Proposed Rule2022-16192
Airworthiness Directives; Hoffmann GmbH & Co. KG Propellers
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
August 1, 2022
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to supersede Airworthiness Directive (AD) 2021-23-17, which applies to all Hoffmann GmbH & Co. KG (Hoffmann) model HO-V 72 propellers. AD 2021-23-17 requires amending the existing aircraft flight manual (AFM) by inserting abnormal propeller vibration instructions, visual inspection and non-destructive test (NDT) inspection of the propeller hub and, depending on the results of the inspections, replacement of the propeller hub with a part eligible for installation. Since the FAA issued AD 2021-23-17, further investigation by the manufacturer revealed that cracks found on propeller hubs likely resulted from propeller blade retention nuts that were not tightened using published service information during blade installation. This proposed AD would retain the required actions of AD 2021-23-17. This proposed AD would also require a maintenance records review and, depending on the results of the maintenance records review, tightening of each propeller blade retention nut to specific torque values. Depending on the results of the maintenance records review, this proposed AD would require physically inspecting the propeller blade for shake. If any axial play is detected during the performance of the inspection, this proposed AD would require the removal of the propeller from service and the performance of an NDT inspection of the propeller hub. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
<html>
<head>
<title>Federal Register, Volume 87 Issue 146 (Monday, August 1, 2022)</title>
</head>
<body><pre>
[Federal Register Volume 87, Number 146 (Monday, August 1, 2022)]
[Proposed Rules]
[Pages 46903-46906]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-16192]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2022-0980; Project Identifier MCAI-2022-00448-P]
RIN 2120-AA64
Airworthiness Directives; Hoffmann GmbH & Co. KG Propellers
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2021-23-17, which applies to all Hoffmann GmbH & Co. KG (Hoffmann)
model HO-V 72 propellers. AD 2021-23-17 requires amending the existing
aircraft flight manual (AFM) by inserting abnormal propeller vibration
instructions, visual inspection and non-destructive test (NDT)
inspection of the propeller hub and, depending on the results of the
inspections, replacement of the propeller hub with a part eligible for
installation. Since the FAA issued AD 2021-23-17, further investigation
by the manufacturer revealed that cracks found on propeller hubs likely
resulted from propeller blade retention nuts that were not tightened
using published service information during blade installation. This
proposed AD would retain the required actions of AD 2021-23-17. This
proposed AD would also require a maintenance records review and,
depending on the results of the maintenance records review, tightening
of each propeller blade retention nut to specific torque values.
Depending on the results of the maintenance records review, this
proposed AD would require physically inspecting the propeller blade for
shake. If any axial play is detected during the performance of the
inspection, this proposed AD would require the removal of the propeller
from service and the performance of an NDT inspection of the propeller
hub. 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 September
15, 2022.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://www.regulations.gov">www.regulations.gov</a>.
Follow the instructions for submitting comments.
<bullet> Fax: (202) 493-2251.
<bullet> 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.
<bullet> 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 Hoffmann
GmbH & Co. KG, K[uuml]pferlingstrasse 9, 83022, Rosenheim, Germany;
phone: +49 0 8031 1878 0; email: <a href="/cdn-cgi/l/email-protection#84edeae2ebc4ecebe2e2e9e5eaeaa9b8e5a4ecf6e1e2b9" http: prop.com">prop.com</a>">info@hoffmann-<a href="http://prop.com">prop.com</a></a>; website:
<a href="https://hoffmann-<a href="http://prop.com">prop.com</a>">https://hoffmann-<a href="http://prop.com">prop.com</a></a>. You may view this service information at the
FAA, Airworthiness Products Section, Operational Safety Branch, 1200
District Avenue, Burlington, MA 01803. For information on the
availability of this material at the FAA, call (817) 222-5110.
Examining the AD Docket
You may examine the AD docket at <a href="http://www.regulations.gov">www.regulations.gov</a> by searching
for and locating Docket No. FAA-2022-0980; 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 mandatory
continuing airworthiness information (MCAI), any comments received, and
other information. The street address for Docket Operations is listed
above.
FOR FURTHER INFORMATION CONTACT: Michael Schwetz, Aviation Safety
Engineer, Boston ACO Branch, FAA, 1200 District Avenue, Burlington, MA
01803; phone: (781) 238-7761; email: <a href="/cdn-cgi/l/email-protection#320b1f7364611f737b601f7073717d1f717d61725453531c555d44"><span class="__cf_email__" data-cfemail="1c25315d4a4f315d554e315e5d5f53315f534f5c7a7d7d327b736a">[email protected]</span></a>.
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-2022-0980; Project Identifier
MCAI-2022-00448-P'' 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
<a href="http://www.regulations.gov">www.regulations.gov</a>, including any personal information you provide.
The
[[Page 46904]]
agency will also post a report summarizing each substantive verbal
contact we receive about this proposed AD.
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
Michael Schwetz, Aviation Safety Engineer, Boston ACO Branch, FAA, 1200
District Avenue, Burlington, MA 01803. 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 2021-23-17, Amendment 39-21815 (86 FR 68905,
December 6, 2021), (AD 2021-23-17), for all Hoffmann GmbH & Co. KG
model HO-V 72 propellers. AD 2021-23-17 was prompted by reports of
cracks at different positions on two affected propeller hubs. AD 2021-
23-17 requires amending the existing AFM by inserting abnormal
propeller vibration instructions, visual inspection and NDT inspection
of the propeller hub and, depending on the results of the inspections,
replacement of the propeller hub with a part eligible for installation.
The agency issued AD 2021-23-17 to prevent failure of the propeller
hub.
Actions Since AD 2021-23-17 Was Issued
Since the FAA issued AD 2021-23-17, the European Union Aviation
Safety Agency (EASA), which is the Technical Agent for the Member
States of the European Community, has issued EASA AD 2022-0061, dated
April 4, 2022 (referred to after this as ``the MCAI''), to address the
unsafe condition on these products. The MCAI states:
Cracks have been reported at different positions on two affected
parts, both installed on Slingsby T67 ``Firefly'' aeroplanes. One
crack was found during scheduled inspection, the other crack during
an unscheduled inspection after abnormal vibrations occurred.
Subsequent investigation determined that improper tightening of
blade nuts has caused or contributed to those events.
This condition, if not detected and corrected, could lead to in-
flight propeller detachment, possibly resulting in damage to the
aeroplane and/or injury to persons on the ground.
To address this potential unsafe condition, Hoffmann Propeller
issued the SB, providing applicable instructions, and EASA issued
Emergency AD 2020-0226-E (later revised [to EASA AD 2020-0226R1]) to
require inspections of affected parts and, depending on findings,
replacement. That AD also required, for certain aeroplanes,
amendment of the applicable Aircraft Flight Manual (AFM).
Since that [EASA] AD was issued, further investigation revealed
that not all propeller blade nuts were tightened in accordance with
the Hoffman Propeller blade nut tightening procedure B2.23 which
requires a certain over-torquing and loosening of the blade nut to
limit a preload reduction due to material settlement. Prompted by
this development, Hoffmann Propeller issued SB057 (incorporating
blade nut tightening procedure B2.23) providing torquing
instructions, and SB58 providing instructions for setting correct
counterweight angles. Additionally, Hoffmann Propeller issued the
torque tightening SB (referencing SB57 and SB58) providing
inspections and corrective action instructions.
For the reasons described above, this [EASA] AD retains the
requirements of EASA AD 2020-0226R1, which is superseded, and
requires additional blade checks, inspections, and re-tightening of
the propeller blade nuts.
You may obtain further information by examining the MCAI in the AD
docket at <a href="http://www.regulations.gov">www.regulations.gov</a> by searching for and locating Docket No.
FAA-2022-0980.
FAA's Determination
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 the following service information:
<bullet> Hoffmann Propeller Service Bulletin SB057 C, dated
February 22, 2022. This SB specifies procedures for tightening the
propeller blade retention nut.
<bullet> Hoffmann Propeller Service Bulletin SB059 B, dated
February 23, 2022. This SB specifies procedures for tightening the
propeller blade retention nut with the correct torque and inspecting
the propeller blade for shake.
This proposed AD would also require Hoffmann Propeller GmbH & Co.
KG Service Bulletin SB E53 Rev. D, dated February 18, 2021, which was
previously approved by the Director of the Federal Register for
incorporation by reference on January 10, 2022 (86 FR 68905, December
6, 2021). The service bulletin describes procedures for visual and NDT
inspections of the propeller hub for cracks.
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 reviewed the following service information:
<bullet> Hoffmann Propeller Service Bulletin SB058 A, dated
February 2, 2022. This SB specifies the updated definition of the
counterweight angle.
Proposed AD Requirements in This NPRM
This proposed AD would retain all of the requirements of AD 2021-
23-17. This proposed AD would also require a maintenance records review
and, depending on the results of the maintenance records review,
tightening of each propeller blade retention nut to specified torque
values. Depending on the results of the maintenance records review,
this proposed AD would require initial and repetitive physical
inspections of the propeller blade for shake. If any axial play is
detected during inspection, this proposed AD would require the removal
of the propeller from service and the performance of an NDT inspection
of the propeller hub.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 35 propellers installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
AD:
[[Page 46905]]
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
Amend AFM............................. 1 work-hour x $85 per $0 $85 $2,975
hour = $85.
Visually inspect propeller hub........ 1 work-hour x $85 per 0 85 2,975
hour = $85.
NDT inspect propeller hub............. 8 work-hours x $85 per 0 680 23,800
hour = $680.
Review maintenance records............ 0.5 work-hours x $85 per 0 42.50 1,487.50
hour = $42.50.
----------------------------------------------------------------------------------------------------------------
The FAA estimates the following costs to do any necessary actions
that would be required based on the results of the proposed
inspections. The agency has no way of determining the number of
aircraft that might need these actions:
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product
----------------------------------------------------------------------------------------------------------------
Replace propeller hub......................... 5 work-hours x $85 per hour = $1,600 $2,025
$425.
Inspect propeller blade for shake............. 0.25 work-hours x $85 per hour = 0 21.25
$21.25.
Tighten propeller blade retention nuts........ 2 work-hours x $85 per hour = 0 170
$170.
----------------------------------------------------------------------------------------------------------------
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
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:
0
a. Removing Airworthiness Directive 2021-23-17, Amendment 39-21815 (86
FR 68905, December 6, 2021); and
0
b. Adding the following new airworthiness directive:
Hoffmann GmbH & Co. KG: Docket No. FAA-2022-0980; Project Identifier
MCAI-2022-00448-P.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) action by September 15, 2022.
(b) Affected ADs
This AD replaces AD 2021-23-17, Amendment 39-21815 (86 FR 68905,
December 6, 2021) (AD 2021-23-17).
(c) Applicability
This AD applies to Hoffmann GmbH & Co. KG (Hoffmann) model HO-V
72 propellers.
(d) Subject
Joint Aircraft System Component (JASC) Code 6114, Propeller Hub
Section.
(e) Unsafe Condition
This AD was prompted by reports of cracks at different positions
on two affected propeller hubs. The FAA is issuing this AD to
prevent failure of the propeller hub. The unsafe condition, if not
addressed, could result in release of the propeller, damage to the
airplane, and injury to persons on the ground.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) Before the next flight after December 22, 2020 (the
effective date of AD 2020-25-05, Amendment 39-21347 (85 FR 78702,
December 7, 2020)), amend the emergency or abnormal procedures
section of the existing aircraft flight manual by inserting this
text: ``Abnormal propeller vibrations: As applicable, reduce engine
RPM.''
(2) Before the next flight after January 10, 2022 (the effective
date of AD 2021-23-17), and thereafter, before the next flight after
any flight where abnormal propeller vibrations have been
experienced, visually inspect propeller hub HO-V 72 ( ) ( )-( )-( )
for cracks using paragraph 2.1 of Hoffmann Propeller GmbH & Co. KG
Service Bulletin SB E53, Rev. D, dated February 18, 2021 (Hoffmann
Propeller SB E53 Rev. D).
(3) Within 20 flight hours (FHs) after January 10, 2022 (the
effective date of AD 2021-23-17), perform a non-destructive test
(NDT) inspection of propeller hub HO-V 72 ( ) ( )-( )-( ) using
paragraph 2.3 of Hoffmann Propeller SB E53 Rev. D.
(4) During each overhaul of propeller hub HO-V 72 ( ) ( )-( )-(
) after January 10, 2022 (the effective date of AD 2021-23-17),
perform an NDT inspection using paragraph 2.3 of Hoffmann Propeller
SB E53 Rev. D.
(5) Within 30 days after the effective date of this AD, review
the maintenance records
[[Page 46906]]
to confirm the propeller blade retention nuts were tightened at the
last in-shop maintenance visit to the torque values in paragraph 5
of Hoffmann Propeller Service Bulletin SB057 C, dated February 22,
2022 (Hoffmann Propeller SB057 C).
(6) If, during the records review required by paragraph (g)(5)
of this AD, it is determined that the propeller blade retention nuts
were not tightened to the torque values in paragraph 5 of Hoffmann
Propeller SB057 C, or it cannot be confirmed if the propeller blade
retention nuts were tightened to the torque values in paragraph 5 of
Hoffmann Propeller SB057 C, perform the following actions:
(i) Within 90 FHs after the effective date of this AD, tighten
each propeller blade retention nut to the torque values in paragraph
5 of Hoffmann Propeller SB057 C, using paragraphs 6 and 7 of
Hoffmann Propeller Service Bulletin SB059 B, dated February 23,
2022.
(ii) Before the next flight after the effective date of this AD
and, thereafter, before each flight until the propeller blade
retention nut is tightened to the torque values in paragraph 5 of
Hoffmann Propeller SB057 C, as required by paragraph (g)(6)(i) of
this AD, confirm that there is no axial play in the blade retention
system by inspecting the propeller blade for shake. If any axial
play is detected, remove the propeller from service and perform an
NDT inspection of the propeller hub using paragraph 2.3 of Hoffmann
Propeller SB E53 Rev. D.
(7) If, during any inspection required by paragraph (g)(2), (3),
(4) or (6)(ii) of this AD, any crack is detected, replace propeller
hub HO-V 72 ( ) ( )-( )-( ) with a part eligible for installation.
(h) Definition
For the purpose of this AD, a ``part eligible for installation''
is a propeller hub HO-V 72 ( ) ( )-( )-( ) with zero hours time
since new, or a propeller hub HO-V 72 ( ) ( )-( )-( ) that has
passed an NDT inspection using paragraph 2.3 of Hoffmann Propeller
SB E53 Rev. D.
(i) Non-Required Actions
(1) Sending the propeller to Hoffmann for investigation, as
contained in paragraph 2.1 of Hoffmann Propeller SB E53 Rev. D, is
not required by this AD.
(2) Reporting propeller hubs with cracks to Hoffmann, as
contained in paragraph 2.3 of Hoffmann Propeller SB E53 Rev. D, is
not required by this AD.
(j) Credit for Previous Actions
(1) You may take credit for the initial visual inspection and
NDT inspection of the propeller hub required by paragraphs (g)(2),
(3), and (4) of this AD if you performed any of these actions before
January 10, 2022 (the effective date of AD 2021-23-17) using
Hoffmann Propeller GmbH & Co. KG SB E53, Rev. A, dated October 9,
2020; Rev. B, dated October 14, 2020; or Rev. C, dated December 9,
2020.
(2) You may take credit for the records review to confirm the
propeller blade retention nuts were tightened to the torque values
as required by paragraph (g)(5) of this AD, and the tightening of
each propeller blade retention nut as required by paragraph
(g)(6)(i) of this AD if you performed any of these actions before
the effective date of this AD during the last in-shop maintenance
visit using Hoffmann Propeller Service Bulletin SB057 B, dated
February 8, 2022; Hoffmann Propeller Service Bulletin SB059 A, dated
February 11, 2022; or Hoffmann Propeller Service Bulletin SB059 B,
dated February 23, 2022.
(k) Special Flight Permit
A special flight permit may be issued in accordance with 14 CFR
21.197 and 21.199 to operate the airplane to a service facility to
perform the NDT inspection. Special flight permits are prohibited to
perform the visual inspection of the propeller hub.
(l) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Boston ACO 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 (m)(1) of this AD.
(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.
(m) Related Information
(1) For more information about this AD, contact Michael Schwetz,
Aviation Safety Engineer, Boston ACO Branch, FAA, 1200 District
Avenue, Burlington, MA 01803; phone: (781) 238-7761; email: <a href="/cdn-cgi/l/email-protection#aa9387ebfcf987ebe3f887e8ebe9e587e9e5f9eacccbcb84cdc5dc"><span class="__cf_email__" data-cfemail="073e2a4651542a464e552a454644482a4448544761666629606871">[email protected]</span></a>.
(2) Refer to European Union Aviation Safety Agency (EASA) AD
2022-0061, dated April 4, 2022, for more information. You may
examine the EASA AD in the AD docket at <a href="http://www.regulations.gov">www.regulations.gov</a> by
searching for and locating it in Docket No. FAA-2022-0980.
(3) For service information identified in this AD, contact
Hoffmann GmbH & Co. KG, K[uuml]pferlingstrasse 9, 83022, Rosenheim,
Germany; phone: +49 0 8031 1878 0; email: <a href="/cdn-cgi/l/email-protection#95fcfbf3fad5fdfaf3f3f8f4fbfbb8a9f4b5fde7f0f3a8" http: prop.com">prop.com</a>">info@hoffmann-<a href="http://prop.com">prop.com</a></a>;
website: <a href="https://hoffmann-<a href="http://prop.com">prop.com</a>">https://hoffmann-<a href="http://prop.com">prop.com</a></a>. You may view this referenced
service information at the FAA, Airworthiness Products Section,
Operational Safety Branch, 1200 District Avenue, Burlington, MA
01803. For information on the availability of this material at the
FAA, call (817) 222-5110.
Issued on July 22, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2022-16192 Filed 7-29-22; 8:45 am]
BILLING CODE 4910-13-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on August 1, 2022.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.