[Federal Register Volume 86, Number 228 (Wednesday, December 1, 2021)]
[Proposed Rules]
[Pages 68168-68171]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-26042]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-1015; Project Identifier 2019-CE-014-AD]
RIN 2120-AA64


Airworthiness Directives; DG Flugzeugbau GmbH and 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 DG Flugzeugbau GmbH Model DG-1000T gliders and Schempp-Hirth 
Flugzeugbau GmbH Model Duo Discus T gliders with a Solo Kleinmotoren 
GmbH Solo Model 2350C or 2350D engine installed. 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 failure of the bearing of the upper pulley of 
the belt driven reduction gear resulting in separation of the propeller 
from the engine. This proposed AD would require replacing a certain 
hex-nut and would establish a lift limit for the ball bearing assembly. 
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 January 18, 
2022.

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.

[[Page 68169]]

     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 Solo 
Kleinmotoren GmbH, Postfach 600152, D71050 Sindelfingen, Germany; 
phone: +49 703 1301-0; fax: +49 703 1301-136; email: germany.com">aircraft@solo-germany.com; website: http://aircraft.solo-online.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-2021-1015; 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-2021-1015; Project Identifier 
2019-CE-014-AD'' 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 Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Union, has issued EASA AD 
2019-0029, dated February 8, 2019 (referred to after this as ``the 
MCAI''), to address an unsafe condition on Solo Kleinmotoren GmbH Solo 
Model 2350B, 2350BS, 2350C, and 2350D engines. The MCAI states:

    An occurrence was reported of failure of the bearing of the 
upper pulley of the belt driven reduction gear, resulting in 
separation of the propeller from the engine.
    This condition, if not corrected, could lead to similar 
occurrences, with possible reduced control of, and damage to, the 
aircraft.
    To address this potential unsafe condition, Solo redesigned the 
nut securing the pulley bearing on the axle and introduced a life 
time limit of 15 years for the reduction gear bearings.
    For the reason stated above, this [EASA] AD requires replacement 
of affected parts with serviceable parts, and introduces a life 
limit for the affected ball bearings.

    You may examine the MCAI in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-
1015.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Solo Kleinmotoren GmbH Service Bulletin 4603-18, 
dated January 22, 2019. The service information contains procedures for 
replacing the hex-nut at the excentric axle and the ball bearing 
assemblies at the bearing block of the reduction gear. 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.

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 in This NPRM

    This proposed AD would require removing the affected hex-nut from 
service and replacing it with a flange-nut. This proposed AD would also 
establish a lift limit of 15 years for the affected ball bearing 
assemblies.

Differences Between This Proposed AD and the MCAI or Service 
Information

    The MCAI applies to Solo Kleinmotoren GmbH Solo Model 2350B, 
2350BS, 2350C, and 2350D engines. None of these model engines have an 
FAA engine type certificate. However, Model 2350C and Model 2350D 
engines are certificated by the FAA with the type certificate for 
certain gliders. This proposed AD would not apply to Solo Kleinmotoren 
GmbH Solo Model 2350B and 2350BS engines because they are not part of 
an FAA glider type design.
    The MCAI requires replacing an affected ball bearing assembly 
before it accumulates 15 years since first installation on an engine. 
This proposed AD would require replacing both ball bearing assemblies 
simultaneously before either accumulates 15 years since first 
installation on an engine.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 10 gliders of U.S. registry. The FAA estimates that for gliders 
with an affected hex-nut, replacement would take about 0.5 work-hour 
and require a

[[Page 68170]]

part costing $95. The average labor rate is $85 per work-hour. Based on 
these figures, the FAA estimates the cost to replace the hex-nut on 
U.S. operators to be $1,380 (assuming all 10 gliders have this 
configuration) or $138 per glider.
    In addition, the FAA estimates that for gliders with the affected 
ball bearing assemblies, replacement would take about 4 work-hours for 
both ball bearing assemblies and require ball bearing assemblies 
costing $118 (2 units). The average labor rate is $85 per work-hour. 
Based on these figures, the FAA estimates the cost of the ball bearing 
assembly replacement on U.S. operators to be $4,580 (assuming all 10 
gliders have this configuration) or $458 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

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:

DG Flugzeugbau GmbH and Schempp-Hirth Flugzeugbau GmbH Gliders: 
Docket No. FAA-2021-1015; Project Identifier 2019-CE-014-AD.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by January 18, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to DG Flugzeugbau GmbH Model DG-1000T gliders 
and Schempp-Hirth Flugzeugbau GmbH Model Duo Discus T gliders, 
certificated in any category, with a Solo Kleinmotoren GmbH Solo 
Model 2350C or 2350D engine, all serial numbers, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7200, Engine 
(Turbine/Turboprop).

(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 failure of the 
bearing of the upper pulley of the belt driven reduction gear. The 
FAA is issuing this AD to prevent separation of the propeller from 
the engine. The unsafe condition, if not addressed, could result in 
loss of control of the aircraft.

(f) Compliance

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

(g) Actions and Compliance

    (1) Within 12 months after the effective date of this AD, remove 
the nut installed at the excentric axle from service and replace it 
with a nut in accordance with the Condition section, paragraph a, of 
Solo Kleinmotoren GmbH Service Bulletin 4603-18, dated January 22, 
2019.
    (2) Before either ball bearing assembly at the bearing block of 
the reduction gear accumulates 15 years since first installation on 
an engine or within 12 months after the effective date of this AD, 
whichever occurs later, and thereafter at intervals not to exceed 15 
years, remove both ball bearing assemblies from service and replace 
with new (zero hours time-in-service) ball bearing assemblies in 
accordance with the Condition section, paragraph b, of Solo 
Kleinmotoren GmbH Service Bulletin 4603-18, dated January 22, 2019.
    (3) After replacing the ball bearing assemblies required by 
paragraph (g)(2) of this AD, record compliance in the aircraft log 
book. The entry must include: (1) Reduction gear part number (P/N) 
and serial number; and (2) date ball bearing assemblies were 
replaced.
    (4) As of the effective date of this AD, do not install a hex-
nut P/N 0028143 on any engine.
    (5) As of the effective date of this AD, do not install ball 
bearing assembly P/N 0050110 on any engine unless it is new (zero 
hours time-in-service).

(h) 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 (i)(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.

(i) 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 European Aviation Safety Agency (EASA) AD 2019-
0029, dated February 8, 2019, 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-2021-1015.
    (3) For service information identified in this AD, contact Solo 
Kleinmotoren GmbH, Postfach 600152, D71050 Sindelfingen, Germany; 
phone: +49 703 1301-0; fax: +49 703 1301-136; email: germany.com">aircraft@solo-germany.com; website: http://aircraft.solo-online.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.


[[Page 68171]]


    Issued on November 19, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-26042 Filed 11-30-21; 8:45 am]
BILLING CODE 4910-13-P