Federal Register / Vol. 74, No. 60 / Tuesday, March 31, 2009 / Rules and Regulations 14465 

627–5210; has the authority to approve 

AMOCs for this AD, if requested using the 

procedures found in 14 CFR 39.19. 

(2) To request a different method of 

compliance or a different compliance time 

for this AD, follow the procedures in 14 CFR 

39.19. Before using any approved AMOC on 

any airplane to which the AMOC applies, 

notify your appropriate principal inspector 

(PI) in the FAA Flight Standards District 

Office (FSDO), or lacking a PI, your local 

FSDO. 

Material Incorporated by Reference 

(h) You must use Boeing Alert Service 

Bulletin 717–29A0009, dated July 31, 2008, 

to do the actions required by this AD, unless 

the AD specifies otherwise. 

(1) The Director of the Federal Register 

approved the incorporation by reference of 

this service information under 5 U.S.C. 

552(a) and 1 CFR part 51. 

(2) For service information identified in 

this AD, contact Boeing Commercial 

Airplanes, Attention: Data & Services 

Management, 3855 Lakewood Boulevard, MC 

D800–0019, Long Beach, California 90846– 

0001; telephone 206–544–5000, extension 2; 

fax 206–766–5683; e-mail 

dse.boecom@boeing.com; Internet https:// 

www.myboeingfleet.com. 

(3) You may review copies of the service 

information at the FAA, Transport Airplane 

Directorate, 1601 Lind Avenue SW., Renton, 

Washington. For information on the 

availability of this material at the FAA, call 

425–227–1221 or 425–227–1152. The service 

information is also available at http:// 

www.regulations.gov. 

(4) You may also review copies of the 

service information that is incorporated by 

reference at the National Archives and 

Records Administration (NARA). For 

information on the availability of this 

material at NARA, call 202–741–6030, or go 

to: http://www.archives.gov/federal_register/ 

code_of_federal_regulations/ 

ibr_locations.html. 

Issued in Renton, Washington, on March 

17, 2009. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E9–7001 Filed 3–30–09; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2006–23646; Directorate 

Identifier 2006–CE–005–AD; Amendment 

39–15849; AD 2006–08–08 R1] 

RIN 2120–AA64 

Airworthiness Directives; Air Tractor, 

Inc. Models AT–400, AT–401, AT–401B, 

AT–402, AT–402A, and AT–402B 

Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final rule. 

SUMMARY: We are adopting a new 

airworthiness directive (AD) to revise 

AD 2006–08–08, which applies to 

certain Air Tractor, Inc. (Air Tractor) 

Models AT–400, AT–401, AT–401B, 

AT–402, AT–402A, and AT–402B 

airplanes. AD 2006–08–08 currently 

requires you to repetitively eddy current 

inspect the wing lower spar cap in order 

to reach the safe life and, for certain 

Models AT–402A and AT–402B 

airplanes and those that incorporate or 

have incorporated Marburger 

Enterprises, Inc. (Marburger) winglets, 

lowers the safe life for the wing lower 

spar cap. Since we issued AD 2006–08– 

08, we have received information to 

update inspection intervals for the 

Models AT–401B, AT–402A, and AT– 

402B airplanes based on a revised 

damage tolerance analysis. 

Consequently, this AD would not only 

retain the actions of AD 2006–08–08, 

but would reduce the number of 

repetitive inspections for all affected 

Model AT–401B airplanes and certain 

Models AT–402A and AT–402B 

airplanes. We are issuing this AD to 

prevent fatigue cracks from occurring in 

the wing lower spar cap before the 

originally established safe life is 

reached. Fatigue cracks in the wing 

lower spar cap, if not detected and 

corrected, could result in wing 

separation and loss of control of the 

airplane. 

DATES: This AD becomes effective on 

May 5, 2009. 

As of April 21, 2006 (71 FR 19986, 

April 19, 2006), the Director of the 

Federal Register approved the 

incorporation by reference of Snow 

Engineering Co. Drawing 21088, dated 

November 3, 2004; Snow Engineering 

Co. Process Specification 197, page 1, 

revised June 4, 2002, pages 2 through 4, 

dated February 23, 2001, and page 5, 

dated May 3, 2002; and Snow 

Engineering Co. Service Letter 202, page 

3, dated October 16, 2000, listed in this 

AD. 

ADDRESSES: For service information 

identified in this AD, contact Air 

Tractor, Incorporated, P.O. Box 485, 

Olney, Texas 76374; telephone: (940) 

564–5616; facsimile: (940) 564–5612; 

Internet: http://www.airtractor.com; or 

Marburger Enterprises, Inc., 1227 

Hillcourt, Williston, North Dakota 

58801; telephone: (800) 893–1420 or 

(701) 774–0230; facsimile: (701) 572– 

2602. 

To view the AD docket, go to U.S. 

Department of Transportation, Docket 

Operations, M–30, West Building 

Ground Floor, Room W12–140, 1200 

New Jersey Avenue, SE., Washington, 

DC 20590, or on the Internet at http:// 

www.regulations.gov. The docket 

number is FAA–2006–23646; 

Directorate Identifier 2006–CE–005–AD. 

FOR FURTHER INFORMATION CONTACT: 

Direct all questions to: 

—For airplanes that do not incorporate 

and never have incorporated 

Marburger winglets: Rob Romero, 

Aerospace Engineer, FAA, Fort Worth 

Airplane Certification Office, 2601 

Meacham Boulevard, Fort Worth, 

Texas 76193–0150; telephone: (817) 

222–5102; facsimile: (817) 222–5960; 

and 

—For airplanes that incorporate or have 

incorporated Marburger Enterprises, 

Inc. winglets: John Cecil, Aerospace 

Engineer, Los Angeles Aircraft 

Certification Office, FAA, 3960 

Paramount Boulevard, Lakewood, 

California 90712; telephone: (562) 

627–5228; facsimile: (562) 627–5210. 

SUPPLEMENTARY INFORMATION: 

Discussion 

On December 4, 2008, 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 

certain Air Tractor Models AT–400, 

AT–401, AT–401B, AT–402, AT–402A, 

and AT–402B airplanes. This proposal 

was published in the Federal Register 

as a notice of proposed rulemaking 

(NPRM) on December 10, 2008 (73 FR 

74999). The NPRM proposed to revise 

AD 2006–08–08 with a new AD that 

would not only retain the actions of AD 

2006–08–08, but would reduce the 

number of repetitive inspections for all 

affected Model AT–401B airplanes and 

certain Models AT–402A and AT–402B 

airplanes. 

The following table contains AD 

actions that address the wing spar safe 

life of the Air Tractor airplane fleet: 


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RELATED AD ACTIONS

AD No. Affected air tractor airplane model Issue date 

2003–07–04 .......................................... AT–300, AT–400, AT–400A, AT–401, AT–401B, AT–402, AT–402A, AT–402B, 

AT–501, AT–502, and AT–502B.

March 25, 2003. 

2006–08–08 .......................................... AT–400; AT–401, AT–401B, AT–402, AT–402A, and AT–402B ........................ April 10, 2006. 

2006–08–09 .......................................... AT–802 and AT–802A ......................................................................................... April 10, 2006. 

2006–23–09 .......................................... AT–602 ................................................................................................................. October 26, 2006. 

2006–24–10 .......................................... AT–501, AT–502, AT–502A, AT–502B, and AT–503A ....................................... November 22, 2006. 

2008–09–10 .......................................... AT–300, AT–301, AT–302, AT–400, and AT–400A ............................................ April 18, 2008. 

You may view these Airworthiness 

Directives at the following Internet Web 

site addresses: http://rgl.faa.gov or 

http://www.gpoaccess.gov/fr/ 

index.html. 

Comments 

We provided the public the 

opportunity to participate in developing 

this AD. The following presents the 

comment received on the proposal and 

FAA’s response to the comment: 

Comment Issue: Reduce Applicability 

Mr. David Ligon, Air Tractor, 

comments that since issuance of AD 

2006–08–08, the 21058–1/-2 lower spar 

cap is standard on production Models 

401B, 402A, and 402B airplanes 

beginning with SN 1183. Consequently, 

he recommends that the applicability of 

the proposed AD end at SN 1182; 

production airplanes following this SN 

have installed the 21058–1/-2 lower 

spar cap. 

We agree with the commenter and are 

changing the AD to reflect the 

installation of the 21058–1/-2 lower spar 

cap on production Models 401B, 402A, 

and 402B airplanes beginning with SN 

1183. 

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 

the changes previously discussed and 

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. 

Costs of Compliance 

We estimate that this AD affects 341 

airplanes in the U.S. registry. 

We estimate the following costs to do 

the inspection. We have no way of 

determining the number of airplanes 

that may need repair or modification as 

a result of any inspection: 

Labor cost Parts cost Total cost per airplane Total cost on U.S. 

operators 

* $500 to $800 ............................... Not Applicable .............................. $500 to $800 ................................ $170,500 to $272,800. 

* Eddy current inspections are an estimated flat cost that includes labor and use of equipment. 

We estimate the following costs to do 

the modification. We have no way of 

determining the number of airplanes 

that may need this modification: 

Labor cost Parts cost Total cost per 

airplane 

120 work-hours × $80 = $9,600 .............................................................................................................................. $11,500 $21,100 

We estimate the following costs to do 

the replacement. We have no way of 

determining the number of airplanes 

that may need this replacement: 

Labor cost Parts cost Total cost per 

airplane 

$16,500 .................................................................................................................................................................... $16,500 $33,000 

* The labor costs of the replacement are an estimated flat cost that includes labor and use of equipment. 

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 


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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–2006–23646; 

Directorate Identifier 2006–CE–005– 

AD’’ in your request. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Incorporation by reference, 

Safety. 

Adoption of the Amendment 

■ 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 

■ 1. The authority citation for part 39 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701. 

§ 39.13 [Amended] 

■ 2. The FAA amends § 39.13 by 

removing Airworthiness Directive (AD) 

2006–08–08, Amendment 39–14563 (71 

FR 19986, April 19, 2006), and adding 

the following new AD: 

2006–08–08 R1 Air Tractor, Inc.: 

Amendment 39–15849; Docket No. 

FAA–2006–23646; Directorate Identifier 

2006–CE–005–AD. 

Effective Date 

(a) This AD becomes effective on May 5, 

2009. 

Affected ADs 

(b) This AD revises AD 2006–08–08, 

Amendment 39–14563. 

Applicability 

(c) This AD applies to certain Models AT– 

400, AT–401, AT–401B, AT–402, AT–402A, 

and AT–402B airplanes that are certificated 

in any category. Use paragraph (c)(1) of this 

AD for affected airplanes that do not 

incorporate and never have incorporated 

Marburger winglets. Use paragraph (c)(3) of 

this AD for airplanes that have been modified 

to install lower spar caps, part number (P/N) 

21058–1 and P/N 21058–2. Use paragraph 

(c)(4) of this AD for certain Models AT–401, 

AT–401B, AT–402, AT–402A, and AT–402B 

airplanes that incorporate or have 

incorporated Marburger winglets. 

(1) The following table applies to airplanes 

that do not incorporate and never have 

incorporated Marburger winglets along with 

the safe life (presented in hours time-inservice (TIS)) of the wing lower spar cap for 

all affected airplane models and serial 

numbers (SNs): 

TABLE 1—SAFE LIFE FOR AIRPLANES THAT DO NOT INCORPORATE AND NEVER HAVE INCORPORATED MARBURGER

WINGLETS

Model SNs 

Wing lower 

spar cap safe 

life 

(hours TIS) 

AT–400 ..................................................... All beginning with 0416 ................................................................................................ 13,300 

AT–401 ..................................................... 0662 through 0951 ....................................................................................................... 10,757 

AT–401B ................................................... 0952 through 1020, except 1015 ................................................................................. 6,948 

AT–401B ................................................... 1015 and 1021 through 1182 ...................................................................................... 7,777 

AT–402 ..................................................... 0694 through 0951 ....................................................................................................... 7,440 

AT–402A ................................................... 0738 through 0951 ....................................................................................................... 7,440 

AT–402A ................................................... 0952 through 1020 ....................................................................................................... 2,000 

AT–402A ................................................... 1021 through 1182 ....................................................................................................... 2,300 

AT–402B ................................................... 0966 through 1020, except 1015 ................................................................................. 2,000 

AT–402B ................................................... 1015 and 1021 through 1182 ...................................................................................... 2,300 

(2) If piston-powered aircraft have been 

converted to turbine power, you must use the 

limits for the corresponding serial number 

(SN) turbine-powered aircraft. 

(3) If you have an aircraft that has been 

modified by installing lower spar caps, P/N 

21058–1 and P/N 21058–2, you must use a 

wing lower spar cap safe life of 9,800 hours 

TIS. No inspections are required to reach this 

life. 

(i) Airplane SNs beginning with 1183 and 

those that have been modified with 

replacement spar caps, P/N 21058–1 and 

P/N 21058–2, are not eligible to have 

Supplemental Type Certificate (STC) No. 

SA00490LA, Marburger winglets, installed. 

(ii) If your airplane currently has spar caps, 

P/N 21058–1 and P/N 21058–2, and winglets 

installed, then you must remove the winglets 

before further flight and you must contact the 

FAA at the address in paragraph (m)(1) of 

this AD for a new safe life. 

(4) The following table applies to airplanes 

that incorporate or have incorporated 

Marburger winglets. These winglets are 

installed following STC No. SA00490LA. Use 

the winglet usage factor in Table 2 of 

paragraph (c)(4) of this AD, the wing lower 

spar cap safe life specified in Table 1 of 

paragraph (c)(1) of this AD, and the 

instructions included in Appendix 1 to this 

AD to determine the new safe life of 

airplanes that incorporate or have 

incorporated Marburger winglets: 

TABLE 2—WINGLET USAGE FACTOR TO DETERMINE THE SAFE LIFE FOR AIRPLANES THAT INCORPORATE OR HAVE

INCORPORATED MARBURGER WINGLETS PER STC NO. SA00490LA 

Model SNs Winglet usage 

factor 

AT–401 ..................................................... 0662 through 0951 ....................................................................................................... 1.6 

AT–401B ................................................... 0952 through 1020, except 1015 ................................................................................. 1.1 

AT–401B ................................................... 1015 and 1021 through 1182 ...................................................................................... 1.1 

AT–402 ..................................................... 0694 through 0951 ....................................................................................................... 1.6 


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TABLE 2—WINGLET USAGE FACTOR TO DETERMINE THE SAFE LIFE FOR AIRPLANES THAT INCORPORATE OR HAVE

INCORPORATED MARBURGER WINGLETS PER STC NO. SA00490LA—Continued 

Model SNs Winglet usage 

factor 

AT–402A ................................................... 0738 through 0951 ....................................................................................................... 1.6 

AT–402A ................................................... 0952 through 1020 ....................................................................................................... 1.1 

AT–402A ................................................... 1021 through 1182 ....................................................................................................... 1.1 

AT–402B ................................................... 0966 through 1020, except 1015 ................................................................................. 1.1 

AT–402B ................................................... 1015 and 1021 through 1182 ...................................................................................... 1.1 

Unsafe Condition 

(d) This AD is the result of fatigue cracking 

of the wing main spar lower cap at the center 

splice joint outboard fastener hole. The 

actions specified in this AD are intended to 

detect and correct cracks in the wing main 

spar lower cap, which could result in failure 

of the spar cap and lead to wing separation 

and loss of control of the airplane. 

Compliance 

(e) Safe Life Record: For all affected 

airplanes, modify the applicable aircraft 

records (logbook) as follows to show the safe 

life for the wing lower spar cap listed in this 

AD (use the information from paragraph (c) 

of this AD and Appendix 1 to this AD, as 

applicable). 

(1) Incorporate the following into the 

aircraft logbook: ‘‘Following this AD, the 

wing lower spar cap is life limited to 

llll hours time-in-service (TIS).’’ Insert 

the applicable safe life number from the 

applicable tables in paragraph (c) of this AD 

and Appendix 1 to this AD. 

(i) Do the logbook entry within the next 10 

hours TIS after April 21, 2006 (the effective 

date of AD 2006–08–08). 

(ii) A person holding at least a private pilot 

certificate as authorized by section 43.7 of 

the Federal Aviation Regulations (14 CFR 

43.7) may modify the aircraft records. Make 

an entry into the aircraft logbook showing 

compliance with this portion of the AD in 

accordance with section 43.9 of the Federal 

Aviation Regulations (14 CFR 43.9). 

(2) Wing Spar Replacement: For all affected 

airplanes, replace the wing lower spar cap 

following Snow Engineering Drawing 

Number 21088, dated November 3, 2004. 

Replace upon accumulating the safe life used 

in paragraph (e)(1) of this AD or within the 

next 50 hours TIS after April 21, 2006 (the 

effective date of AD 2006–08–08), whichever 

occurs later. The owner/operator may not do 

the spar cap replacement, unless he/she is a 

properly certified mechanic. 

(f) Inspection Requirements: For all 

affected airplanes, except Model AT–402A, 

SNs 0952 through 1182, and except Model 

AT–402B, SNs 0966 through 1182, do the 

initial inspection of the outboard two lower 

spar cap bolt holes using the wing spar lower 

cap TIS schedules listed in Table 3. Follow 

Snow Engineering Co. Process Specification 

#197, page 1, revised June 4, 2002, pages 2 

through 4, dated February 23, 2001, and page 

5, dated May 3, 2002. After the initial 

inspection, perform repetitive inspections at 

the repetitive inspection intervals listed in 

Table 3. Use the same procedure for the 

repetitive inspections as for the initial 

inspection. If not already done, install access 

panels at the time of the first inspection 

following Snow Engineering Service Letter 

#202, page 3, dated October 16, 2000. 

Note: Hours listed in the table are in hours 

TIS and the phrase ‘‘within the lll next 

hours’’ refers to ‘‘within the next lll 

hours after April 21, 2006 (the effective date 

of AD 2006–08–08).’’ 

TABLE 3—INSPECTION TIMES

Model SNs Current wing spar lower 

cap TIS hours Initial inspection 

Repetitive 

inspection 

interval 

(hours) 

AT–400 ........ All beginning with 0416 ..... Greater than 7,750 ............ Within the next 50 hours TIS or upon the accumulation of 8,000 hours TIS, whichever is later.900 

AT–401 ........ 0662–0951 ......................... Greater than 6,250 ............ Within the next 50 hours TIS or upon the accumulation of 6,500 hours TIS, whichever is later.700 

AT–401 ........ 0662–0951 ......................... Greater than 4,350 but 

less than or equal to 

6,250.

Within the next 250 hours TIS or upon the accumulation of 4,850 hours TIS, whichever is later.700 

AT–401 ........ 0662–0951 ......................... Greater than 2,750 but 

less than or equal to 

4,350.

Within the next 500 hours TIS ...................................... 700 

AT–401 ........ 0662–0951 ......................... Less than or equal to 

2,750.

Upon the accumulation of 3,250 hours TIS .................. 700 

AT–401B ...... 0952–1020 except 1015 .... Greater than 3,950 ............ Within the next 50 hours TIS or upon the accumulation of 4,200 hours TIS, whichever is later.600 

AT–401B ...... 0952–1020 except 1015 .... Greater than 2,650 but 

less than or equal to 

3,950.

Within the next 250 hours TIS or upon the accumulation of 3,150 hours TIS, whichever is later.600 

AT–401B ...... 0952–1020 except 1015 .... Greater than 1,600 but 

less than or equal to 

2,650.

Within the next 500 hours TIS ...................................... 600 

AT–401B ...... 0952–1020 except 1015 .... Less than or equal to 

1,600.

Upon the accumulation of 2,100 hours TIS .................. 600 

AT–401B ...... 1015 and 1021–1124 ........ Greater than 4,450 ............ Within the next 50 hours TIS or upon the accumulation of 4,700 hours TIS, whichever is later.600 

AT–401B ...... 1015 and 1021–1124 ........ Greater than 3,000 but 

less than or equal to 

4,450.

Within the next 250 hours TIS or upon the accumulation of 3,500 hours TIS, whichever is later.600 

AT–401B ...... 1015 and 1021–1124 ........ Greater than 1,850 but 

less than or equal to 

3,000.

Within the next 500 hours TIS ...................................... 600 


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TABLE 3—INSPECTION TIMES—Continued 

Model SNs Current wing spar lower 

cap TIS hours Initial inspection 

Repetitive 

inspection 

interval 

(hours) 

AT–401B ...... 1015 and 1021–1124 ........ Less than or equal to 

1,850.

Upon the accumulation of 2,350 hours TIS .................. 600 

AT–401B ...... 1125 through 1182 ............ Greater than 4,450 ............ Within the next 50 hours TIS or upon the accumulation of 4,700 hours TIS, whichever is later.1,000 

AT–401B ...... 1125 through 1182 ............ Greater than 3,000 but 

less than or equal to 

4,450.

Within the next 250 hours TIS or upon the accumulation of 3,500 hours TIS, whichever is later.1,000 

AT–401B ...... 1125 through 1182 ............ Greater than 1,850 but 

less than or equal to 

3,000.

Within the next 500 hours TIS ...................................... 1,000 

AT–401B ...... 1125 through 1182 ............ Less than or equal to 

1,850.

Upon the accumulation of 2,350 hours TIS .................. 1,000 

AT–402/AT– 

402A.

0694–0951 ......................... Greater than 4,250 ............ Within the next 50 hours TIS or upon the accumulation of 4,500, whichever is later.700 

AT–402/AT– 

402A.

0694–0951 ......................... Greater than 2,850 but 

less than or equal to 

4,250.

Within the next 250 hours TIS or upon the accumulation of 3,350 hours TIS, whichever is later.700 

AT–402/AT– 

402A.

0694–0951 ......................... Greater than 1,750 but 

less than or equal to 

2,850.

Within the next 500 hours TIS ...................................... 700 

AT–402/AT– 

402A.

0694–0951 ......................... Less than or equal to 

1,750.

Upon the accumulation of 2,250 hours TIS .................. 700 

(g) For all affected airplanes: Before further 

flight after the inspection in which cracks are 

found, replace any cracked wing lower spar 

cap following Snow Engineering Drawing 

Number 21088, dated November 3, 2004. 

(h) For Models AT–400, AT–401, AT–401B, 

and AT–402 airplanes, SNs 0952 through 

1182: Report to the FAA any cracks detected 

as the result of each inspection required by 

paragraph (f) of this AD on the form in Figure 

1 of this AD. 

(1) Only if cracks are found, send the 

report within 10 days after the inspection 

required in paragraph (f) of this AD. 

(2) The Office of Management and Budget 

(OMB) approved the information collection 

requirements contained in this regulation 

under the provisions of the Paperwork 

Reduction Act and assigned OMB Control 

Number 2120–0056. 

(i) For all affected airplanes: Upon the 

accumulation of the life used in paragraph 

(e)(1) of this AD or within the next 50 hours 

TIS after April 21, 2006 (the effective date of 

AD 2006–08–08), whichever occurs later, you 

must replace your wing lower spar cap before 

further flight following Snow Engineering 

Drawing Number 21088, dated November 3, 

2004. 

(j) For Model AT–402A airplanes, SNs 0952 

through 1182; and Model AT–402B airplanes, 

SNs 0966 through 1182: In lieu of the safe life 

used in paragraph (e)(1) of this AD, you may 

eddy-current inspect and modify the wing 

lower spar cap as specified in the alternative 

method of compliance in AD 2006–08–08, 

which is approved for this AD (see paragraph 

(o) of this AD for more information). 

(k) For all affected airplanes (those 

complying with the actions in the AD or 

alternative method of compliance (AMOC)): 

One of the following must do the inspection: 

(1) A level 2 or 3 inspector certified in 

eddy current inspection using the guidelines 

established by the American Society for 

Nondestructive Testing or MIL–STD–410; or 

(2) A person authorized to perform AD 

work and who has completed and passed the 

Air Tractor, Inc. training course on Eddy 

Current Inspection on wing lower spar caps. 

BILLING CODE 4910–13–P 


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BILLING CODE 4910–13–C 

Special Flight Permit 

(l) Under 14 CFR 39.23, we are allowing 

special flight permits for the purpose of 

compliance with this AD under the following 

conditions: 

(1) Only operate in day visual flight rules 

(VFR). 

(2) Ensure that the hopper is empty. 

(3) Limit airspeed to 135 miles per hour 

(mph) indicated airspeed (IAS). 

(4) Avoid any unnecessary g-forces. 

(5) Avoid areas of turbulence. 

(6) Plan the flight to follow the most direct 

route. 

Alternative Methods of Compliance 

(AMOCs) 

(m) The Manager, Fort Worth or Los 

Angeles Airplane Certification Office (ACO), 

FAA, has the authority to approve AMOCs 

for this AD, if requested using the procedures 

found in 14 CFR 39.19. Before using any 

approved AMOC on any airplane to which 

the AMOC applies, notify your appropriate 

principal inspector (PI) in the FAA Flight 

Standards District Office (FSDO), or lacking 

a PI, your local FSDO. For AMOC approval, 

send information to ATTN: 

(1) For the airplanes that do not 

incorporate and never have incorporated 

Marburger winglets: Rob Romero, Aerospace 

Engineer, FAA, Fort Worth Airplane 

Certification Office, 2601 Meacham 

Boulevard, Fort Worth, Texas 76193–0150; 

telephone: (817) 222–5102; facsimile: (817) 

222–5960. 

(2) For airplanes that incorporate or have 

incorporated Marburger winglets: John Cecil, 

Aerospace Engineer, Los Angeles Aircraft 

Certification Office, FAA, 3960 Paramount 

Boulevard, Lakewood, California 90712; 


tjames on PRODPC61 with RULESER31MR09.000</GPH>
Federal Register / Vol. 74, No. 60 / Tuesday, March 31, 2009 / Rules and Regulations 14471 

telephone: (562) 627–5228; facsimile: (562) 

627–5210. 

(n) AMOCs approved for AD 2001–10–04, 

AD 2001–10–04 R1, or AD 2002–11–05 for 

the AT–400 series airplanes are not 

considered approved for this AD. 

(o) AMOCs approved for the repetitive 

inspection requirements of AD 2006–08–08 

are approved for this AD until the scheduled 

modification date required by this AD. That 

AMOC was included in AD 2006–08–08 and 

can be found in the docket at: http://

www.regulations.gov/fdmspublic/ 

component/main?main=DocketDetail&d

=FAA-2006-23646. 

Material Incorporated by Reference 

(p) You must use Snow Engineering Co. 

Drawing 21088, dated November 3, 2004; 

Snow Engineering Co. Process Specification 

197, page 1, revised June 4, 2002, pages 2 

through 4, dated February 23, 2001, and page 

5, dated May 3, 2002; and Snow Engineering 

Co. Service Letter 202, page 3, dated October 

16, 2000, to do the actions required by this 

AD, unless the AD specifies otherwise. 

(1) On April 21, 2006 (71 FR 19986, April 

19, 2006) the Director of the Federal Register 

approved the incorporation by reference of 

Snow Engineering Co. Drawing 21088, dated 

November 3, 2004; Snow Engineering Co. 

Process Specification 197, page 1, revised 

June 4, 2002, pages 2 through 4, dated 

February 23, 2001, and page 5, dated May 3, 

2002; and Snow Engineering Co. Service 

Letter 202, page 3, dated October 16, 2000, 

under 5 U.S.C. 552(a) and 1 CFR part 51. 

(2) For service information identified in 

this AD, contact Air Tractor, Incorporated, 

P.O. Box 485, Olney, Texas 76374; telephone: 

(940) 564–5616; facsimile: (940) 564–5612; 

Internet: http://www.airtractor.com; or 

Marburger Enterprises, Inc., 1227 Hillcourt, 

Williston, North Dakota 58801; telephone: 

(800) 893–1420 or (701) 774–0230; facsimile: 

(701) 572–2602. 

(3) You may review copies of the service 

information incorporated by reference for 

this AD at the FAA, Central Region, Office of 

the Regional Counsel, 901 Locust, Kansas 

City, Missouri 64106. For information on the 

availability of this material at the Central 

Region, call (816) 329–3768. 

(4) You may also review copies of the 

service information incorporated by reference 

for this AD at the National Archives and 

Records Administration (NARA). For 

information on the availability of this 

material at NARA, call (202) 741–6030, or go 

to: http://www.archives.gov/federal_register/ 

code_of_federal_regulations/ibr_

locations.html. 

Appendix 1 to AD 2006–08–08 R1 

The following provides procedures for 

determining the safe life for those Models 

AT–401, AT–401B, AT–402, AT–402A, and 

AT–402B airplanes that incorporate or have 

incorporated Marburger winglets. These 

winglets are installed following 

Supplemental Type Certificate (STC) No. 

SA00490LA. 

What if I removed the Marburger winglets 

prior to further flight after April 21, 2006 (the 

effective date of AD 2006–08–08) or prior to 

April 21, 2006 (the effective date of AD 2006– 

08–08)? 

1. Review your airplane’s logbook to 

determine your airplane’s time in service 

(TIS) with winglets installed per Marburger 

STC No. SA00490LA. This includes all time 

spent with the winglets currently installed 

and any previous installations where the 

winglet was installed and later removed. 

Example: A review of your airplane’s 

logbook shows that you have accumulated 

350 hours TIS since incorporating Marburger 

STC No. SA00490LA. Further review of the 

airplane’s logbook shows that a previous 

owner had installed the STC and later 

removed the winglets after accumulating 150 

hours TIS. Therefore, your airplane’s TIS 

with the winglets installed is 500 hours. 

If you determine that the winglet STC has 

never been incorporated on your airplane, 

then your safe life is presented in paragraph 

(c)(1) of this AD. Any future winglet 

installation will be subject to a reduced safe 

life per these instructions. 

2. Determine your airplane’s unmodified 

safe life from paragraph (c)(1) of this AD. 

Example: Your airplane is a Model AT– 

401B, SN 1022. From paragraph (c)(1) of this 

AD, the unmodified safe life of your airplane 

is 7,777 hours TIS. 

All examples from hereon will be based on 

the Model AT–401B, SN 1022 airplane. 

3. Determine the winglet usage factor from 

paragraph (c)(4) of this AD. 

Example: Again, your airplane is a Model 

AT–401B, SN 1022. From paragraph (c)(4) of 

this AD, your winglet usage factor is 1.1. 

4. Adjust the winglet TIS to account for the 

winglet usage factor. Multiply the winglet 

TIS (result of Step 1 above) by the winglet 

usage factor (result of Step 3 above). 

Example: Winglet TIS is 500 hours × a 

winglet usage factor of 1.1. The adjusted 

winglet TIS is 550 hours. 

5. Calculate the winglet usage penalty. 

Subtract the winglet TIS (result of Step 1 

above) from the adjusted winglet TIS (result 

of Step 4 above). 

Example: Adjusted winglet TIS ¥ the 

winglet TIS = winglet usage penalty. (550 

hours) ¥ (500 hours TIS) = (50 hours TIS). 

6. Adjust the safe life of your airplane to 

account for winglet usage. Subtract the 

winglet usage penalty (result of Step 5 above) 

result from the unmodified safe life from 

paragraph (c)(1) of this AD (result of Step 2 

above.). 

Example: Unmodified safe life ¥ winglet 

usage penalty = adjusted safe life. (7,777 

hours TIS) ¥ (50 hours TIS) = (7,727 hours 

TIS). 

7. If you remove the winglets from your 

airplane before further flight or no longer 

have the winglets installed on your airplane, 

the safe life of your airplane is the adjusted 

safe life (result of Step 6 above). Enter this 

number in paragraph (e)(1) of this AD and the 

airplane logbook. 

What if I have the Marburger winglet 

installed as of April 21, 2006 (the effective 

date of AD 2006–08–08) and plan to operate 

my airplane without removing the winglet? 

1. Review your airplane’s logbook to 

determine your airplane’s TIS without the 

winglets installed. 

Example: A review of your airplane’s 

logbook shows that you have accumulated 

1,500 hours TIS, including 500 hours with 

the Marburger winglets installed. Therefore, 

your airplane’s TIS without the winglets 

installed is 1,000 hours. 

2. Determine your airplane’s unmodified 

safe life from paragraph (c)(1) of this AD. 

Example: Your airplane is a Model AT– 

401B, SN 1022. From paragraph (c)(1) of this 

AD, the unmodified safe life of your airplane 

is 7,777 hours TIS. 

All examples from hereon will be based on 

the Model AT–401B, SN 1022 airplane. 

3. Determine the winglet usage factor from 

paragraph (c)(4) of this AD. 

Example: Again, your airplane is a Model 

AT–401B, SN 1022. From paragraph (c)(4) of 

this AD, your winglet usage factor is 1.1. 

4. Determine the potential winglet TIS. 

Subtract the TIS without the winglets 

installed (result of Step 1 above) from the 

unmodified safe life (result of Step 2 above). 

Example: Unmodified safe life ¥ TIS 

without winglets = Potential winglet TIS. 

(7,777 hours TIS) ¥ (1,000 hours TIS) = 

(6,777 hours TIS). 

5. Adjust the potential winglet TIS to 

account for the winglet usage factor. Divide 

the potential winglet TIS (result of Step 4 

above) by the winglet usage factor (result of 

Step 3 above). 

Example: Potential winglet TIS ÷ Winglet 

usage factor = Adjusted potential winglet 

TIS. (6,777 hours TIS) ÷ (1.1) = (6,155 hours 

TIS). 

6. Calculate the winglet usage penalty. 

Subtract the adjusted potential winglet TIS 

(result of Step 5 above) from the potential 

winglet TIS (result of Step 4 above). 

Example: Potential winglet TIS ¥ 

Adjusted potential winglet TIS = Winglet 

usage penalty. (6,777 hours TIS)¥ (6,155 

hoursTIS) = (622 hours TIS). 

7. Adjust the safe life of your airplane to 

account for the winglet installation. Subtract 

the winglet usage penalty (result of Step 6 

above) from the unmodified safe life from 

paragraph (c)(1) of this AD (the result of Step 

2 above). 

Example: Unmodified safe life ¥ Winglet 

usage penalty = Adjusted safe life. (7,777 

hours TIS) ¥ (622 hours TIS) = (7,155 hours 

TIS). 

8. Enter the adjusted safe life (result of Step 

7 above) in paragraph (e)(1) of this AD and 

the airplane logbook. 

What if I install or remove the Marburger 

winglet from my airplane in the future? 

If, at anytime in the future, you install or 

remove the Marburger winglet STC from your 

airplane, you must repeat the procedures in 

this Appendix to determine the airplane’s 

safe life. 

Issued in Kansas City, Missouri, on March 

24, 2009. 

John Colomy, 

Acting Manager, Small Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E9–7068 Filed 3–30–09; 8:45 am] 

BILLING CODE 4910–13–P 


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