[Federal Register Volume 72, Number 66 (Friday, April 6, 2007)]
[Rules and Regulations]
[Pages 16990-16998]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 07-1715]


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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 39-15016; AD 2007-06-01 R1]
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; correction.

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SUMMARY: We are clarifying information contained in Airworthiness 
Directive (AD) 2007-06-01, which supersedes AD 62-24-01 and applies to 
all Raytheon Aircraft Company (RAC) Beech Models 45 (YT-34), A45 (T-
34A, B45), and D45 (T-34B) airplanes. AD 2007-06-01 currently requires 
you to repetitively inspect, using the eddy current method, the front 
and rear horizontal stabilizer spars for cracks and replace any cracked 
stabilizer. We inadvertently left out the language in this AD that 
required replacement of any horizontal stabilizer spar found cracked 
prior to further flight although the procedures in the appendix made 
reference to corrective action. The replacement information was 
contained in the notice of proposed rulemaking (NPRM). This document 
adds this information already proposed back into the AD. 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 16991]]

Discussion

    On March 5, 2007, we issued AD 2007-06-01, Amendment 39-14982 (72 
FR 10909, March 12, 2007), to supersede AD 62-24-01. AD 2007-06-01 
retained inspections of the front and rear horizontal stabilizer spars 
for cracks, but changed the inspection method from the dye penetrant 
method to the surface eddy current method.
    We inadvertently left out the language in AD 2007-06-01 that 
required replacement of any horizontal stabilizer spar found cracked 
prior to further flight although the procedures in the appendix made 
reference to corrective action. The replacement information was 
contained in the NPRM.
    Consequently, the FAA sees a need to clarify AD 2007-06-01 to 
assure that any cracked horizontal stabilizer spar is replaced prior to 
further flight.

Correction of Publication

    This document clarifies AD 2007-06-01 by incorporating the 
replacement language that was proposed in the NPRM and adds the 
amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 
39.13).
    Since this action only clarifies the intent of what was originally 
proposed in the NPRM, it has no adverse economic impact and imposes no 
additional burden on any person than was already proposed. Therefore, 
the FAA has determined that prior notice and opportunity for public 
comment are unnecessary.

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) 
2007-06-01, Amendment 39-14982 (72 FR 10909, March 12, 2007), and 
adding the following new AD:

2007-06-01 R1 Raytheon Aircraft Company: Amendment 39-15016; 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 revises AD 2007-06-01, Amendment 39-14982, which 
superseded 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  Nos.
------------------------------------------------------------------------
Beech 45 (YT-34)............................  All.
Beech A45 (T34A, B-45)......................  All.
Beech D45 (T-34B)...........................  All.
------------------------------------------------------------------------

Unsafe Condition

    (d) This AD is intended to prevent failure of the front and/or 
rear horizontal stabilizer spars caused by fatigue cracks by 
changing the inspection method from dye penetrant to surface eddy 
current. 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 presented below. If any crack is 
found in either spar or the reinforcing doubler during any 
inspection required by this AD, prior to further flight, replace the 
stabilizer and continue to repetitively inspect at intervals not to 
exceed 500 hours time-in-service (TIS).
    (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 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 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 since the     Inspect at whichever of the following occurs later:
 last inspection required by AD 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) 200 hours TIS or more have passed since the      Inspect at whichever of the following occurs first, unless
 last inspection required by AD 62-24-01:              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) Paragraph (e)(2)(ii) results in the initial     Inspect within the next 30 days after April 16, 2007 (the
 surface eddy current inspection becoming mandatory    effective date of this AD).
 within 30 days after the effective date of this AD:
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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 R1--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.

[[Page 16992]]

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, 
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 
\1/2\ 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.

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    Issued in Kansas City, Missouri, on March 30, 2007.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 07-1715 Filed 4-5-07; 8:45 am]
BILLING CODE 4910-13-P