DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2005; Project Identifier AD-2022-01523-A]
RIN 2120-AA64

Airworthiness Directives; WACO Classic Aircraft Corporation Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain WACO Classic Aircraft Corporation Model 2T-1A-2 airplanes.
This proposed AD was prompted by reports of multiple types of cracks at
the leading edge former ribs and trailing edge former ribs in the upper
wing center section. This proposed AD would require installing maneuver
restriction placards in the front and rear cockpits, inspecting the
leading and trailing edge former ribs for cracking, replacing any
cracked ribs, modifying the upper wing center section assembly, and
removing the maneuver restriction placards after completing the
modification. The FAA is proposing this AD to address the unsafe
condition on these products.

DATES: The FAA must receive comments on this proposed AD by December
11, 2023.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.
Fax: (202) 493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-2005; 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 NPRM, any comments received, and other
information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
For service information identified in this NPRM, contact
WACO Classic Aircraft Corporation, 15955 South Airport Road, Battle
Creek, MI 49015; phone: (269) 565-1000; email: hello@wacoaircraft.com.;
website: wacoaircraft.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.

FOR FURTHER INFORMATION CONTACT: Tim Eichor, Aviation Safety Engineer,
FAA, 1801 S Airport Road, Wichita, KS 67209; phone: (847) 294-7141;
email: tim.d.eichor@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2023-2005; Project Identifier
AD-2022-01523-A'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this NPRM.

Confidential Business Information

CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to Tim
Eichor, Aviation Safety Engineer, FAA, 1801 S Airport Road, Wichita, KS
67209. Any commentary that the FAA receives which is not specifically
designated as CBI will be placed in the public docket for this
rulemaking.

Background

The FAA received reports of multiple types of cracks after low
flight hours on WACO Classic Aircraft Corporation Model 2T-1A-2
airplanes. The cracks were approximately 1 to 1.5 inches long and
located in the leading edge former ribs and trailing edge former ribs
in the upper wing center section, along the top flange where the ribs
attach to the spar. Due to the cracking, the fabric support channels
have come close to separating from the trailing edge former ribs. When
fabric support channels detach from a rib, they would still be attached
to the fabric, but the upper center wing airfoil may not maintain its
shape due to the fabric support channels being pulled up by aerodynamic
loads, which could lead to unexpected and unknown flight
characteristics. The type certificate holder determined that this
unsafe condition affects airplane serial numbers 1200 and subsequent
with the upper wing center section assembly 30116-100 configuration.
This condition, if not addressed, could result in reduced
structural integrity of the airplane and the reduced ability of the
flightcrew to maintain the safe flight and landing of the airplane.

FAA's Determination

The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type design.

Related Service Information Under 1 CFR Part 51

The FAA reviewed WACO Great Lakes 2T-1A-2 Service Bulletin GL-
SB0002, Revision NR, dated July 6, 2023 (WACO SB 2T-1A-2, Revision NR).
This service information specifies procedures for inspecting the
leading edge former ribs and trailing edge former ribs in the upper
wing center section for cracking, replacing any cracked ribs, and
modifying the upper wing center section assembly by installing new
fabric support channels, saddles, and brackets. Modifying the upper
wing center section assembly changes the configuration from the 30116-
100 upper wing center section assembly configuration to the 30116-104
upper wing center section assembly configuration. 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 ADDRESSES.

Proposed AD Requirements in This NPRM

This proposed AD would require installing maneuver restriction
placards in the front and rear cockpits, inspecting the leading and
trailing edge former ribs for cracking, replacing any cracked rib,
modifying the upper wing center section assembly, and removing the
maneuver restriction placards after completing the modification.

Difference Between This Proposed AD and the Service Information

Although section B of the Accomplishment Instructions in WACO SB
2T-1A-2, Revision NR, specifies to record the locations of all
identified cracks found on the leading edge former ribs and the
trailing edge former ribs and share this information with WACO Aircraft,
this proposed AD would not require those actions.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 19 airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
AD:

Estimated Costs

The FAA estimates the following costs to do any necessary rib
replacement that would be required based on the results of the proposed
inspection. The agency has no way of determining the number of
airplanes that might need this replacement:

On-Condition Costs

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 determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska and
(3) Would 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 Proposed Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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: