[Federal Register Volume 71, Number 146 (Monday, July 31, 2006)]
[Proposed Rules]
[Pages 43075-43083]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-6581]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 71, No. 146 / Monday, July 31, 2006 / 
Proposed Rules  

[[Page 43075]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25105; Directorate Identifier 2006-CE-33-AD]
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), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to supersede Airworthiness Directive (AD) 62-24-01, 
which applies to all Raytheon Aircraft Company (Raytheon) 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 dye penetrant inspection method may not detect 
cracks before failure of the horizontal stabilizer spars. Therefore, we 
are proposing to require the surface eddy current inspection method to 
detect cracks in the horizontal stabilizer spars. Consequently, this 
proposed AD would retain the actions required in AD 62-24-01 and change 
the required inspection method from dye penetrant to surface eddy 
current. We are proposing this AD to prevent failure of the front and 
rear horizontal stabilizer spars caused by fatigue cracks. This failure 
could result in stabilizer separation and loss of control of the 
airplane.

DATES: We must receive comments on this proposed AD by September 29, 
2006.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD:
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Governmentwide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-0001.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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; facsimile: 
(316) 946-4107.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include the docket number, ``FAA-
2006-25105; Directorate Identifier 2006-CE-33-AD'' at the beginning of 
your comments. We specifically invite comments on the overall 
regulatory, economic, environmental, and energy aspects of the proposed 
AD. We will consider all comments received by the closing date and may 
amend the proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact we 
receive concerning this proposed AD.

Discussion

    Fatigue cracks found in the horizontal stabilizer spars caused us 
to issue AD 62-24-01, Amendment 39-508. AD 62-24-01 currently requires 
the following on all Raytheon Beech Models 45 (YT-34), A45 (T-34A, 
B45), and D45 (T-34B) airplanes:
     Repetitive inspections, using the dye penetrant method at 
500-hour time-in-service (TIS) intervals, of the front and rear 
horizontal stabilizer spars between the butt rib and the inboard end 
for cracks; and
     Replacement of the horizontal stabilizer if cracks are 
found in either spar or the reinforcing doubler.
    Investigation of a T-34 series airplane accident where the wing 
separated in flight revealed fatigue cracks in the stabilizer spar root 
sections. These spar root sections were inspected for fatigue cracks 
using the dye penetrant method (as required by AD 62-24-01) just 281 
hours TIS before the fatal accident.
    Since 281 hours TIS is much shorter than the 500-hour TIS 
inspection interval required by this AD, we have determined that using 
dye penetrant inspection method may not detect cracks before failure of 
the horizontal stabilizer spars. Therefore, we are proposing to require 
the surface eddy current inspection method to detect cracks in the 
horizontal stabilizer spars.
    This condition, if not corrected, could result in failure of the 
horizontal stabilizer spars caused by fatigue cracks, which could 
result in stabilizer separation and loss of control of the airplane.

FAA's Determination and Requirements of This Proposed AD

    We are proposing this AD because we evaluated all information and 
determined the unsafe condition described previously is likely to exist 
or develop on other products of the same type design. This proposed AD 
would 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.

Costs of Compliance

    We estimate that this proposed AD would affect 475 airplanes in the 
U.S. registry.
    We estimate the following costs to do the proposed inspection:

[[Page 43076]]



----------------------------------------------------------------------------------------------------------------
                                                          Total cost per
            Labor cost                  Parts cost           airplane          Total cost on U.S.  operators
----------------------------------------------------------------------------------------------------------------
8 work-hours x $80 per hour =      Not applicable......             $640   $640 x 475 = $304,000.
 $640.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the proposed inspection. 
We have no way of determining the number of airplanes that may need 
this replacement:

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

Cost Difference Between This Proposed AD and AD 62-24-01

    The only difference between this proposed AD and AD 62-24-01 is the 
proposed change of inspection method. There may be some minimal 
additional cost involved in doing the proposed eddy current inspection 
because of possible equipment rentals necessary. No additional actions 
are being proposed. We have determined that this proposed 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 
rulemaking action.

Regulatory Findings

    We have 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 that the proposed 
regulation:
    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 regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket.

Examining the AD Docket

    You may examine the AD docket that contains the proposed AD, the 
regulatory evaluation, any comments received, and other information on 
the Internet at http://dms.dot.gov; or in person at the Docket 
Management Facility between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The Docket Office (telephone (800) 647-5227) 
is located at the street address stated in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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 removing Airworthiness Directive 
(AD) 62-24-01, Amendment 39-508, and adding the following new AD:

Raytheon Aircraft Company: Docket No. FAA-2006-25105; Directorate 
Identifier 2006-CE-33-AD.

Comments Due Date

    (a) We must receive comments on this airworthiness directive 
(AD) action by September 29, 2006.

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:

------------------------------------------------------------------------
                   Model                           Serial  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 rear 
horizontal stabilizer spars caused by fatigue cracks. This failure 
could result in stabilizer separation and loss of control of the 
airplane.

Compliance

    (e) To address this problem, you must do the following:

[[Page 43077]]



------------------------------------------------------------------------
           Actions                 Compliance            Procedures
------------------------------------------------------------------------
(1) Using the surface eddy    At the next           The surface eddy
 current inspection            repetitive            current inspection
 procedures outlined in the    inspection interval   procedures are
 appendix of this AD,          required by AD 62-    contained in the
 inspect the front and rear    24-01 or within the   appendix to this
 horizontal stabilizer spars   next 6 months after   AD.
 between the butt rib and      the effective date
 the inboard end for cracks.   of this AD,
                               whichever occurs
                               first. Repetitively
                               inspect thereafter
                               at intervals not to
                               exceed 500 hours
                               time-in-service
------------------------------------------------------------------------
(2) If any crack is found in  Before further        Not applicable.
 either spar or the            flight after the
 reinforcing doubler during    inspection in which
 any inspection required in    the crack is found.
 paragraph (e)(1) of this      After the
 AD, replace the stabilizer.   replacement,
                               continue with the
                               repetitive
                               inspection
                               requirement in
                               paragraph (e)(1) of
                               this AD
------------------------------------------------------------------------

Alternative Methods of Compliance (AMOCs)

    (f) The Manager, Wichita Aircraft Certification Office (ACO), 
FAA, ATTN: T.N. Baktha, Aerospace Engineer, Wichita ACO, 1801 
Airport Road, Mid-Continent Airport, Wichita, Kansas 67209; 
telephone: (316) 946-4155; facsimile: (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.

Related Information

    (h) 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, or on the Internet at http://dms.dot.gov. The docket number is Docket No. FAA-2006-25105; 
Directorate Identifier 2006-CE-33-AD.

Appendix to Docket No. FAA-2006-25105

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 attach 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

[[Page 43078]]

[GRAPHIC] [TIFF OMITTED] TP31JY06.001


[[Page 43079]]


[GRAPHIC] [TIFF OMITTED] TP31JY06.002


[[Page 43080]]


[GRAPHIC] [TIFF OMITTED] TP31JY06.003


[[Page 43081]]


[GRAPHIC] [TIFF OMITTED] TP31JY06.004


[[Page 43082]]


[GRAPHIC] [TIFF OMITTED] TP31JY06.005



[[Page 43083]]


    Issued in Kansas City, Missouri, on July 24, 2006.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.

[FR Doc. 06-6581 Filed 7-28-06; 8:45 am]
BILLING CODE 4910-13-C