[Federal Register Volume 89, Number 140 (Monday, July 22, 2024)]
[Rules and Regulations]
[Pages 58962-58964]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-16012]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1891; Project Identifier AD-2023-00612-R; 
Amendment 39-22774; AD 2024-12-10]
RIN 2120-AA64


Airworthiness Directives; Centerpointe Aerospace Inc. 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 all 
Centerpointe Aerospace Inc. (Centerpointe) Model S-58BT, S-58DT, S-
58ET, S-58FT, S-58HT, and S-58JT helicopters. This AD was prompted by 
an indication of a crack on the angle gearbox mount (AGBM). This AD 
requires repetitively performing a fluorescent penetrant inspection 
(FPI) of the AGBM at specified time intervals and, depending on the 
results, removing the AGBM from service. The FAA is issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective August 26, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of August 26, 
2024.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-1891; 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 Centerpointe Aerospace service information identified 
in this AD, contact Centerpointe Aerospace Inc., 279 Blackland Road, 
Fate, TX 75189; phone: (972) 636-9601; email: 
[email protected]; website: californiahelicopter.com.
     You may view this service information at the FAA, Regional 
Counsel, Southwest Region, 10101 Hillwood Pkwy., 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-2023-1891.

FOR FURTHER INFORMATION CONTACT: Jacob Fitch, Aviation Safety Engineer, 
FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; phone: (817) 222-4130; 
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 all Centerpointe Model 
S-58BT, S-58DT,
    S-58ET, S-58FT, S-58HT, and S-58JT helicopters. The NPRM published 
in the Federal Register on October 3, 2023 (88 FR 68002). The NPRM was 
prompted by fatigue cracking that was found on a Model S-58BT 
helicopter during a preflight inspection. The fatigue cracking was 
found in the angle supports and cross-members forming the edges of the 
AGBM. Due to their similarity to the Model S-58BT helicopter, the FAA 
determined that Centerpointe Model S-58DT, S-58ET, S-58FT, S-58HT, and 
S-58JT helicopters are also affected by the same unsafe condition. In 
the NPRM, the FAA proposed to require repetitive FPIs of the AGBM for a 
crack. The FAA is issuing this AD to address the unsafe condition on 
these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from one commenter, Midwest Helicopter 
Airways, Inc. (Midwest). Midwest disagrees with the FAA's determination 
of the unsafe condition in the proposed AD and opines that a 
supplemental enhanced visual inspection in addition to inspections 
performed on the AGBM during routine maintenance is sufficient. The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.

Request To Change the Unsafe Condition

    Midwest stated its opinion that the root cause for the failure of 
the AGBM structural member was not a result of fatigue cracking, but 
was due to improper installation, routing, or securing of an electrical 
wire. Midwest submitted photos sent from a

[[Page 58963]]

representative of Centerpointe Aerospace to current S-58T operators 
that show abrasions in several locations on the failed angle support 
structure. According to Midwest, these abrasion marks look to be the 
result of a wire shown in the photos not properly routed or secured, 
that began to wear into the structural member. Several abrasions can be 
seen in the photo just above the crack with a larger abrasion being 
directly at the crack of the structure. Midwest stated that the chafing 
marks shown in the photos indicate improper installation, routing, or 
securing of an electrical wire and other damage from unsecured wiring 
and advises that wire installation requirements regarding chafing on 
the airframe are specified in the Acceptable Methods, Techniques, and 
Practices Aircraft Inspection and Repair, FAA Advisory Circular 43.13-
1B Chg. I, Chapter 11, Section 8, Paragraph 11.96(q), which states: 
``Ensure that wires and cables are routed in such a manner that chafing 
will not occur against the airframe or other components.''
    The FAA disagrees with the comments regarding the cause of the 
unsafe condition as evidence shows that fatigue and not chafing is the 
root cause of the crack found on the AGBM. Additionally, there are 
other likely crack initiation points in the structure of the cracked 
AGBM leg that can be seen in other photos. The FAA did not change this 
AD as a result of this comment.

Comment Regarding Compliance With the Service Information

    Midwest's second comment pertains to compliance with the proposed 
AD to perform the procedures specified in Centerpointe Aerospace 
Service Bulletin No. 58B75, dated April 26, 2023 (SB58B75). Midwest 
states that the proposed AD would require specific procedures to be 
performed which are outlined in SB58B75; that compliance with the SB 
would require replacement of the AGBM assembly, if the affected part is 
cracked; and that replacing the AGBM would remove privileges the 
maintenance organization and technicians have under their 
certifications and repair abilities. Midwest further states that 
SB58B75 does not provide guidance with regards to blending of material, 
removal of corrosion, or limitations for repair of the AGBM. 
Additionally, Midwest states that SB58B75 requires a qualified engineer 
to provide guidance, without explanation of what qualifications must be 
obtained to determine airworthiness. Midwest then states that SB58B75 
does not address preparation of the structure for the inspection to be 
completed and that this would potentially cause delays in service and 
additional costs to operators. Instead of compliance with SB58B75, 
Midwest suggests thoroughly cleaning and conducting a visual inspection 
for damage to the mounting structure including gouges, dents, 
deformity, chafing, loose fasteners, and corrosion. If gouging or 
chafing, caused by plumbing or wiring, are evident, Midwest suggests 
taking action to remove or reposition the cause of the discrepancy and 
evaluate the discrepancy of the mount for limitations of wear. In 
addition, Midwest suggests an enhanced visual inspection using a 10-
power magnification device and a bright light to identify potential 
cracks; primarily inspecting the areas around the fastener holes and 
attaching hardware. Subsequently, if this visual or enhanced inspection 
results in a suspected crack, Midwest suggests verifying using an FPI, 
as specified in SB58B75. Additionally, Midwest states based on the 
historical data of the S-58T helicopters, that the AGBM is a durable 
structure, and this unsafe condition is unlikely to exist or develop on 
any S-58T or similar model helicopter.
    The FAA would like to clarify that this AD refers to SB58B75 for 
the locations of the eight inspection areas only. The AD requires 
performing an FPI of the areas shown in figures in SB58B75 by a Level 
II or Level III inspector certified in the FAA-acceptable standards for 
nondestructive inspection personnel; it is understood that the 
accomplishment of the FPI must be done with acceptable procedures. An 
alternative method of compliance (AMOC) under the provisions of 
paragraph (h) of this AD may be requested. The FAA did not change this 
AD as a result of this comment.

Conclusion

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

Related Service Information Under 1 CFR Part 51

    The FAA reviewed SB58B75, which specifies procedures for 
repetitively performing an FPI and reporting the results to the 
manufacturer. 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 the ADDRESSES section.

Differences Between This AD and the Service Information

    Where the service information specifies that the initial FPI be 
performed within 120 days after receipt of the service information, 
this AD requires the initial FPI to be performed within 250 hours time-
in-service. The service information specifies reporting the results of 
the FPI to the manufacturer, whereas this AD does not.
    Where the service information requires compliance with the 
Procedures in the Accomplishment Instructions specified in the service 
bulletin, this AD requires accomplishing the Required Actions specified 
in paragraph (g) of this AD using standard procedures and Figures 1A 
and 1B of the Accomplishment Instructions of the service bulletin.

Costs of Compliance

    The FAA estimates that this AD affects 14 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 AD.
    Performing an FPI of the AGBM takes about 5 work-hours and parts 
cost $150 for an estimated cost of $575 per helicopter, and $8,050 for 
the U.S. fleet, per inspection cycle.
    If necessary, replacing an AGBM takes about 41 work-hours and parts 
cost are approximately $30,000, for an estimated cost of $33,485 per 
helicopter.

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.

[[Page 58964]]

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:

2024-12-10 Centerpointe Aerospace Inc.: Amendment 39-22774; Docket 
No. FAA-2023-1891; Project Identifier AD-2023-00612-R.

(a) Effective Date

    This airworthiness directive (AD) is effective August 26, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Centerpointe Aerospace Inc. Model S-58BT, 
S-58DT, S-58ET, S-58FT, S-58HT, and S-58JT helicopters, certificated 
in any category.

(d) Subject

    Joint Aircraft System Component (JASC) Code: 6300, Main Rotor 
Drive System.

(e) Unsafe Condition

    This AD was prompted by the discovery of a fatigue crack on the 
angle gearbox mount (AGBM). The FAA is issuing this AD to detect 
fatigue cracking of the AGBM. The unsafe condition, if not 
addressed, could lead to loss of the angle gearbox, resulting in 
loss of main 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

    (1) Within 250 hours time-in-service (TIS) after the effective 
date of this AD, and thereafter at intervals not to exceed 250 hours 
TIS, perform a fluorescent penetrant inspection (FPI) to inspect for 
any crack on the AGBM in the eight areas depicted in the 
Accomplishment Instructions, Figures 1A and 1B, of Centerpointe 
Aerospace Service Bulletin No. 58B75, dated April 26, 2023. This FPI 
must be accomplished by a Level II or Level III inspector certified 
in the FAA-acceptable standards for nondestructive inspection 
personnel.
    (2) If there is any crack, before further flight, remove the 
AGBM from service.

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Central 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 certification office, send it to the 
attention of the person identified in paragraph (i) of this AD and 
email 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

    For more information about this AD, contact Jacob Fitch, 
Aviation Safety Engineer, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 
76177; phone: (817) 222-4130; email: [email protected].

(j) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) 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) Centerpointe Aerospace Service Bulletin No. 58B75, dated 
April 26, 2023.
    (ii) [Reserved]
    (3) For Centerpointe Aerospace service information identified in 
this AD, contact Centerpointe Aerospace Inc., 279 Blackland Road, 
Fate, TX 75189; phone: (972) 636-9601; email: 
[email protected]; website: californiahelicopter.com.
    (4) You may view this service information at the FAA, Office of 
the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 
6N-321, 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 July 16, 2024.
James D. Foltz,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-16012 Filed 7-19-24; 8:45 am]
BILLING CODE 4910-13-P