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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:
Operations@avnresources.com; 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: jacob.fitch@faa.gov.
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
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.
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
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]
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive:
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