Document ID: FAA-2021-0716-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Stemme AG Gliders
Posted Date: 2021-08-27T04:00Z

[Federal Register Volume 86, Number 164 (Friday, August 27, 2021)]
[Proposed Rules]
[Pages 48065-48067]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-18387]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0716; Project Identifier 2019-CE-023-AD]
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 adopt a new airworthiness directive (AD) 
for all Stemme AG Model Stemme S 12 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 an airspeed indicator (ASI) with speed markings 
inconsistent with the approved and published values. This proposed AD 
would require inspecting the ASI markings and, depending on findings, 
either replacing the ASI or amending the existing aircraft flight 
manual (AFM) until the ASI is replaced. 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 October 12, 
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 STEMME AG, 
Flugplatzstrasse F2, Nr. 6-7, D-15344 Strausberg, Germany; phone: +49 
(0) 3341 3612-0, fax: +49 (0) 3341 3612-30; email: 
airworthiness@stemme.de; website: https://www.stemme.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-2021-0716; 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-2021-0716; Project Identifier 
2019-CE-023-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

[[Page 48066]]

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 European Union Aviation Safety Agency (EASA), which is the 
Technical Agent for the Member States of the European Union, has issued 
EASA AD 2019-0082, dated April 12, 2019 (referred to after this as 
``the MCAI''), to address an unsafe condition on Stemme AG Model Stemme 
S 12 gliders. The MCAI states:

    During a production inspection of a new powered sailplane, an 
ASI was found with speed markings inconsistent with the approved and 
published values (begin[ning] of the white and green arc). 
Subsequent investigation of the production records for delivered 
Stemme S 12 powered sailplanes does not exclude that a similar, non-
conforming ASI was installed during production.
    This condition, if not corrected, could lead to erroneous 
information being provided to the pilot, particularly at the lower 
speed operation limits, possibly resulting in reduced control of the 
powered sailplane.
    To address this unsafe condition, Stemme AG issued the SB 
[service bulletin] to provide inspections instructions.
    For the reason described above, this [EASA] AD requires a one-
time inspection of the markings of the affected part and, depending 
on findings, amending the Aircraft Flight Manual (AFM) and replacing 
the affected part. This [EASA] AD also prohibits 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-
0716.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Stemme Service Bulletin No. P062-980027, Revision 
00, dated December 17, 2018. The service information specifies checking 
the ASI markings and provides illustrations of correct markings. The 
service information specifies the procedure to replace an affected ASI 
with an ASI with correct markings. The service information also 
includes a temporary page to insert into the AFM until the ASI is 
replaced. 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 a one-time inspection of the ASI 
markings and, depending on findings, either replacing the ASI before 
further flight or amending the existing AFM until the ASI is replaced 
within 3 months.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 20 gliders of U.S. registry. The FAA estimates that it would 
take about 0.5 work-hour per glider to comply with the inspection 
requirements of this AD. The average labor rate is $85 per work-hour.
    Based on these figures, the FAA estimates the cost of this AD on 
U.S. operators to be $850 or $42.50 per glider.
    The FAA estimates that amending the AFM to insert and then remove 
the temporary page as a result of the inspection would take about 1 
work-hour per glider for a total cost of $85 per glider. The FAA 
estimates that replacing the ASI would take about 3.5 work-hours and 
require parts costing $603, for a total cost of $900.50 per glider. The 
FAA has no way of determining the number of gliders that may need these 
actions.
    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this AD 
may be covered under warranty, thereby reducing the cost impact on 
affected operators.

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:

Stemme AG: Docket No. FAA-2021-0716; Project Identifier 2019-CE-023-
AD.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by October 12, 2021.

[[Page 48067]]

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Stemme AG Model Stemme S 12 gliders, all 
serial numbers, certificated in any category.

(d) Subject

    Joint Aircraft System Component (JASC) Code 3414, Airspeed/Mach 
Indicator.

(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 an airspeed 
indicator (ASI) with speed markings inconsistent with the approved 
and published values (beginning of the white and green arc). The FAA 
is issuing this AD to prevent erroneous information being provided 
to the pilot, particularly at the lower speed operation limits. The 
unsafe condition, if not addressed, could result in reduced control 
of the glider.

(f) Compliance

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

(g) Required Actions

    (1) Within 30 days after the effective date of this AD, inspect 
ASI part number (P/N) IF-W230 or IF-W190 for incorrect markings in 
accordance with the table in the Appendix, ``2.3. Airspeed Indicator 
Markings,'' of Stemme Service Bulletin No. P062-980027, Revision 00, 
dated December 17, 2018 (the SB). If an ASI marking is incorrect, 
before further flight, perform one of the following:
    (i) Replace the ASI by following the Actions, Action 2, of the 
SB; or
    (ii) Amend the existing aircraft flight manual (AFM) for your 
glider by inserting the Appendix, temporary page 2-3 SB, ``2.3. 
Airspeed Indicator Markings,'' of the SB. Within 3 months after 
amending the AFM, replace the ASI by following the Actions, Action 
2, of the SB and remove temporary page 2-3 SB, ``2.3. Airspeed 
Indicator Markings,'' from the AFM.
    (2) As of the effective date of this AD, do not install ASI P/N 
IF-W230 or IF-W190 on any glider unless it has passed the inspection 
required by this AD.

(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 Related Information or email: 
9-AVS-AIR-730-AMOC@faa.gov.
    (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: 
jim.rutherford@faa.gov.
    (2) Refer to European Union Aviation Safety Agency (EASA) AD 
2019-0082, dated April 12, 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-2021-0716.
    (3) For service information identified in this AD, contact 
STEMME AG, Flugplatzstrasse F2, Nr. 6-7, D-15344 Strausberg, 
Germany; phone: +49 (0) 3341 3612-0, fax: +49 (0) 3341 3612-30; 
email: airworthiness@stemme.de; website: https://www.stemme.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 August 20, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-18387 Filed 8-26-21; 8:45 am]
BILLING CODE 4910-13-P