[Federal Register Volume 89, Number 232 (Tuesday, December 3, 2024)]
[Rules and Regulations]
[Pages 95717-95719]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-28178]
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Rules and Regulations
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains regulatory documents
having general applicability and legal effect, most of which are keyed
to and codified in the Code of Federal Regulations, which is published
under 50 titles pursuant to 44 U.S.C. 1510.
The Code of Federal Regulations is sold by the Superintendent of Documents.
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Federal Register / Vol. 89, No. 232 / Tuesday, December 3, 2024 /
Rules and Regulations
[[Page 95717]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-1477; Project Identifier AD-2023-01015-R;
Amendment 39-22880; AD 2024-23-01]
RIN 2120-AA64
Airworthiness Directives; Robinson Helicopter Company
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Robinson Helicopter Company Model R44 and R44 II helicopters.
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. This AD requires inspecting each
bracket and, depending on the results, accomplishing additional
inspections or taking any necessary corrective actions. The FAA is
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective January 7, 2025.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of January 7,
2025.
ADDRESSES:
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 final rule, any comments received, and other
information. The address for Docket Operations is U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
Material Incorporated by Reference:
For Robinson Helicopter Company material identified in
this AD, 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 material 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. It is also available at
regulations.gov under Docket No. FAA-2024-1477.
Other Related Material: For other related Robinson Helicopter
Company material identified in this AD, 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:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain serial-numbered
Robinson Helicopter Company Model R44 and Model R44 II helicopters. The
NPRM published in the Federal Register on June 27, 2024 (89 FR 53534).
The NPRM was prompted by 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.
In the NPRM, the FAA proposed to require, with the fanwheel
removed, inspecting each bracket for looseness and fretting. Depending
on the results of the inspection in the NPRM, the FAA proposed to
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. The FAA is issuing this AD to
address the unsafe condition on these products.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from one commenter, Robinson Helicopter
Company. The following presents the comment received on the NPRM and
the FAA's response to the comment.
Request To Change the Applicability
Robinson Helicopter Company requested the FAA revise the
applicability paragraph to identify only riveted A185-1, A185-2, and
A185-5 brackets. Robinson Helicopter Company stated that some
helicopters within the applicable serial number ranges have been
retrofitted with the latest design installation that utilizes screws as
the method of attachment to the fan scroll housing instead of rivets
and are not subject to this AD.
The FAA agrees and has revised the applicability paragraph of this
AD to clarify that only certain riveted brackets are applicable. The
FAA also added a note to the applicability paragraph of this AD to
further clarify that brackets installed to the fan scroll housing with
screws are not applicable to this AD.
Conclusion
The FAA reviewed the relevant data, considered the comment
received, and determined that air safety requires adopting this AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products. Except for minor editorial changes and
other changes described previously, this AD is adopted as proposed in
the NPRM. None of the
[[Page 95718]]
changes will increase the economic burden on any operator.
Material Incorporated by Reference 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 material
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 is incorporated by reference in this AD. SL-74B is not
incorporated by reference in this AD because this AD does not apply to
Robinson Helicopter Company Model R22 helicopters.
This material 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.
Other Related Material
The FAA reviewed Robinson Helicopter Company R44 Service Bulletin
SB-113, dated March 16, 2023 (SB-113). This material specifies
procedures for inspecting the A185 brackets to ensure the brackets are
attached to the fan scroll housing with \5/32\-inch rivets. This
material 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.
Differences Between This AD and the Referenced Material
This AD requires inspecting the brackets for fretting, and the
fiberglass and rivet holes for delamination, whereas SL-61B does not
contain those actions. SL-61B specifies procedures for repairing the
fan scroll housing rivet holes, whereas this AD requires making that
repair in accordance with FAA-approved procedures.
Costs of Compliance
The FAA estimates that this AD affects 1,686 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 AD.
Inspecting the brackets (three brackets per helicopter) for
looseness and fretting will take 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 will take
0.25 work-hour, for an estimated cost of $21 per helicopter.
If required, replacing the fan scroll housing will take 5 work-
hours and parts will 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 will take 1 work-hour, for an estimated
cost of $85 per helicopter.
If required, replacing a bracket or inner plate will take 1 work-
hour and parts will cost $175, for an estimated cost of $260 per part
replacement.
If required, repairing each rivet hole (per bracket) will take 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 will 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
This AD will not have federalism implications under Executive Order
13132. This AD will 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 this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Will not affect intrastate aviation in Alaska, and
(3) Will 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 Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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:
2024-23-01 Robinson Helicopter Company: Amendment 39-22880; Docket
No. FAA-2024-1477; Project Identifier AD-2023-01015-R.
(a) Effective Date
This airworthiness directive (AD) is effective January 7, 2025.
(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, with riveted belt
tension clutch actuator brackets part number A185-1, A185-2, or
A185-5 (bracket(s)), installed.
Note 1 to paragraph (c): Helicopters with an R44 Cadet
designation are Model R44 helicopters.
Note 2 to paragraph (c): Brackets attached to the fan scroll
housing with screws are not applicable to this AD.
(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 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.
[[Page 95719]]
(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 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
flight crew.
(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 (IBR) of the material listed in this
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this material 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 3 to paragraph (k)(2)(i): The material 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 material identified in this
AD, 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 material 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 November 4, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2024-28178 Filed 12-2-24; 8:45 am]
BILLING CODE 4910-13-P