[Federal Register Volume 89, Number 124 (Thursday, June 27, 2024)]
[Proposed Rules]
[Pages 53534-53536]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-11610]


 ========================================================================
 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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  Federal Register / Vol. 89, No. 124 / Thursday, June 27, 2024 / 
Proposed Rules  

[[Page 53534]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-1477; Project Identifier AD-2023-01015-R]
RIN 2120-AA64


Airworthiness Directives; Robinson Helicopter Company Helicopters

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 Robinson Helicopter Company Model R44 and R44 II 
helicopters. This proposed AD was prompted by several reports of failed 
clutch actuators and failed rivets attaching the belt tension clutch 
actuator brackets (bracket) to the fan scroll housing. This proposed AD 
would require inspecting each bracket and, depending on the results, 
accomplishing additional inspections or taking any necessary corrective 
actions. 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 August 12, 
2024.

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 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.
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-1477; 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, any comments received, and other 
information. The street address for Docket Operations is listed above.
    Material Incorporated by Reference:
     For Robinson Helicopter Company service information, 
contact Robinson Helicopter Company, Technical Support Department, 2901 
Airport Drive, Torrance, CA 90505; phone (310) 539-0508; fax (310) 539-
5198; email robinsonheli.com">ts1@robinsonheli.com; or at robinsonheli.com.
     You may view this service information at the FAA, Office 
of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 
6N-321, Fort Worth, TX 76177. For information on the availability of 
this material at the FAA, call (817) 222-5110.
    Other Related Service Information: For additional Robinson 
Helicopter Company service information, use the Robinson Helicopter 
Company contact information under Material Incorporated by Reference 
above.

FOR FURTHER INFORMATION CONTACT: Charles Ayala, Aviation Safety 
Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: 
(562) 627-5226; 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-2024-1477; Project Identifier 
AD-2023-01015-R'' 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 
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 
Charles Ayala, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, 
Lakewood, CA 90712; phone: (562) 627-5226; email: 
[email protected]. 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 received five reports of failed clutch actuators and failed 
rivets attaching the clutch actuator bracket, part number A185-1, A185-
2, and A185-5 (bracket), to the fan scroll housing on Robinson 
Helicopter Company Model R44 II helicopters. According to Robinson 
Helicopter Company, in all of these occurrences, the bracket separated 
from the fan scroll housing. In four of the reports, this separation of 
the bracket caused a failure of the belt tension actuator. Further 
investigation revealed the failure of the rivets attaching the bracket 
to the fan scroll housing was caused by excessive vibration of the fan 
scroll housing due to the design of the fan scroll housing, including 
the quantity and size of the rivets. Because of design similarity, 
Robinson Helicopter Company Model R44 helicopters are also affected by 
this unsafe condition.
    Accordingly, the FAA proposes to adopt a new AD for certain serial-

[[Page 53535]]

numbered Robinson Helicopter Company Model R44 and R44 II helicopters 
to detect and correct loose and missing brackets and rivets. 
Helicopters with subsequent serial numbers were manufactured with steel 
hex-drive screws attaching the brackets to the scroll instead of 
rivets, and therefore are not susceptible to rivet failures. This 
condition, if not addressed, could result in detachment of the bracket 
causing failure of the clutch actuator assembly, loss of main and tail 
rotor drive, and subsequent loss control of the helicopter.

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 Robinson Helicopter Company R22 Service Letter SL-
74B (SL-74B), and R44 Service Letter SL-61B (SL-61B), each Revision B 
and dated March 16, 2023 (co-published as one document). This service 
information specifies procedures for inspecting the A185 brackets for 
looseness and ensuring that a total of 12 rivets attach the A185 
brackets to the fan scroll housing, and corrective actions as necessary 
including repairing rivet holes; replacing the scroll; replacing any 
\1/8\-inch rivets with \5/32\-inch rivets; enlarging rivet holes; and 
applying a torque seal. SL-61B would be incorporated by reference in 
this proposed AD; SL-74B would not be incorporated by reference in this 
proposed AD because this proposed AD would not apply to Robinson 
Helicopter Company Model R22 helicopters.
    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 Robinson Helicopter Company R44 Service 
Bulletin SB-113, dated March 16, 2023 (SB-113). This service 
information specifies procedures for inspecting the A185 brackets to 
ensure the brackets are attached to the fan scroll housing with \5/32\-
inch rivets. This service information also specifies repairing the 
scroll if there are less than 12 rivets, if \5/32\-inch rivets are not 
installed, if the brackets are loose, or if there is any fretting.

Proposed AD Requirements in This NPRM

    For certain Robinson Helicopter Company Model R44 and R44 II 
helicopters, this proposed AD would require, with the fanwheel removed, 
inspecting each bracket for looseness and fretting. Depending on the 
results, this proposed AD would require additional actions such as 
inspecting the fiberglass and rivet holes of the fan scroll housing for 
delamination, inspecting the quantity and size of the fan scroll 
housing rivets, replacing the fan scroll housing, replacing brackets 
and rivets, and applying a horizontal torque stripe to each rivet.

Differences Between This Proposed AD and the Service Information

    This proposed AD would require inspecting the brackets for fretting 
and the fiberglass and rivet holes for delamination, and SL-61B does 
not contain those actions. SL-61B specifies procedures for repairing 
the fan scroll housing rivet holes, whereas this proposed AD would 
require making that repair in accordance with FAA-approved procedures.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 1,686 helicopters of U.S. registry. Labor rates are estimated at 
$85 per work-hour. Based on these numbers, the FAA estimates the 
following costs to comply with this proposed AD.
    Inspecting the brackets (three brackets per helicopter) for 
looseness and fretting would take approximately 0.25 work-hour, for an 
estimated cost of $21 per helicopter and $35,406 for the U.S. fleet.
    If required, inspecting the fiberglass for delamination would take 
approximately 0.25 work-hour, for an estimated cost of $21 per 
helicopter.
    If required, replacing the fan scroll housing would take 
approximately 5 work-hours and parts would cost $3,720, for an 
estimated cost of $4,145 per helicopter.
    If required, inspecting all brackets, each inner plate, and each 
fan scroll housing rivet hole would take approximately 1 work-hour, for 
an estimated cost of $85 per helicopter.
    If required, replacing a bracket or inner plate would take 
approximately 1 work-hour and parts would cost approximately $175, for 
an estimated cost of $260 per part replacement.
    If required, repairing each rivet hole (per bracket) would take 
approximately 1.5 work-hours for an estimated cost of $128 per bracket.
    Replacing a rivet (if required) and applying a torque stripe to 
each rivet would each take a minimal amount of time with a nominal 
parts cost.

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.

[[Page 53536]]

Sec.  39.13  [Amended]

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

Robinson Helicopter Company: Docket No. FAA-2024-1477; Project 
Identifier AD-2023-01015-R.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by August 12, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Robinson Helicopter Company Model R44 
helicopters serial numbers (S/Ns) up to 2480 inclusive and 30001 
through 30022 inclusive, and Model R44 II helicopters S/Ns up to 
14089 inclusive, certificated in any category.
    Note 1 to paragraph (c): Helicopters with an R44 Cadet 
designation are Model R44 helicopters.

(d) Subject

    Joint Aircraft System Component (JASC) Code: 6300, Main rotor 
drive system and 6700, Rotorcraft flight control.

(e) Unsafe Condition

    This AD was prompted by several reports of failed clutch 
actuators and failed rivets attaching the belt tension clutch 
actuator brackets (bracket) to the fan scroll housing. The FAA is 
issuing this AD to detect and address loose and missing brackets and 
rivets. The unsafe condition, if not addressed, could result in 
detachment of the bracket, causing failure of the clutch actuator 
assembly, loss of main and tail rotor drive, and subsequent loss of 
control of the helicopter.

(f) Compliance

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

(g) Required Actions

    Within 300 hours time-in-service or 12 months after the 
effective date of this AD, whichever occurs first, with the fanwheel 
removed, inspect each bracket part number A185-1, A185-2, and A185-5 
(bracket) installed on the fan scroll housing for looseness (bracket 
can be moved by hand) and fretting and accomplish the actions in 
paragraphs (g)(1) or (2) of this AD, as applicable.
    (1) If there is no looseness of any bracket and no fretting, 
before further flight, visually inspect the fiberglass adjacent to 
the rivets of the fan scroll housing for delamination.
    (i) If there is any delamination in the fiberglass, before 
further flight, remove the fan scroll housing from service and 
install an airworthy fan scroll housing using \5/32\-inch rivets (3 
rivets on each top bracket and 6 rivets on the bottom bracket). 
Figure 1 of Robinson Helicopter Company R44 Service Letter SL-61B, 
Revision B, dated March 16, 2023 (SL-61B) depicts the location of 
each bracket and rivet.
    (ii) If there is no delamination in the fiberglass, before 
further flight, inspect for the installation of \5/32\-inch rivets 
in all 12 locations (3 rivets on each top bracket and 6 rivets on 
the bottom bracket) depicted in Figure 1 of SL-61B. If a \5/32\-inch 
rivet is not installed in all 12 locations, before further flight, 
replace each incorrectly sized rivet and each missing rivet with a 
\5/32\-inch rivet.
    (iii) Apply a horizontal torque stripe to each rivet.
    (2) If any bracket is loose or has any fretting, before further 
flight, remove all brackets and inner plates from the fan scroll 
housing and accomplish the actions in paragraphs (g)(2)(i) through 
(iv) of this AD.
    (i) For each bracket with fretting, before further flight, 
remove the bracket from service and replace it with an airworthy 
bracket.
    (ii) Visually inspect each bracket and inner plate for cracks 
and deformation, visually inspect the fiberglass adjacent to the 
rivets of the fan scroll housing for delamination, and visually 
inspect each fan scroll housing rivet hole for delamination and 
other damage, which may be indicated by fretting.
    (A) If a bracket or inner plate has any cracks or deformation, 
before further flight, remove the affected part from service and 
replace it with an airworthy part.
    (B) If there is any delamination in the fiberglass or in any fan 
scroll housing rivet hole, before further flight, remove the fan 
scroll housing from service and install an airworthy fan scroll 
housing using \5/32\-inch rivets (3 rivets on each top bracket and 6 
rivets on the bottom bracket). Figure 1 of SL-61B depicts the 
location of each bracket and rivet.
    (C) If there is other damage in any fan scroll housing rivet 
hole, before further flight, repair the rivet hole in accordance 
with FAA-approved procedures.
    (iii) After accomplishing the actions in paragraphs (g)(2)(i) 
and (ii) of this AD, when installing or reinstalling the brackets 
and inner plates on the fan scroll housing, use \5/32\-inch rivets 
in all 12 locations depicted in Figure 1 of SL-61B (3 rivets on each 
top bracket and 6 rivets on the bottom bracket).
    (iv) Apply a horizontal torque stripe to each rivet.

(h) Special Flight Permits

    A one-time special flight permit may be issued in accordance 
with 14 CFR 21.197 and 21.199 to fly the aircraft to a location 
where the actions required by this AD can be accomplished. This 
flight must be a non-revenue flight and limited to only essential 
flightcrew.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, West Certification 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 West Certification Branch, send it to 
the attention of the person identified in paragraph (j) of this AD. 
Information may be emailed to: [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

    For more information about this AD, contact Charles Ayala, 
Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, 
CA 90712; phone: (562) 627-5226; email: [email protected].

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the service information listed in this 
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Robinson Helicopter Company R44 Service Letter SL-61B, 
Revision B, dated March 16, 2023.
    Note 2 to paragraph (k)(2)(i): The service information 
identified in paragraph (k)(2)(i) of this AD is co-published as one 
document along with Robinson Helicopter Company R22 Service Letter 
SL-74B, Revision B, dated March 16, 2023, which is not incorporated 
by reference in this AD.
    (ii) [Reserved]
    (3) For Robinson Helicopter Company service information, contact 
Robinson Helicopter Company, Technical Support Department, 2901 
Airport Drive, Torrance, CA 90505; phone (310) 539-0508; fax (310) 
539-5198; email robinsonheli.com">ts1@robinsonheli.com; or at robinsonheli.com.
    (4) You may view this service information at the FAA, Office of 
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Fort 
Worth, TX 76177. For information on the availability of this 
material at the FAA, call (817) 222-5110.
    (5) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on May 21, 2024.
James D. Foltz,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-11610 Filed 6-26-24; 8:45 am]
BILLING CODE 4910-13-P