DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-1006; Project Identifier 2019-CE-047-AD; Amendment
39-21855; AD 2021-25-11]
RIN 2120-AA64

Airworthiness Directives; Piper Aircraft, Inc. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 78-02-03,
which applied to all Piper Aircraft, Inc. (Piper) Model PA-23-250
airplanes. AD 78-02-03 required repetitively inspecting the stabilator
tip tube and weight assemblies for cracks, inspecting for missing
rivets and screws, replacing the forward rib/horn assemblies, and
reinforcing the mounting. Since AD 78-02-03 was issued, Piper developed
a newly-designed stabilator, which is not subject to the unsafe
condition, and revised its service information. This AD retains the
actions of AD 78-02-03, but reduces the applicability and requires the
actions in the revised service information. The FAA is issuing this AD
to address the unsafe condition on these products.

DATES: This AD is effective January 25, 2022.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of January 25,
2022.

ADDRESSES: For service information identified in this final rule,
contact Piper Aircraft, Inc., 2926 Piper Drive, Vero Beach, FL 32960;
phone: (772) 299-2141; website: https://www.piper.com/. You may view
this service information 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 https://www.regulations.gov by
searching for and locating Docket No. FAA-2020-1006.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2020-1006; 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 street address for Docket
Operations is listed above.

FOR FURTHER INFORMATION CONTACT: John Marshall, Aviation Safety
Engineer, Atlanta ACO Branch, FAA, 1701 Columbia Avenue, College Park,
GA 30337; phone: (404) 474-5524; fax: (404) 474-5605; email:
john.r.marshall@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by superseding AD 78-02-03 [Reg. Docket No. 77-EA-81,
Amendment 39-3128] (43 FR 3079, January 23, 1978) (AD 78-02-03). AD 78-
02-03 applied to all Piper Model PA-23-250 airplanes and required
repetitively inspecting both the stabilator tip tube and weight
assemblies for cracks. For different groups of serial-numbered
airplanes, AD 78-02-03 required a one-time inspection of the stabilator
tip ribs for missing rivets and screws, replacement of the forward rib/
horn assemblies, and reinforcement of the mounting. The repetitive
inspections in AD 78-02-03 for all serial-numbered airplanes had no
terminating action and were required regardless of any corrective
actions performed.
The NPRM published in the Federal Register on September 16, 2021
(86 FR 51636). The NPRM was prompted by Piper developing a newly-
designed stabilator, which is not subject to the unsafe condition, and
revising its service information. The FAA determined the applicability
of AD 78-02-03 should be revised to exclude airplanes beginning with
serial number 27-7954122, which were manufactured with the stabilator
design change. In the NPRM, the FAA proposed to retain all of the
requirements of AD 78-02-03 but reduce the applicability and update
some of the service information that would be required for compliance.
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. This AD is
adopted as proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

The FAA reviewed the following service documents required for
compliance with this AD:
Piper Service Bulletin (SB) No. 547, dated March 1, 1977,
which contains instructions for inspecting the stabilator tip rib;
Piper SB No. 569, dated August 24, 1977, which contains
information for replacing the stabilator tab horn;
Piper Service Letter No. 807A, dated September 8, 1977,
which contains information for installing the stabilator outboard nose
rib; and
Piper SB No. 540B, February 9, 2021, which contains
instructions for inspecting the stabilator tip tube and weight assembly
and addressing any cracks found.
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.

Other Related Service Information

The FAA reviewed the following documents for information related to
this AD:
Piper SB 540, which contains instructions for inspecting
and reinforcing the stabilator tip tube and weight assembly; and
Piper Aztec Service Manual, Part Number 753-564, dated
January 1, 2009. Paragraphs 4-65 through 4-67 of this manual contain
procedures for checking control surface balance.

Differences Between This AD and the Service Information

Piper SB 540B specifies contacting Piper for repair instructions.
This AD requires contacting the FAA for an approved repair method
instead.

Costs of Compliance

The FAA estimates that this AD affects 625 airplanes of U.S.
registry.
The FAA estimates the following costs to comply with this AD:

Estimated Costs

The FAA estimates the following costs to do any necessary repairs
or replacements that will be required based on the results of the
inspection. The FAA has no way of determining the number of airplanes
that might need these repairs or replacements:

On-Condition Costs

For airplanes with kit P/N 763 987, the cost to repair cracking may
vary significantly from airplane to airplane, and therefore the FAA has
no way of determining an estimated cost.

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:

a. Removing Airworthiness Directive 78-02-03 [Reg. Docket No. 77-EA-81,
Amendment 39-3128] (43 FR 3079, January 23, 1978); and

b. Adding the following new airworthiness directive: