DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0819; Project Identifier 2019-CE-027-AD; Amendment
39-21500; AD 2021-08-06]
RIN 2120-AA64

Airworthiness Directives; Textron Aviation Inc. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 97-06-10
for certain Raytheon Aircraft Company (type certificate now held by
Textron Aviation Inc. (Textron)) Model 76 airplanes. AD 97-06-10
required repetitively inspecting the main landing gear (MLG) ``A''
frame assemblies for cracks and replacing any cracked assembly. Since
the FAA issued AD 97-06-10, the replacement parts have also experienced
failure due to cracking. This AD requires magnetic particle inspections
of the MLG ``A'' frame assemblies for cracks and replacement of the
affected parts if necessary. The FAA is issuing this AD to address the
unsafe condition on these products.

DATES: This AD is effective May 25, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of May 25,
2021.

ADDRESSES: For the Beechcraft service information identified in this
final rule, contact Textron Aviation Customer Service, P.O. Box 7706,
Wichita, KS 67277; phone: (316) 517-5800; email:
customercare@txtav.com; website: https://txtav.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 (816) 329-4148.
It is also available at https://www.regulations.gov by searching for
and locating Docket No. FAA-2020-0819.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2020-0819; 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.

FOR FURTHER INFORMATION CONTACT: Brian Adamson, Aviation Safety
Engineer, Wichita ACO Branch, FAA, 1801 Airport Road, Room 100,
Wichita, KS 67209; phone: (316) 946-4193; fax: (316) 946-4107; email:
brian.adamson@faa.gov or Wichita-COS@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 97-06-10, Amendment 39-9967 (62 FR 12949,
March 19, 1997) (AD 97-06-10). AD 97-06-10 applied to Raytheon Aircraft
Company (type certificate now held by Textron) Model 76 airplanes,
serial numbers ME-1 through ME-437 that do not have both a part number
(P/N) 105-810023-75 (left) and P/N 105-810023-76 (right) MLG ``A''
frame assembly installed. The NPRM published in the Federal Register on
December 14, 2020 (85 FR 80693).
AD 97-06-10 required repetitive visual and dye penetrant
inspections of the MLG ``A'' frame assemblies for cracks and
replacement of any assembly found cracked. AD 97-06-10 did not apply to
Model 76 airplanes with an improved design MLG ``A'' frame assembly (P/
N 105-810023-75 and P/N 105-810023-76) installed on both the left and
right MLG. The FAA issued AD 97-06-10 to prevent MLG failure because of
a cracked ``A'' frame assembly, which could result in loss of control
of the airplane during landing.
The NPRM was prompted by reports of P/N 105-810023-75 and P/N 105-
810023-76 ``A'' frame assemblies failing due to fatigue cracking,
resulting in damage to the propeller and outboard wing area. The FAA
determined that the visual and dye penetrant inspections were not
adequately detecting cracks in the MLG ``A'' frame assemblies, because
some of the failed parts had been subjected to visual and dye penetrant
inspections within 100 hours before the failure.
In the NPRM, the FAA proposed to require repetitive magnetic
particle inspections, which provide quicker results (after testing
setup) with improved accuracy. Also, the NPRM reflected that the type
certificate for the Model 76 airplane had been transferred from
Raytheon to Textron, and that Textron designed new replacement parts,
P/Ns 105-810023-0083 (left) and 105-810023-0084 (right), that were not
subject to the proposed repetitive magnetic particle inspections.
However, the newly designed MLG assemblies are still subject to the
repetitive inspections specified in the maintenance manual.

Discussion of Final Airworthiness Directive

Comments

The FAA received two comments from an anonymous commenter. The
following presents the comments received on the NPRM and the FAA's
response to each comment.
Request Regarding New Part Numbers
One commenter stated that a Model 76 with the new A-frames had a
main gear collapse on landing in August 2020. The commenter questioned
whether the new A-frames are also subject to failure.
The FAA disagrees with this comment. The commenter did not provide
any data to show that the Textron Model 76 accident airplane, whose
landing gear failed during landing or taxi conditions, had the new A-
frames installed. Neither the FAA nor Textron have any data indicating
that P/Ns 105-8100023-0083 and 105-810023-0084 A-frames were installed
on the accident airplane. In addition, Textron has not received any
reports of failed P/Ns 105-8100023-0083 and 105-810023-0084 A-frames.
Request Regarding Estimated Cost
The commenter requested the FAA find an alternative solution that
is more affordable for operators. The commenter stated that each
magnetic particle inspection would be costly because the inspection
involves frame removal. The commenter also included documentation
showing that the cost of an A-frame from Textron is over $8,000 and,
with labor costs of $2,200 for installation, owners will spend over
$18,500 to replace the A-frames.
The FAA partially agrees with this comment. The FAA has updated the
estimated costs to reflect the costs provided by the commenter to
replace the parts. The FAA disagrees with the commenter's estimate of
labor costs to replace an A-frame, because the labor to install a
replacement part is included with the labor costs for the inspection.
The FAA has added language to the on-condition costs to clarify how the
FAA estimated the cost to replace each part. The FAA also acknowledges
that the general obligation of the operator to maintain its aircraft in
an airworthy condition is vital, but sometimes expensive.

Conclusion

The FAA reviewed the relevant data, considered any comments
received, and determined that air safety requires adopting the 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 Beechcraft Mandatory Service Bulletin SB 32-4156,
dated May 3, 2019. This service information specifies procedures for a
repetitive magnetic particle inspection for fatigue cracks adjacent to
the gussets for the torque arm of each MLG ``A'' frame and destroying
the assembly if cracks are found. The service information also
specifies procedures for installing a replacement assembly or re-
installing an assembly when no cracks are 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 ADDRESSES.

Costs of Compliance

The FAA estimates that this AD affects 437 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
replacements that would be required based on the results of the
inspection. The agency has no way of determining the number of aircraft
that might need these replacements:

On-Condition Costs

* No additional labor cost since re-installation labor is included with the inspection
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

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

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 97-06-10, Amendment 39-9967 (62 FR
12949, March 19, 1997); and

b. Adding the following new airworthiness directive: