FR Doc 07-1106

[Federal Register: March 12, 2007 (Volume 72, Number 47)]
[Rules and Regulations]
[Page 10909-10918]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr12mr07-4]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25105; Directorate Identifier 2006-CE-33-AD;
Amendment 39-14982; AD 2007-06-01]
RIN 2120-AA64

Airworthiness Directives; Raytheon Aircraft Company Beech Models
45 (YT-34), A45 (T-34A, B-45), and D45 (T-34B) Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) that
supersedes AD 62-24-01, which applies to all Raytheon Aircraft Company
(RAC) Beech Models 45 (YT-34), A45 (T-34A, B45), and D45 (T-34B)
airplanes. AD 62-24-01 currently requires you to repetitively inspect,
using the dye penetrant method, the front and rear horizontal
stabilizer spars for cracks and replace any cracked stabilizer. Since
we issued AD 62-24-01, we determined that using the dye penetrant
inspection method may not detect cracks before the crack grows to a
critical length and causes failure of the horizontal stabilizer spars.
Therefore, we are requiring the surface eddy current inspection method
to detect cracks in the horizontal stabilizer spars. Consequently, this
AD retains the actions required in AD 62-24-01 and changes the required
inspection method from dye penetrant to surface eddy current. We are
issuing this AD to prevent failure of the front and/or rear horizontal
stabilizer spars caused by fatigue cracks. This failure could result in
stabilizer separation and loss of control of the airplane.

DATES: This AD becomes effective on April 16, 2007.

ADDRESSES: To view the AD docket, go to the Docket Management Facility,
U.S. Department of Transportation, 400 Seventh Street, SW., Nassif
Building, Room PL-401, Washington, DC 20590-001 or on the Internet at
http://dms.dot.gov. The docket number is FAA-2006-25105; Directorate

Identifier 2006-CE-33-AD.

FOR FURTHER INFORMATION CONTACT: T.N. Baktha, Aerospace Engineer, FAA,
Wichita Aircraft Certification Office, 1801 Airport Road, Mid-Continent
Airport, Wichita, Kansas 67209; telephone: (316) 946-4155; fax: (316)
946-4107.

SUPPLEMENTARY INFORMATION:

[[Page 10910]]

Discussion

On July 24, 2006, we issued a proposal to amend part 39 of the
Federal Aviation Regulations (14 CFR part 39) to include an AD that
would apply to all RAC Beech Models 45 (YT-34), A45 (T-34A, B45), and
D45 (T-34B) airplanes. That proposal was published in the Federal
Register as a notice of proposed rulemaking (NPRM) on July 31, 2006 (71
FR 43075). The NPRM proposed to supersede AD 62-24-01 with a new AD
that would retain the actions required in AD 62-24-01 and only change
the inspection procedure from the dye penetrant method to the surface
eddy current method.

Comments

We provided the public the opportunity to participate in developing
this AD. The following presents the comments received on the proposal
and FAA's response to each comment:

Comment Issue No. 1: Change the Compliance Time for the Initial
Inspection

Larry Bierma, Joe Enzminger, John Aldous, Michael Vadeboncoeur,
John Rippinger, William E. Mayher, Dan Thomas, and Victor Barrett state
that the inspection compliance in the proposed AD is a duplication of
the inspection for those who have done the eddy current inspection
recently as part of compliance with an alternative method of compliance
(AMOC) to AD 2004-25-51.
The commenters state that requiring another eddy current inspection
within 6 months after the effective date of this AD would be
unnecessary and economically burdensome for those who have already done
it. The commenters request credit for the last inspection done in
compliance with an AMOC to AD 2004-25-51 as compliance for the initial
inspection required in the proposed AD.
We have rewritten the compliance time to give full credit for
previously accomplished eddy current inspections done in the area
affected by this AD.

Comment Issue No. 2: AD Is Not Necessary

Michael Vadeboncoeur, John Aldous, Mike Talbot, Eric Evans, Earle
Parks, Floyd Stilwell, Dan Thomas, Stephen Baksa, William Beitler, and
Terrance Brennan state that, since the time AD 62-24-01 was issued,
there have not been any accidents as a result of cracks in the
horizontal stabilizer. The commenters request the proposed AD be
withdrawn.
The commenters also request that stabilizer spars modified by Parks
Industries supplemental type certificate (STC) either be exempt from
the inspections or the inspection interval be increased to 1,000 hours
TIS.
We do not agree with the commenters. In 2005, 148 of the affected
airplanes were eddy current inspected. Cracks in the stabilizer spars
and/or spar webs were found on 6 of these airplanes, which required the
spars to be replaced. If no eddy current inspections had been done,
those cracks may have grown and reached critical crack lengths, which
could have compromised the integrity of the spar structure.
In order to increase the inspection interval or eliminate the spar
inspections, we need supporting engineering analysis data regarding
fatigue life, crack growth rate, etc. We have not received such data
for the spars modified by the Parks Industries STC.
If we receive engineering analysis data that supports increasing
the inspection intervals or eliminating the inspections, we may take
additional rulemaking action at that time.
We are not changing the final rule AD action based on these
comments.

Comment Issue No. 3: Retain the Dye Penetrant Inspection From AD 62-24-
01

Floyd Stilwell, Earle Parks, and Terrance Brennan state that the
surface eddy current inspection is expensive and inconvenient.
Qualified technicians to do the surface eddy current inspections have
to be brought to the repair station from other parts of the country,
which contributes to the expense of doing the eddy current inspection.
The commenters request retaining the dye penetrant inspection.
We do not agree with the commenters. AD 2001-13-18 R1 currently
requires owners/operators of all Beech Models 45 (YT-34), A45 (T-34A,
B-45), and D45 (T-34B) airplanes to do repetitive 80-hour TIS eddy
current inspections of the wing spar assemblies and other components
following Raytheon Aircraft Mandatory Service Bulletin No. SB 57-3329,
Part II, Page 3/65, Issued: February, 2000. If the wing spar and
stabilizer spar inspections are properly planned, these two inspections
could be done at the same time. This planning would eliminate any extra
expenses.
We have reason to believe that damage tolerance analysis of the
stabilizer spar is being conducted by some owners. This may result in
additional rulemaking action that could eliminate the inspection or
increase the inspection interval. Until that time, AMOCs for this AD
may be approved, if requested using the procedures found in 14 CFR
39.19.
We are not changing the final rule AD action based on these
comments.

Comment Issue No. 4: Surface Eddy Current Inspection Method Unwarranted

Dan Thomas, William Beitler, Floyd Stilwell, William Mayher, and
Mike Talbot state that the eddy current inspection method is no better
than the dye penetrant method for detecting cracks. The level of safety
will not be enhanced by changing the inspection methods. Further, the
eddy current method could produce false positives and the frequent
inspections could also incur damage to the stabilizer spar. The
commenters request the method of inspection be at the owner's/
operator's option.
We do not agree with the commenters. The eddy current inspection
method is a more sensitive inspection process. The dye penetrant
inspection method at times could completely miss detecting the cracks.
All inspection methods have some inherent drawbacks. Eddy current
inspection methods detect small surface cracks better than dye
penetrant methods, and eddy current inspection methods are also capable
of detecting subsurface cracks. Detection of cracks early is a definite
advantage. Eddy current inspection methods could occasionally produce
false positives; however, this could be avoided if cracks are confirmed
by repeatable flaw indications.
If the inspections required by this AD are carefully done by
qualified technicians, any damage to the spars could be prevented.
The 500-hour TIS repetitive inspection interval is a long interval
between inspections for this type of airplane, which normally will take
place once in 5 years or longer in most cases; therefore, we do not
consider this inspection requirement as frequent.
We are not changing the final rule AD action based on this comment.

Conclusion

We have carefully reviewed the available data and determined that
air safety and the public interest require adopting the AD as proposed
except for minor editorial corrections. We have determined that these
minor corrections:
Are consistent with the intent that was proposed in the
NPRM for correcting the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.

[[Page 10911]]

Costs of Compliance

We estimate that this AD affects 475 airplanes in the U.S.
registry.
We estimate the following costs to accomplish each inspection:

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Total cost per Total cost on
Labor cost Parts cost airplane U.S. operators
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8 work-hours x $80 per hour = $640............ Not applicable.................. $640 $304,000
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We estimate the following costs to do any necessary horizontal
stabilizer replacements that will be required based on the results of
the inspection. We have no way of determining the number of airplanes
that may need this replacement:

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Total cost per
Labor cost Parts cost airplane
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4 work-hours x $80 per hour = $320................................ $3,500 $3,820
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Cost Difference Between This AD and AD 62-24-01

The only difference between this AD and AD 62-24-01 is the change
of inspection method. There may be some minimal additional cost
involved in doing the eddy current inspection because of possible
equipment rentals necessary. No additional actions are being required.
We have determined that this AD action does not increase the cost
impact over that already required by AD 62-24-01.

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.
We are 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 AD.

Regulatory Findings

We have 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. Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979); 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.
We prepared a summary of the costs to comply with this AD (and
other information as included in the Regulatory Evaluation) and placed
it in the AD Docket. You may get a copy of this summary by sending a
request to us at the address listed under ADDRESSES. Include ``Docket
No. FAA-2006-25105; Directorate Identifier 2006-CE-33-AD'' in your
request.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator,
the Federal Aviation Administration amends part 39 of the Federal
Aviation Regulations (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 removing Airworthiness Directive (AD)
62-24-01, Amendment 39-508, and adding the following new AD:

2007-06-01 Raytheon Aircraft Company: Amendment 39-14982; Docket
No. FAA-2006-25105; Directorate Identifier 2006-CE-33-AD.

Effective Date

(a) This AD becomes effective on April 16, 2007.

Affected ADs

(b) This AD supersedes AD 62-24-01, Amendment 39-508.

Applicability

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Serial
Model numbers
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Beech 45 (YT-34)........................................ All
Beech A45 (T34A, B-45).................................. All
Beech D45 (T-34B)....................................... All
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Unsafe Condition

(d) This AD results from our determination that the surface eddy
current inspection method should be used in place of the dye penetrant
inspection method currently required in AD 62-24-01. We are issuing
this AD to prevent failure of the front and/or rear horizontal
stabilizer spars caused by fatigue cracks. This failure could result in
stabilizer separation and loss of control of the airplane.

Compliance

(e) Using the surface eddy current inspection procedures outlined
in the appendix of this AD, inspect the front and rear horizontal
stabilizer spars between the butt rib and the inboard end for cracks,
unless already done, as follows:
(1) If the last inspection of the front and rear horizontal
stabilizer spars was done using the surface eddy current method (or
FAA-approved equivalent method) to show compliance with

[[Page 10912]]

AD 62-24-01 and/or to show compliance with the alternative method of
compliance (AMOC) to AD 2004-25-51: Repetitively inspect thereafter at
intervals not to exceed 500 hours time-in-service (TIS).
(2) If the last inspection of the front and rear horizontal
stabilizer spars required by AD 62-24-01 was done using the dye
penetrant method: Inspect initially as presented in the table below and
repetitively thereafter at intervals not to exceed 500 hours TIS:

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If Then
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(i) Less than 200 hours TIS have passed Inspect at whichever of the
since the last inspection required by AD following occurs later:
62-24-01:
(A) Upon accumulating 200
hours TIS since the last
inspection required by AD
62-24-01; or
(B) Within the next 6 months
after April 16, 2007. (the
effective date of this AD).
(ii) If 200 hours TIS or more have passed Inspect at whichever of the
since the last inspection required by AD- following occurs first,
24-01: unless paragraph
(e)(2)(iii) of this AD
applies, as specified
below:
(A) At the next repetitive
inspection required by AD
62-24-01; or
(B) Within the next 6 months
after April 16, 2007 (the
effective date of this AD).
(iii) If paragraph (e)(2)(ii) results in Inspect within the next 30
the initial surface eddy current days after April 16, 2007.
inspection becoming mandatory within 30 (the effective date of this
days after the effective date of this AD: AD).
------------------------------------------------------------------------

Alternative Methods of Compliance (AMOCs)

(f) The Manager, Wichita Aircraft Certification Office, FAA, ATTN:
T.N. Baktha, Aerospace Engineer, 1801 Airport Road, Mid-Continent
Airport, Wichita, Kansas 67209; telephone: (316) 946-4155; fax: (316)
946-4107, has the authority to approve AMOCs for this AD, if requested
using the procedures found in 14 CFR 39.19.
(g) AMOCs approved for AD 62-24-01 are approved for this AD.

Appendix to AD 2007-06-01

Surface Eddy Current Inspection Procedure

Note: This surface eddy current inspection procedure is based on
T-34 Spar Corporation TSC 3506, Rev C, dated May 10, 2005. The T-34
Spar Corporation is allowing the use of this procedure to be
included in this Airworthiness Directive. Alternative methods of
compliance procedures will be allowed, if approved by the Wichita
Aircraft Certification Office and requested using the procedures
found in 14 CFR 39.19.

Purpose: This procedure is to be used to detect cracks in the
inner and outer spars of the front and rear spar assemblies of
Raytheon Aircraft Company Beech Models 45 (YT-34), A45 (T-34A, B-
45), and D45 (T-34B) airplane stabilizers outside of the steel
bushings in the attach holes.
Area To Be Inspected: To access the area of inspection, remove
the stabilizer from the airplane. The areas to be inspected include
the forward and aft surfaces of the inner and outer front and rear
spars of the horizontal stabilizers in the areas surrounding each of
the attach holes.
Preparing the Area for Inspection: Thoroughly clean area to be
inspected with solvent (acetone or equivalent) as required until no
signs of dirt, grime, or oil remain on the front and rear spars from
the closeout former inboard on the forward and aft surfaces of the
spars.
Surfaces to be inspected should be smooth and corrosion-free.
Any loss of thickness due to corrosion below material thickness
tolerance is cause for rejection of the structure. An ultrasonic
tester may be used to determine if material thickness has been
compromised.
Equipment Requirements: Nortec Stavely 2000D Eddy Current Tester
or equivalent.
Probe: 50-500 KHz, shielded, absolute, 0.071'' diameter (0.090
max. diameter), right angle, pencil style, surface probe, 5 long,
\1/2\'' drop or equivalent. Use 0.025'' notch (beyond head) for
calibration
Personal Requirements: Technicians with Eddy Current, Level II
or Level III per one of the following specifications: ATA
specification 105, SNT-TC-1A, or NAS-410 (MIL-std 410E).
Methods: Typical Set-up Parameters:
Frequency-350 KHz, Gain Vertical-75 dB, Horizontal-69 dB, Drive-
Mid, Filters- Lo Pass-30, Hi Pass-0, Lift off-Horizontal to the
left, adjust as required. The most reliable indication (minimum of
1\1/2\ to 2 graticules) of the smallest observable flaw in the
coupon (see the attached Figures) occurs from the notch extending
0.025'' past the edge of the nominal fastener head (total notch
length of 0.100'' from the edge of the nominal hole). Install
appropriate aluminum guide pin into bushing such that the edge of
the guide pin is flush with the edge of the bushing. Using the pin
(see the attached Figures) as a guide, circle the area surrounding
the steel bushing with the probe and adjacent area (approximately
\1/4\'') to inspect for cracks. Inspect forward and aft surfaces
surrounding bushings of each spar.

Note: T-34 Spar Corporation, 2800 Airport Road, Hanger A, Ada,
Oklahoma, 74820 is a source for these coupons and pin.

Accept/Reject Criteria: Any repeatable flaw indication is cause
for rejection in accordance with the procedure. In the event that
any crack is detected, describe the flaw in detail providing sketch
as needed and send the information to the Wichita ACO.
Documentation Requirements: Record inspection findings in the
aircraft logbook.
BILLING CODE 4910-13-P

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Issued in Kansas City, Missouri, on March 5, 2007.
Kim Smith,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 07-1106 Filed 3-9-07; 8:45 am]

BILLING CODE 4910-13-C