspect each 
single air brake metal end stop for overlap in accordance with 
Schempp-Hirth Flugzeugbau GmbH Working Instructions for Technical 
Note 396-20 rev1 action 2, dated September 18, 2020. If there is 
insufficient overlap, before further flight, repair using a method 
approved by the FAA or the European Union Aviation Safety Agency 
(EASA).

(h) Parts Installation Prohibition

    As of the effective date of this AD, do not install an air brake 
end stop plastic bushing (22 mm) on any glider.

(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 International Validation Branch, send 
it to the attention of the person identified in paragraph (j)(1) of 
this AD or email: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, 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: 
[email protected].
    (2) Refer to EASA AD 2020-0233, dated October 27, 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-2021-0878.
    (3) For service information identified in this AD, contact 
Schempp-Hirth Flugzeugbau GmbH, Krebenstrasse 25, 73230 Kirchheim/
Teck, Germany; phone: +49 7021 7298-0; fax: +49 7021 7298-199; 
email: hirth.com">[email protected]hirth.com; website: https://www.schempp-
hirth.com. You may view this referenced 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.

    Issued on October 8, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-22680 Filed 10-20-21; 8:45 am]
BILLING CODE 4910-13-P


