
[Federal Register Volume 88, Number 233 (Wednesday, December 6, 2023)]
[Proposed Rules]
[Pages 84761-84764]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-26744]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2232; Project Identifier AD-2023-00943-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 R22, R22 Alpha, R22 Beta, 
R22 Mariner, R44, R44 II, and R66 helicopters. This proposed AD was 
prompted by reports of helicopters losing a tail rotor blade (TRB) tip 
cap. This proposed AD would require visually checking and inspecting 
certain part-numbered and serial-numbered TRB tip caps for evidence of 
corrosion and, depending on the results, removing the corrosion. This 
proposed AD would also require removing all affected TRBs from service 
and prohibit installing them on any helicopter. 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 22, 
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-2023-2232; or in person at Docket Operations between 9 
a.m. and

[[Page 84762]]

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.
     For service information identified in this NPRM, 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.

FOR FURTHER INFORMATION CONTACT: James Guo, Aviation Safety Engineer, 
FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (562) 627-
5357; 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-2023-2232; Project Identifier 
AD-2023-00943-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 James 
Guo, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, 
CA 90712; phone: (562) 627-5357; 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 has received three reports of TRB tip caps coming loose due 
to corrosion at the bond on Robinson Helicopter Company Model R44 
helicopters. Due to the similarity of the TRB tip caps on Robinson 
Helicopter Company Model R22, R22 Alpha, R22 Beta, R22 Mariner, R44 II, 
and R66 helicopters, those model helicopters are also affected by this 
issue. According to Robinson Helicopter Company, it has also seen TRBs 
that have corroded to an unserviceable condition, including severe 
leading edge pitting and degradation of the bond at the tip cap. 
Robinson Helicopter Company advises that helicopters operating near 
saltwater are particularly susceptible to corrosion, especially if 
stored outdoors. Affected TRBs were factory-installed or shipped as 
spares prior to November 2022. The three reports include a TRB tip cap 
departing its helicopter. The separate incidents occurred during a run-
up check, after landing, and during a landing on different helicopters. 
Accordingly, this proposed AD would require repetitively checking and 
inspecting the tips caps of TRB part number (P/N) A029-2 with TRB 
serial numbers (S/N) up to 11279 inclusive (P/N A029-2 REV A through U 
inclusive), TRB P/N C029-3 with TRB S/N up to 14329 inclusive (P/N 
C029-3 REV A through Q inclusive), and TRB P/N F029-1 with TRB S/N up 
to 3099 inclusive (P/N F029-1 REV A through F inclusive) for evidence 
of corrosion, removing corrosion, and eventual removal of those TRBs 
from service.
    A debonded TRB tip cap can cause severe vibration and possible 
failure of the tail rotor gearbox housing. This condition, if not 
addressed, could result in increased vibrations, reduced 
controllability, and subsequent loss of 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 designs.

Related Service Information

    The FAA reviewed Robinson Helicopter Company R22 Service Bulletin 
SB-120, R44 Service Bulletin SB-112, and R66 Service Bulletin SB-41, 
each dated December 22, 2022 (SB-120, SB-112, and SB-41). This service 
information specifies procedures for revising the Pilot's Operating 
Handbook of affected helicopters by inserting the included ``Special 
Tail Rotor Tip Preflight Inspection'' page and briefing all pilots and 
maintenance personnel regarding those inspection procedures. This 
service information also specifies procedures for replacing, and 
returning or sending photos of affected TRBs to Robinson Helicopter 
Company.
    The FAA also reviewed Robinson Helicopter Company R22 Service 
Letter SL-93, R44 Service Letter SL-82, and R66 Service Letter SL-40, 
each dated June 30, 2021 (co-published as one document) (SL-93, SL-82, 
and SL-40). This service information specifies procedures for removing 
corrosion from TRBs, applying protectant, balancing TRBs after 
corrosion removal or painting, chemical cleaning TRBs, and tap testing 
the TRB tip cap area.

Proposed AD Requirements in This NPRM

    This proposed AD would require visually checking the TRB tip cap 
area of certain part-numbered and serial-numbered TRBs for an exposed 
tip cap bond line or bubbled paint, repetitively inspecting those TRBs 
for evidence of corrosion and, depending on the results, removing the 
corrosion. The owner/operator (pilot) holding at least a private pilot 
certificate may check the TRB tip caps for an exposed tip cap bond line 
or bubbled paint and must enter compliance with the applicable 
paragraph of the proposed AD into the helicopter maintenance records in 
accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The pilot may 
perform this action because it only involves visually checking the TRB 
tip caps for an exposed tip cap bond line or bubbled paint. This action 
could be performed equally well by a pilot or a mechanic. This is an 
exception to the FAA's standard maintenance regulations.
    This proposed AD would also require removing those TRBs from 
service within 10 months and prohibit installing them on any helicopter 
as of that date.

[[Page 84763]]

Differences Between This Proposed AD and the Service Information

    The effectivity of Robinson Helicopter Company SB-120, SB-112, and 
SB-41 identify the helicopter S/Ns that the affected TRBs were factory-
installed on and the shipping dates of affected TRB spares, whereas 
this proposed AD would apply to the specified model helicopters with 
certain part-numbered and serial-numbered TRBs installed. Robinson 
Helicopter Company SB-120, SB-112, and SB-41 specify revising the 
Pilot's Operating Handbook of affected helicopters and briefing all 
pilots and maintenance personnel regarding the inspection requirements, 
whereas this proposed AD would not require those actions. Robinson 
Helicopter Company SB-120, SB-112, and SB-41 do not specify any visual 
inspections accomplished by a mechanic, whereas this proposed AD would 
require repetitive visual inspections of the TRBs by persons authorized 
under 14 CFR 43.3. Robinson Helicopter Company SB-120, SB-112, and SB-
41 specify replacing, and returning or sending photos of affected TRBs 
by December 31, 2024, whereas this proposed AD would require removing 
affected TRBs from service within 10 months.
    SL-93, SL-82, and SL-40 specify procedures for chemical cleaning 
TRBs, tap testing the TRB tip care area, applying protectant, and 
balancing TRBs after corrosion removal or painting, whereas this 
proposed AD would not require those actions.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 2,701 helicopters of U.S. registry. The FAA estimates the 
following costs to comply with this proposed AD. Labor costs are 
estimated at $85 per work-hour.
    Visually checking or inspecting the TRBs (up to two affected TRBs 
per helicopter) would take about 0.25 work-hour for an estimated cost 
of up to $22 per helicopter per check cycle, for a U.S fleet cost of up 
to $59,422 per check cycle. If required, removing any corrosion would 
take about 2 work-hours and parts would cost about $100 for an 
estimated cost of $270 per TRB. Replacing a TRB would take about 3.5 
work-hours and parts would cost up to about $3,600 for an estimated 
cost of up to $3,898 per TRB.
    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this 
proposed 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:

Robinson Helicopter Company: Docket No. FAA-2023-2232; Project 
Identifier AD-2023-00943-R.

 (a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by January 22, 2024.

 (b) Affected ADs

    None.

 (c) Applicability

    This AD applies to the Robinson Helicopter Company helicopters, 
certificated in any category, identified in paragraphs (c)(1) 
through (3) of this AD.
    (1) Model R22, R22 Alpha, R22 Beta, and R22 Mariner helicopters 
with tail rotor blade (TRB) part number (P/N) A029-2 with TRB serial 
numbers (S/N) up to 11279 inclusive (P/N A029-2 REV A through U 
inclusive), installed;
    (2) Model R44 and R44 II helicopters with TRB P/N C029-3 with 
TRB S/N up to 14329 inclusive (P/N C029-3 REV A through Q 
inclusive), installed; and
    (3) Model R66 helicopters with TRB P/N F029-1 with TRB S/N up to 
3099 inclusive (P/N F029-1 REV A through F inclusive), installed.

 (d) Subject

    Joint Aircraft System Component (JASC) Code 6410, Tail Rotor 
Blades.

 (e) Unsafe Condition

    This AD was prompted by reports of helicopters losing a TRB tip 
cap. The FAA is issuing this AD to detect and prevent TRB tip cap 
failures. The unsafe condition, if not addressed, could result in 
increased vibrations, reduced controllability, 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

    (1) Within 10 hours time-in-service (TIS) after the effective 
date of this AD and thereafter before the first flight of each day, 
visually check each TRB tip cap area (at and adjacent to the tip cap 
bond line on each surface and edge of the TRB) for an exposed tip 
cap bond line or bubbled paint, as depicted in Figure 1 of paragraph 
(g)(1) of this AD. These items may indicate evidence of corrosion. 
The owner/operator (pilot) holding at least a private pilot 
certificate may accomplish this TRB tip cap check and must enter 
compliance with this paragraph of the AD into the helicopter 
maintenance records in accordance with 14 CFR 43.9(a) and 
91.417(a)(2)(v). The record must be maintained as required by 14 CFR 
91.417, 121.380, or 135.439.

[[Page 84764]]

Figure 1 to Paragraph (g)(1)--TRB Tip Cap Check/Inspection
[GRAPHIC] [TIFF OMITTED] TP06DE23.084

    (2) Within 100 hours TIS or during the next 100 hour or annual 
inspection after the effective date of this AD, whichever occurs 
first, and thereafter at intervals not to exceed 100 hours TIS or 
during the next 100 hour or annual inspection, whichever occurs 
first, visually inspect each TRB tip cap area (at and adjacent to 
the tip cap bond line on each surface and edge of the TRB) for 
evidence of corrosion, which may be indicated by an exposed tip cap 
bond line or bubbled paint, as depicted in Figure 1 of paragraph 
(g)(1) of this AD.
    (3) As a result of the actions required by either paragraph 
(g)(1) or (2) of this AD, if there is evidence of corrosion, an 
exposed tip cap bond line, or bubbled paint, before further flight, 
remove all of the corrosion.
    Note 1 to paragraph (g)(3): Robinson Helicopter Company R22 
Service Letter SL-93, R44 Service Letter SL-82, and R66 Service 
Letter SL-40, each dated June 30, 2021 (co-published as one 
document), provide information regarding removing corrosion from 
TRBs.
    (4) Within 10 months of the effective date of this AD, remove 
all TRBs identified in paragraph (c) of this AD from service.
    (5) As of 10 months after the effective date of this AD, do not 
install a TRB identified in paragraph (c) of this AD on any 
helicopter.

 (h) 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 (i)(1) 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.

 (i) Additional Information

    (1) For more information about this AD, contact James Guo, 
Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, 
CA 90712; phone: (562) 627-5357; email: [email protected].
    (2) For service information identified in this AD that is not 
incorporated by reference, 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.

 (j) Material Incorporated by Reference

    None.

    Issued on November 29, 2023.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-26744 Filed 12-5-23; 8:45 am]
BILLING CODE 4910-13-P


