[Federal Register Volume 89, Number 39 (Tuesday, February 27, 2024)]
[Rules and Regulations]
[Pages 14377-14379]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-03920]



[[Page 14377]]

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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; 
Amendment 39-22681; AD 2024-04-02]
RIN 2120-AA64


Airworthiness Directives; Robinson Helicopter Company Helicopters

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 R22, R22 Alpha, R22 Beta, R22 
Mariner, R44, R44 II, and R66 helicopters. This AD was prompted by 
reports of helicopters losing a tail rotor blade (TRB) tip cap. This AD 
requires 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 AD also requires removing 
all affected TRBs from service and prohibits installing them on any 
helicopter. The FAA is issuing this AD to address the unsafe condition 
on these products.

DATES: This AD is effective April 2, 2024.

ADDRESSES: 
    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 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.
    Related Service Information:
     For service information identified in this final rule, 
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 website 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:

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 Robinson 
Helicopter Company Model R22, R22 Alpha, R22 Beta, R22 Mariner, R44, 
R44 II, and R66 helicopters. The NPRM published in the Federal Register 
on December 6, 2023 (88 FR 84761). The NPRM was prompted by 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.
    In the NPRM, the FAA proposed to 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. The owner/operator (pilot) holding at least a private 
pilot certificate may accomplish the check of the TRB tip caps and must 
enter compliance with the applicable paragraph of this 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.
    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. The 
FAA is issuing this AD to address the unsafe condition on these 
products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the costs.

Conclusion

    The FAA reviewed the relevant data 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, this AD is adopted as proposed in the NPRM.

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.

Differences Between This 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

[[Page 14378]]

spares, whereas this AD applies 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 AD does 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 AD requires 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 AD requires 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 AD 
does not require those actions.

Costs of Compliance

    The FAA estimates that this AD affects 2,701 helicopters of U.S. 
registry. The FAA estimates the following costs to comply with this AD. 
Labor costs are estimated at $85 per work-hour.
    Visually checking or inspecting the TRBs (up to two affected TRBs 
per helicopter) will take approximately 0.25 work-hour for an estimated 
cost of up to $22 per helicopter per cycle, for a U.S fleet cost of up 
to $59,422 per cycle. If required, removing any corrosion will take 
approximately 2 work-hours and the parts will cost approximately $100 
for an estimated cost of $270 per TRB. Replacing a TRB will take 
approximately 3.5 work-hours and the parts will cost up to 
approximately $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 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

    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:

2024-04-02 Robinson Helicopter Company: Amendment 39-22681; Docket 
No. FAA-2023-2232; Project Identifier AD-2023-00943-R.

(a) Effective Date

    This airworthiness directive (AD) is effective April 2, 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 to 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 14379]]

Figure 1 to Paragraph (g)(1)--TRB Tip Cap Check/Inspection
[GRAPHIC] [TIFF OMITTED] TR27FE24.000

    (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 to 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 website 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 February 13, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-03920 Filed 2-26-24; 8:45 am]
BILLING CODE 4910-13-P