[Federal Register Volume 90, Number 144 (Wednesday, July 30, 2025)]
[Rules and Regulations]
[Pages 35831-35835]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-14390]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-0013; Project Identifier MCAI-2024-00375-A;
Amendment 39-23097; AD 2025-15-10]
RIN 2120-AA64
Airworthiness Directives; Piaggio Aviation S.p.A. Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2023-25-
03, which applied to certain Piaggio Aviation S.p.A. (Piaggio) Model P-
180 airplanes. AD 2023-25-03 required a one-time detailed inspection of
the horizontal stabilizer (HS) central box for corrosion; an assessment
of the corrosion level; and depending on the determination, repetitive
detailed inspections of the HS central box for corrosion and the
internal composite structure for surface cracks, distortion, and
damage; and repair or replacement of the HS assembly. Repair or
replacement of the HS assembly was terminating action for the
repetitive inspections. Since the FAA issued AD 2023-25-03, it was
determined that AD 2023-25-03 imposed an unintended restriction that is
not in the mandatory continuing airworthiness information (MCAI). This
AD retains certain actions of AD-2023-25-03 and removes the unintended
restriction. The FAA is
[[Page 35832]]
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective September 3, 2025.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of February 2,
2024 (88 FR 90085, December 29, 2023).
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2025-0013; 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, the MCAI, 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 Piaggio material identified in this AD, contact
Piaggio Aviation S.p.A., P180 Customer Support, via Pionieri e Aviatori
d'Italia, snc--16154 Genoa, Italy; phone: +39 331 679 74 93; email:
[email protected].
You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 901 Locust, Kansas City,
MO 64106. 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-2025-0013.
FOR FURTHER INFORMATION CONTACT: William McCully, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (404) 474-5548; email: [email protected].
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2023-25-03, Amendment 39-22630 (88 FR
90085, December 29, 2023) (AD 2023-25-03). AD 2023-25-03 applied to
certain Piaggio Model P-180 airplanes.
AD 2023-25-03 was prompted by AD 2023-0007, dated January 13, 2023
(EASA AD 2023-0007) (also referred to as the MCAI) issued by the
European Union Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Union. The MCAI states that
an occurrence of corrosion was found inside the HS central box of a
Piaggio Model P-180 airplane during scheduled maintenance. A subsequent
investigation and inspection of 16 other Piaggio Model P-180 airplanes
of various configurations and ages revealed that corrosion of differing
levels of severity was found on various aluminum alloy reinforcements
in the HS central box of all the inspected airplanes. The MCAI also
states that this corrosion was caused by the formation of a humid
environment inside the HS central box, from water ingress and/or
condensation. Further investigation revealed that airplanes left in
prolonged inactivity or parked outside are more prone to develop
corrosion damage.
AD 2023-25-03 required a one-time detailed inspection of the HS
central box for corrosion; an assessment of the corrosion level; and
depending on the determination, repetitive detailed inspections of the
HS central box for corrosion and the internal composite structure for
surface cracks, distortion, and damage; and repair or replacement of
the HS assembly. Repair or replacement of the HS assembly was
terminating action for the repetitive inspections. The FAA issued AD
2023-25-03 to address corrosion on various aluminum alloy
reinforcements in the HS central box caused by a humid environment
inside the box from water ingress and/or condensation. Since the FAA
issued AD 2023-25-03, it was determined that a portion of paragraph
(g)(4)(ii) of that AD included an unintended requirement to replace or
repair the HS assembly after 660 hours time-in-service (TIS) or 13
months, whichever occurs first, following a finding of level 2
corrosion.
The NPRM published in the Federal Register on January 30, 2025 (90
FR 8507). In the NPRM, the FAA proposed to retain certain actions of
AD-2023-25-03 and remove the unintended restriction. The FAA is issuing
this AD to address corrosion on the various aluminum alloy
reinforcements in the HS central box caused by a humid environment
inside the box from water ingress and/or condensation. The unsafe
condition, if not addressed, could result in reduced structural
integrity of the HS and loss of control of the airplane.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2025-0013.
Discussion of Final Airworthiness Directive
Comments
The FAA received one comment from an individual commenter. The
following presents the comment received on the NPRM and the FAA's
response to that comment.
Request To Allow Nondestructive Testing (NDT) Options
The commenter noted that in the NPRM the proposed cost estimate for
repetitive inspections is based on traditional physical inspections,
which require extensive airplane downtime. The commenter stated that
allowing NDT methods, such as eddy current or ultrasonic inspections,
provides a viable alternative to the traditional physical inspection
methods specified in the proposed AD, that could significantly reduce
the amount of labor hours while maintaining safety standards. The
commenter mentioned that in the FAA's Aviation Maintenance Technical
Handbook--General (FAA-H-8083-30B) 2023, NDT methods allow for the
detection of subsurface corrosion without requiring component
disassembly, so they are more efficient for routine inspections. The
commenter stated that allowing NDT as an alternative compliance method
would ensure continued airworthiness without imposing unnecessary
financial burdens on operators. The FAA infers that the commenter
requested that the proposed AD be revised to include NDT methods.
The FAA agrees with the commenter's statements about NDT methods
allowing for the detection of subsurface corrosion without requiring
component disassembly and that NDT would not impose unnecessary
financial burdens upon operators. A borescope inspection is considered
an NDT method. The costs of this AD account for borescope inspections.
The FAA acknowledges that eddy current and ultrasound inspection
methods are generally effective to detect subsurface damage in single
or stacked layers of material because these methods can reveal damage
in hidden or difficult to access areas. For this AD, a borescope
inspection is considered the least invasive and has been determined to
be the most effective in areas such as the HS central box. However, an
operator may apply for an alternative method of compliance (AMOC) in
accordance with paragraph (i) of this AD, along with substantiation
data to show that eddy current and ultrasound methods would provide an
acceptable level of safety.
The FAA has not changed this AD as a result of this comment.
Conclusion
These products have been approved by the aviation authority of
another country and are approved for operation in the United States.
Pursuant to the FAA's bilateral agreement with this State of Design
Authority, it has notified the FAA of the unsafe condition
[[Page 35833]]
described in the MCAI referenced above. 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. This AD is
adopted as proposed in the NPRM.
Material Incorporated by Reference Under 1 CFR Part 51
This AD requires Piaggio Aerospace Service Bulletin 80-0489,
Revision 2, dated November 30, 2022, which the Director of the Federal
Register approved for incorporation by reference as of February 2, 2024
(88 FR 90085, December 29, 2023).
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.
Differences Between This AD and the Referenced Material
The Referenced Material requires contacting the manufacturer for a
determination of the corrosion level if any corrosion is found during
the initial inspection of the HS central box, and if it is determined
that level 2 or 3 corrosion is present, having the manufacturer provide
the threshold and intervals for doing repetitive inspections of the HS
central box. This AD requires contacting either the FAA, EASA, or
Piaggio's EASA Design Organization Approval (DOA). If approved by the
DOA, the approval must include the DOA-authorized signature.
Although Piaggio Aerospace Service Bulletin 80-0489, Revision 2,
dated November 30, 2022, specifies to record the image of the location
of corroded areas, this AD does not require that action.
Costs of Compliance
The FAA estimates that this AD affects 102 airplanes of U.S.
registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Initial inspection of HS central box for 6 work-hours x $85 per hour $0 $510 $52,020
corrosion. = $510.
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On-Condition Costs
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Action Labor cost Parts cost Cost per product
----------------------------------------------------------------------------------------------------------------
Repetitive inspections of HS 6 work-hours x $85 $0 $510, per inspection cycle.
central box for corrosion. per hour = $510,
per inspection
cycle.
Repetitive inspections for 6 work-hours x $85 0 $510, per inspection cycle.
surface cracks, distortion, and per hour = $510,
damage. per inspection
cycle.
Replace HS assembly.............. 10 work-hours x $85 150,000 $150,850.
per hour = $850.
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The repair of the HS assembly that may be required as a result of
any inspection could vary significantly from airplane to airplane. The
FAA has no data to determine the costs to accomplish the repair or the
number of airplanes that may require the repair.
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 has determined that 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:
0
a. Removing Airworthiness Directive 2023-25-03, Amendment 39-22630 (88
FR 90085, December 29, 2023); and
0
b. Adding the following new airworthiness directive:
2025-15-10 Piaggio Aviation S.p.A.: Amendment 39-23097; Docket No.
FAA-2025-0013; Project Identifier MCAI-2024-00375-A.
(a) Effective Date
This airworthiness directive (AD) is effective September 3,
2025.
[[Page 35834]]
(b) Affected ADs
This AD replaces AD 2023-25-03, Amendment 39-22630 (88 FR 90085,
December 29, 2023).
(c) Applicability
This AD applies to Piaggio Aviation S.p.A. Model P-180
airplanes, serial numbers (S/Ns) 1002, 1004 through 1234 inclusive,
3001 through 3012 inclusive, and 3016, certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 5510, Horizontal
Stabilizer Structure.
(e) Unsafe Condition
This AD was prompted by a report of corrosion on the various
aluminum alloy reinforcements in the horizontal stabilizer (HS)
central box caused by a humid environment inside the box from water
ingress and/or condensation. The FAA is issuing this AD to address
this condition. The unsafe condition, if not addressed, could result
in reduced structural integrity of the HS and loss of control of the
airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) Within the applicable compliance time specified in table 1
to paragraph (g)(1) of this AD, do a detailed inspection of the HS
central box for corrosion, in accordance with step (8), of Part A,
of the Accomplishment Instructions in Piaggio Aerospace Service
Bulletin 80-0489, Revision 2, dated November 30, 2022 (Piaggio SB
80-0489, Revision 2), except you are not required to record any
images.
Table 1 to Paragraph (g)(1)--HS Central Box One Time Inspection
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Compliance time (hours Time-in-
Service (TIS) or calendar time,
P-180 serial No. whichever occurs first after
February 2, 2024 (the effective date
of AD 2023-25-03))
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1002; and 1034 through 3016 Within 220 hours TIS or 13 months
inclusive. after February 2, 2024 (the
effective date of AD 2023-25-03).
1004 through 1033 inclusive....... Within 320 hours TIS or 13 months
after February 2, 2024 (the
effective date of AD 2023-25-03).
------------------------------------------------------------------------
(2) If, during the inspection required by paragraph (g)(1) of
this AD, any corrosion is detected, before next flight, contact
either the Manager, International Validation Branch, FAA; European
Union Aviation Safety Agency (EASA); or Piaggio's EASA Design
Organization Approval (DOA), for an assessment of the corrosion
level (level 1, 2, or 3).
Note 1 to paragraph (g)(2): Appendix 1, Inspection Results Form,
in Piaggio SB 80-0489, Revision 2, may be used when contacting the
FAA, EASA, or Piaggio's EASA DOA.
(3) If level 1 corrosion is found during the inspection required
by paragraph (g)(1) of this AD, no further action is required by
this AD.
(4) If level 2 corrosion is found during the inspection required
by paragraph (g)(1) of this AD, do the action in either paragraph
(g)(4)(i) or (ii) of this AD.
(i) Before further flight, replace the HS assembly or repair the
HS assembly in accordance with instructions from either the Manager,
International Validation Branch, FAA; EASA; or Piaggio's EASA DOA.
If approved by the DOA, the approval must include the DOA-authorized
signature.
(ii) Within 400 hours TIS or 12 months, whichever occurs first
after the inspection required by paragraph (g)(1) of this AD, and
thereafter at intervals not to exceed 400 hours TIS or 12 months,
whichever occurs first after the most recent inspection, repeat the
inspection required by paragraph (g)(1) of this AD. In addition,
inspect the internal composite structure of the HS central box for
surface cracks, distortion, and damage. After each repetitive
inspection, before further flight, assess the inspection findings as
required by paragraph (g)(2) of this AD. If it is determined that
the level 2 corrosion has worsened since the last inspection; or if
any surface cracks, distortion, or damage is found during any
inspection; before further flight, replace the HS assembly or repair
the HS assembly in accordance with instructions from either the
Manager, International Validation Branch, FAA; EASA; or Piaggio's
EASA DOA. If approved by the DOA, the approval must include the DOA-
authorized signature. These inspections must be repeated at
intervals not to exceed 400 hours TIS or 12 months, whichever occurs
first after the most recent inspection.
(5) If level 3 corrosion is found during the inspection required
by paragraph (g)(1) of this AD, do the actions required by paragraph
(g)(5)(i) or (ii) of this AD.
(i) Before further flight after the inspection required by
paragraph (g)(1) of this AD, replace the HS assembly or repair the
HS assembly in accordance with instructions from either the Manager,
International Validation Branch, FAA; EASA; or Piaggio's EASA DOA.
If approved by the DOA, the approval must include the DOA-authorized
signature.
(ii) Within 200 hours TIS or 6 months, whichever occurs first
after the inspection required by paragraph (g)(1) of this AD, and
thereafter at intervals not to exceed 200 hours TIS or 6 months,
whichever occurs first after the most recent inspection, repeat the
inspection required by paragraph (g)(1) of this AD. In addition,
inspect the internal composite structure of the HS central box for
surface cracks, distortion, and damage. After each repetitive
inspection, before further flight, assess the inspection findings as
required by paragraph (g)(2) of this AD. If it is determined that
the level 3 corrosion has worsened since the last inspection; or if
any surface cracks, distortion, or damage is found; before further
flight, replace the HS assembly or repair the HS assembly in
accordance with instructions from either the Manager, International
Validation Branch, FAA; EASA; or Piaggio's EASA DOA. If approved by
the DOA, the approval must include the DOA-authorized signature.
These inspections must be repeated at intervals not to exceed 200
hours TIS or 6 months, whichever occurs first after the most recent
inspection, until a maximum of 660 hours TIS or 13 months, whichever
occurs first after the inspection required by paragraph (g)(1) of
this AD, at which time the HS assembly must be repaired or replaced.
(6) Repair or replacement of the HS assembly is terminating
action for the repetitive inspections required by paragraphs
(g)(4)(ii) and (g)(5)(ii) of this AD.
(h) Credit for Previous Actions
You may take credit for the actions required by paragraphs
(g)(1) through (5) of this AD if you performed those actions before
February 2, 2024 (the effective date of AD 2023-25-03) using Piaggio
Aerospace Service Bulletin 80-0489, Revision 1, dated May 13, 2022.
(i) Alternative Methods of Compliance (AMOCs)
The Manager, International Validation 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 International Validation Branch, mail
it to the address identified in paragraph (j) of this AD or email
to: [email protected]. If mailing information, also submit information by
email. 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) Additional Information
For more information about this AD, contact William McCully,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: (404) 474-5548; 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.
[[Page 35835]]
(2) You must use this material as applicable to do the actions
required by this AD, unless the AD specifies otherwise.
(3) The following material was approved for IBR on February 2,
2024 (88 FR 90085, December 29, 2023).
(i) Piaggio Aerospace Service Bulletin 80-0489, Revision 2,
dated November 30, 2022.
(ii) [Reserved]
(4) For Piaggio material identified in this AD, contact Piaggio
Aviation S.p.A., P180 Customer Support, via Pionieri e Aviatori
d'Italia, snc--16154 Genoa, Italy; phone: +39 331 679 74 93; email:
[email protected].
(5) You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 901 Locust, Kansas
City, MO 64106. For information on the availability of this material
at the FAA, call (817) 222-5110.
(6) 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 25, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2025-14390 Filed 7-29-25; 8:45 am]
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