[Federal Register Volume 89, Number 2 (Wednesday, January 3, 2024)]
[Rules and Regulations]
[Pages 237-239]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-28877]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2005; Project Identifier AD-2022-01523-A; 
Amendment 39-22646; AD 2023-26-03]
RIN 2120-AA64


Airworthiness Directives; WACO Classic Aircraft Corporation 
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain WACO Classic Aircraft Corporation Model 2T-1A-2 airplanes. This 
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 AD requires 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 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective February 7, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of February 7, 
2024.

ADDRESSES: 
    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 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 service information identified in this final rule, 
contact WACO Classic Aircraft Corporation, 15955 South Airport Road, 
Battle Creek, MI 49015; phone: (269) 565-1000; email: 
wacoaircraft.com">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

[[Page 238]]

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-2023-2005.

FOR FURTHER INFORMATION CONTACT: Tim Eichor, Aviation Safety Engineer, 
FAA, 1801 S Airport Road, Wichita, KS 67209; phone: (847) 294-7141; 
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 certain WACO Classic 
Aircraft Corporation Model 2T-1A-2 airplanes. The NPRM published in the 
Federal Register on October 27, 2023 (88 FR 73780). The NPRM was 
prompted by 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. In the NPRM, the FAA proposed 
to 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 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 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 the ADDRESSES section.

Difference Between This 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 AD does not require those actions.

Costs of Compliance

    The FAA estimates that this AD affects 19 airplanes of U.S. 
registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                       Cost on
                Action                          Labor cost             Parts cost       Cost per         U.S.
                                                                                         product      operators
----------------------------------------------------------------------------------------------------------------
Maneuver restriction placard           1 work-hour x $85 per hour =             $10             $95       $1,805
 installation/removal.                  $85.
Rib inspection.......................  4 work-hours x $85 per hour                0             340        6,460
                                        = $340.
Upper wing center assembly             185 work-hours x $85 per               4,063          19,788      375,972
 modification.                          hour = $15,725.
----------------------------------------------------------------------------------------------------------------

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

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
               Action                         Labor cost                Parts cost           Cost per  product
----------------------------------------------------------------------------------------------------------------
Rib replacement (8 ribs)...........  16 work-hours x $85 per      $1,032 (8 ribs).......  $2,392 (8 ribs).
                                      hour = $1,360 (8 ribs).
----------------------------------------------------------------------------------------------------------------

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

[[Page 239]]

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

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:

2023-26-03 WACO Classic Aircraft Corporation: Amendment 39-22646; 
Docket No. FAA-2023-2005; Project Identifier AD-2022-01523-A.

(a) Effective Date

    This airworthiness directive (AD) is effective February 7, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to WACO Classic Aircraft Corporation Model 2T-
1A-2 airplanes, serial numbers 1200 and subsequent with the 30116-
100 upper wing center section assembly configuration, certificated 
in any category.

(d) Subject

    Joint Aircraft System Component (JASC) Code 5712, Wing, Rib/
Bulkhead.

(e) Unsafe Condition

    This AD was prompted by reports of multiple cracks at 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 after low flight hours. The FAA is issuing this AD to 
detect and correct cracks in the leading and trailing edge former 
ribs in the upper wing center section. The unsafe 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.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) Within 30 days after the effective date of this AD, insert 
maneuver restriction placards on the instrument panel of the front 
and rear cockpits, and next to the operating placard in the rear 
cockpit, stating ``NO AEROBATIC MANEUVERS ALLOWED.''
    (2) Within 100 hours time-in-service (TIS) or within 12 months 
after the effective date of this AD, whichever occurs first, 
accomplish the following:
    (i) Inspect the leading edge former ribs and trailing edge 
former ribs in the upper wing center section for cracking in 
accordance with section B and before further flight, replace any 
cracked rib in accordance with section C of the Accomplishment 
Instructions in WACO Great Lakes 2T-1A-2 Service Bulletin GL-SB0002, 
Revision NR, dated July 6, 2023 (WACO SB 2T-1A-2, Revision NR). 
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 AD does not require those actions.
    (ii) Modify the center section to the 30116-104 upper wing 
center section assembly configuration in accordance with section C 
of the Accomplishment Instructions in WACO SB 2T-1A-2, Revision NR.
    (3) After replacing all cracked ribs and modifying the center 
section to the 30116-104 upper wing center section assembly 
configuration, aerobatic maneuvers can resume and the ``NO AEROBATIC 
MANEUVERS ALLOWED'' maneuver restriction placards can be removed 
from the front and rear cockpits.

(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 Central Certification Branch, send it 
to the attention of the person identified in paragraph (i) of this 
AD.
    (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 Tim Eichor, Aviation 
Safety Engineer, FAA, 1801 S Airport Road, Wichita, KS 67209; phone: 
(847) 294-7141; 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) WACO Great Lakes 2T-1A-2 Service Bulletin GL-SB0002, 
Revision NR, dated July 6, 2023.
    (ii) [Reserved]
    (3) For service information identified in this AD, contact WACO 
Classic Aircraft Corporation, 15955 South Airport Road, Battle 
Creek, MI 49015; phone: (269) 565-1000; email: 
wacoaircraft.com">hello@wacoaircraft.com.; website: wacoaircraft.com.
    (4) 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.
    (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 December 21, 2023.
Caitlin Locke,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2023-28877 Filed 1-2-24; 8:45 am]
BILLING CODE 4910-13-P