02-15937. Airworthiness Directives; Air Tractor, Inc. Models AT-300, AT-301, AT-302, AT-400, and AT-400A Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) that applies to all Air Tractor, Inc. (Air Tractor) Models AT-300, AT-301, AT-302, and AT-400A airplanes that have aluminum spar caps; certain Air Tractor Models AT-400 airplanes that have aluminum spar caps; and all Models AT-300 and AT-301 airplanes that have aluminum spar caps and are or have been converted to turbine power. This AD requires you to inspect (one-time) the wing centerline splice joint for cracks and, if any crack is found, replace the affected wing spar lower cap. This AD also requires you to report the results of the inspection to the Federal Aviation Administration (FAA) and replace the wing spar lower caps after a certain amount of usage. This AD is the result of an incident on one of the affected airplanes where the wing separated from the airplane. Preliminary reports indicate that fatigue caused the lower aluminum spar cap to fail across the 3/8-inch bolt hole (6.5 inches outboard of the fuselage centerline in the centersplice connection). The actions specified by this AD are intended to detect and correct cracks in the wing centerline splice joint. If not detected and corrected, these cracks could eventually result in the wing separating from the airplane during flight.

DATES:

This AD becomes effective on July 9, 2002.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulation as of July 9, 2002.

The FAA must receive any comments on this rule on or before August 23, 2002.

ADDRESSES:

Submit comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2002-CE-22-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. You may view any comments at this location between 8 a.m. and 4 p.m., Monday through Friday, except Federal holidays. You may also send comments electronically to the following address: [e-mail]. Comments sent electronically must contain “Docket No. 2002-CE-22-AD” in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Word 97 for Windows or ASCII text.

You may get the service information referenced in this AD from Air Tractor, Inc., P.O. Box 485, Olney, Texas 76374. You may view this information at FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2002-CE-22-AD, 901 Locust, Room 506, Kansas City, Missouri 64106; or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Andy McAnaul, Aerospace Engineer, FAA, Fort Worth Airplane Certification Office, 2601 Meacham Boulevard, Fort Worth, Texas 76193-0150; telephone: [phone]; facsimile: [phone].

SUPPLEMENTARY INFORMATION:

Discussion

What Events Have Caused This AD?

Recently, the wing of an Air Tractor Model AT-400A separated from the airplane during flight. Investigation reveals that the right-hand lower spar cap failed due to fatigue at the 3/8-inch outboard bolt, which is located 6.5 inches outboard of the fuselage centerline.

The following airplanes have a similar type design to that of the accident airplane:

—All Models AT-300, AT-301, AT-302, and AT-400A airplanes that have aluminum spar caps;

—Air Tractor Models AT-400 airplanes, serial numbers 400-0244 through 400-0415, that have aluminum spar caps; and

—All Models AT-300 and AT-301 airplanes that have aluminum spar caps and are or have been converted to turbine power.

In addition, some airplanes have had Snow Engineering Co. Service Letter #55 incorporated. When incorporated, the affected area would be (1) the left and right side second outermost 7/16-inch boltholes, which are located 5.38 inches from centerline; and (2) the left and right side outermost 3/8-inch boltholes, which are located 6.5 inches outboard from centerline.

What Are the Consequences if the Condition is Not Corrected?

If not detected and corrected in a timely manner, cracks in the wing centerline splice joint could eventually result in the wing separating from the airplane during flight.

Is There Service Information That Applies to This Subject?

Air Tractor has issued the following:

—Snow Engineering Co. Process Specification 197, dated February 23, 2001; Revised May 1, 2002, and Revised May 3, 2002, which specify procedures for accomplishing an eddy current inspection of the wing centerline splice joint on the affected airplanes; and

—Snow Engineering Co. Service Letter #220, dated May 3, 2002, which specifies the procedures for gaining access to perform the eddy current inspection.

The FAA's Determination and an Explanation of the Provisions of this AD

What Has FAA Decided?

The FAA has reviewed all available information and determined that:

—The unsafe condition referenced in this document exists or could develop on other Air Tractor Models AT-300, AT-301, AT-302, AT-400, and AT-400A airplanes of the same type design;

—A one-time eddy current inspection should be accomplished on these airplanes to detect and correct cracks in the wing centerline splice joint;

—The wing lower spar caps should be replaced at a certain time; and

—Final rule; request for comments (immediately adopted rule) AD action should be taken to address this condition.

What Does This AD Require?

This AD requires you to inspect (one-time) the wing centerline splice joint for cracks and, if any crack is found, replace the affected wing spar lower cap. This AD also requires you to report the results of the inspection to FAA and replace the wing spar lower caps after a certain amount of usage.

You must accomplish these actions in accordance with the previously-referenced service information.

We will evaluate the information received from the reporting requirement of this AD to determine whether additional rulemaking action should be taken. This could include repetitive inspections, parts replacement, modifications, or no further action.

In preparation of this rule, we contacted type clubs and aircraft operators to obtain technical information and information on operational and economic impacts. We have included, in the rulemaking docket, a discussion of information that may have influenced this action.

Will I have the Opportunity To Comment Prior to the Issuance of the Rule?

Because the unsafe condition described in this document could result in the wing separating from the airplane during flight, we find that notice and opportunity for public prior comment are impracticable. Therefore, good cause exists for making this amendment effective in less than 30 days.

Comments Invited

How Do I Comment on This AD?

Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, FAA invites your comments on the rule. You may submit whatever written data, views, or arguments you choose. You need to include the rule's docket number and submit your comments to the address specified under the caption ADDRESSES. We will consider all comments received on or before the closing date specified above. We may amend this rule in light of comments received. Factual information that supports your ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether we need to take additional rulemaking action.

Are There Any Specific Portions of the AD I Should Pay Attention to?

We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. You may view all comments we receive before and after the closing date of the rule in the Rules Docket. We will file a report in the Rules Docket that summarizes each FAA contact with the public that concerns the substantive parts of this AD.

How Can I be Sure FAA Receives My Comment?

If you want us to acknowledge the receipt of your comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 2002-CE-22-AD.” We will date stamp and mail the postcard back to you.

Regulatory Impact

Does This AD Impact Various Entities?

These regulations 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. Therefore, FAA has determined that this final rule does not have federalism implications under Executive Order 13132.

Does This AD Involve a Significant Rule or Regulatory Action?

We have determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a significant regulatory action under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket (otherwise, an evaluation is not required). A copy of it, if filed, may be obtained from the Rules Docket.

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. FAA amends § 39.13 by adding a new airworthiness directive (AD) to read as follows:

2002-13-02 Air Tractor, Inc.: Amendment 39-12789; Docket No. 2002-CE-22-AD.

(a) What airplanes are affected by this AD? This AD applies to the following airplanes that are certificated in any category:

(1) Models AT-300, AT-301, AT-302, and AT-400A airplanes, all serial numbers, that have aluminum spar caps;

(2) Models AT-400 airplanes, serial numbers 400-0244 through 400-0415, that have aluminum spar caps; and

(3) Models AT-300 and AT-301 airplanes, all serial numbers that have aluminum spar caps and are or have been converted to turbine power.

(b) Who must comply with this AD? Anyone who wishes to operate any airplane identified in paragraph (a)(1), (a)(2), or (a)(3) of this AD must comply with this AD.

(c) What problem does this AD address? The actions specified by this AD are intended to detect and correct cracks in the wing centerline splice joint. If not detected and corrected, these cracks could eventually result in the wing separating from the airplane during flight.

(d) What must I do to address this problem? To address this problem, you must accomplish the following actions:

Actions	Compliance	Procedures
(1) Inspect, using eddy current inspection methods, the wing centerline splice joint. The particular inspection area depends on whether Snow Engineering Service Letter #55 is incorporated. Specifics are included in the service information. The inspection must be accompanied by one of the following: (i) a Level 2 or Level 3 inspector that is certified for eddy-current inspection using the guidelines established by the American Society for Nondestructive Testing or MIL-STD-410; or (ii) A person authorized to perform AD work who has completed and passed the Air Tractor, Inc. training course on Eddy Current Inspection on wing lower spar caps	For affected airplanes (turbine-powered or piston engine-powered) with at least one wing spar lower cap having 6,990 or more hours time-in-service (TIS) as of the effective date of this AD: Inspect within the next 10 hours TIS after July 9, 2002 (the effective date of this AD), unless already accomplished after accumulating 6,000 hours TIS; For affected piston engine-powered airplanes with at least one wing spar lower cap having less than 6,990 hours TIS as of the effective date of this AD: Inspect upon the accumulation of 6,000 hours TIS or within the next 50 hours TIS after July 9, 2002 (the effective date of this AD), whichever occurs later, unless already accomplished after accumulating 6,000 hours TIS; or For affected turbine-powered aiplanes with at least one wing spar lower cap having less than 6,999 hours TIS as of the effective day of this AD. Upon the accumulation of 4,000 hours TIS or within the next 50 hours TIS after July 9, 2002 (the effective date of this AD), whichever occurs later, unless already accomplished after accumlating 4,000 hours TIS	Inspect in accordance with Snow Engineering Co. Service Letter #220, dated May 3, 2002; and Snow Enigneering Co. Process Specification 197, dated February 23, 2001; Revised May 1, 2002, or Revised May 3, 2002.
(2) If cracks are found during the inspection required by paragraph (d)(1) of this AD, replace the affected wing spar lower cap	Prior to further flight after the inspection required by paragraph (d)(1) of this AD	In accordance with the instructions in the applicable maintenance manual.
(3) Report the results of the inspection in paragraph (d)(1) of this AD to FAA. The Office of Management and Budget (OMB) approved the information collection requirements contained in this regulation under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and assigned OMB Control Number 2120-0056	If the inspection is accomplished after the effective date of this AD: Within 10 days after the inspection required in paragraph (d)(1) of this AD; or If the inspection was already accomplished prior to the effective date of this AD: within the next 10 days after July 9, 2002 (the effective date of this AD)	Submit the form (Figure 1 of paragraph (d)(3) of this AD) to FAA, Fort Worth Airplane Certification Office, 2601 Meacham Boulevard, Fort Worth, Texas 76193-0150; telephone: [phone]; facsimile: [phone].
(4) Replace each wing spar lower cap	Replace each lower cap upon the accumulation of 7,000 hours TIS on each wing spar lower cap or within the next 200 hours TIS after July 9, 2002 (the effective date of this AD), whichever occurs later	In accordance with instructions in the applicable maintenance manual.

(e) Can I comply with this AD in any other way? You may use an alternative method of compliance or adjust the compliance time if:

(1) Your alternative method of compliance provides an equivalent level of safety; and

(2) The Manager, Fort Worth Airplane Certification Office (ACO), approves your alternative. Submit your request through an FAA Principal Maintenance Inspector. The inspector may add comments before sending it to the Manager, Fort Worth ACO.

Note:

This AD applies to each airplane identified in paragraphs (a)(1), (a)(2), and (a)(3) of this AD, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if you have not eliminated the unsafe condition, specific actions you propose to address it.

(f) What if I need to fly the airplane to another location to comply with this AD? The FAA can issue a special flight permit under sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate your airplane to a location where you can accomplish the requirements of this AD provided that the following is adhered to:

(1) Operate in day visual flight rules (VFR) only.

(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.

(g) Are any service bulletins incorporated into this AD by reference? Replacement and inspection actions required by this AD must be done in accordance with Snow Engineering Co. Service Letter #220, dated May 3, 2002; and Snow Engineering Co. Process Specification 197, dated February 23, 2001, Revised May 1, 2002, or Revised May 3, 2002. The Director of the Federal Register approved this incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 51. You can get copies from Air Tractor, Inc., P.O. Box 485, Olney, Texas 76374. You may view copies at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

(h) When does this amendment become effective? This amendment becomes effective on July 9, 2002.

Issued in Kansas City, Missouri, on June 18, 2002.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft Certification Service.