[Federal Register Volume 72, Number 47 (Monday, March 12, 2007)]
[Rules and Regulations]
[Pages 10909-10918]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 07-1106]


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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:

----------------------------------------------------------------------------------------------------------------
                                                                                  Total cost per   Total cost on
                  Labor cost                               Parts cost                airplane     U.S. operators
----------------------------------------------------------------------------------------------------------------
8 work-hours x $80 per hour = $640............  Not applicable..................            $640        $304,000
----------------------------------------------------------------------------------------------------------------

    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:

----------------------------------------------------------------------------------------------------------------
                                                                                                  Total cost per
                            Labor cost                                       Parts cost              airplane
----------------------------------------------------------------------------------------------------------------
4 work-hours x $80 per hour = $320................................                        $3,500          $3,820
----------------------------------------------------------------------------------------------------------------

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

    (c) This AD affects the following airplane models and serial 
numbers that are certificated in any category:

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

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:

------------------------------------------------------------------------
                    If                                  Then
------------------------------------------------------------------------
(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