# AD 2008-26-01: Overturn skid plate kit

- Type: Airworthiness directive
- Status: Current
- Products: Air Tractor AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-401A, AT-401B, AT-402, AT-402A, AT-402B and 6 more
- Effective: January 28, 2009
- Published: December 24, 2008, 73 FR 78944–78946
- Issued: December 9, 2008
- Issued as: Final rule
- Supersedes: [AD 2008-11-17](https://openairdocs.org/ad/2008-11-17)
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-15767
- Docket: FAA-2008-1120 (https://www.regulations.gov/docket/FAA-2008-1120)
- Project: 2008-CE-064-AD
- Registered aircraft: 1,692 may be affected, by airframe or engine model (OpenAirDocs)
- Official PDF: https://openairdocs.org/files/sha256/10/8f/108fc88656e1d868a1410de8f51bbfb25d86940ff64e72fd485c37fc436d0517 (from https://www.govinfo.gov/content/pkg/FR-2008-12-24/pdf/E8-29568.pdf)
- Federal Register: https://www.federalregister.gov/documents/2008/12/24/E8-29568/airworthiness-directives-air-tractor-inc-models-at-200-at-300-at-400-at-500-at-600-and-at-800-series
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5FBE5969D4AED92C8625752900558979.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/2008-26-01

## Summary

We are adopting a new airworthiness directive (AD) to supersede AD 2008-11-17, which applies to certain Air Tractor, Inc. Models AT-200, AT-300, AT-400, AT-500, AT-600, and AT-800 series airplanes. AD 2008-11-17 currently requires you to install an overturn skid plate kit or a modification to the overturn skid plate already installed. Since we issued AD 2008-11-17, the manufacturer has notified us that Model AT-401B airplanes also need a modification to the overturn skid plate. Consequently, this AD would retain the actions of AD 2008-11-17 and add the requirement to modify the overturn skid plate installed on Model AT-401B airplanes. We are issuing this AD to prevent the front and rear connections of the overturn skid plate to the airplane from breaking, which could allow foreign debris to enter the cockpit during an airplane overturn. This condition, if not corrected, could lead to pilot injury.

## The airworthiness directive

### 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:

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by removing Airworthiness Directive (AD) 2008-11-17, Amendment 39-15540 (73 FR 31351, June 2, 2008), and adding the following new AD:

2008-26-01 Air Tractor, Inc.: Amendment 39-15767; Docket No. FAA-2008-1120; Directorate Identifier 2008-CE-064-AD.

### (a) Effective Date

  (a) This AD becomes effective on January 28, 2009.

### (b) Affected ADs

  (b) This AD supersedes AD 2008-11-17, Amendment 39-15540.

### (c) Applicability

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


| Group 1 models | Serial Nos. |
| --- | --- |
| AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-401A, AT-402, AT-402A, and AT-402B | -0001 through -1196. |
| AT-501, AT-502, AT-502A, and AT-502B | -0001 through -2620. |
| AT-602 | -0337 through -1153. |
| AT-802A | -0003 through -0282. |


| Group 2 models | Serial Nos. |
| --- | --- |
| AT-401B | -0952 through -1196. |

### (d) Unsafe Condition

  (d) Since we issued AD 2008-11-17, the manufacturer has notified us that Model AT-401B airplanes also need a modification to the overturn skid plane. Consequently, this AD retains the actions of AD 2008-11-17 and adds the requirement to modify the overturn skid plate installed on Model AT-401B airplanes. We are issuing this AD to prevent the front and rear connections of the overturn skid plate to the airplane from breaking, which could allow foreign debris to enter the cockpit during an airplane overturn. This condition, if not corrected, could lead to pilot injury.

### (e) Compliance

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


| Actions | Compliance | Procedures |
| --- | --- | --- |
| (1) For Group 1 airplanes: If overturn skid plate part number (P/N) 11411-1-500 or an FAA-approved equivalent P/N is already installed then install P/N 11411-1-501 modification kit | Within the next 180 days after July 7, 2008 (the effective date of AD 2008-11-17) | Follow Snow Engineering Co. Service Letter #97, revised November 7, 2007; or Snow Engineering Co. Service Letter #97, revised September 19, 2008. |
| (2) For Group 1 airplanes: If there is no overturn skid plate installed, then install overturn skid plate kit P/N 11411-1-502 or an FAA-approved equivalent part number | Within the next 180 days after July 7, 2008 (the effective date of AD 2008-11-17) | Follow Snow Engineering Co. Service Letter #97, revised November 7, 2007; or Snow Engineering Co. Service Letter #97, revised September 19, 2008. |
| (3) For Group 2 airplanes: Install P/N 11411-1-501 modification kit | Within the next 180 days after January 28, 2009 (the effective date of this AD) | Follow Snow Engineering Co. Service Letter #97, revised September 19, 2008. |

### (f) Alternative Methods of Compliance (AMOCs)

  (f) The Manager, Fort Worth Airplane Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Andy McAnaul, Aerospace Engineer, ASW-150, FAA San Antonio MIDO-43, 10100 Reunion Pl., Ste. 650, San Antonio, Texas 78216; telephone: (210) 308-3365; fax: (210) 308-3370. 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.

### (h) Material Incorporated by Reference

  (h) You must use Snow Engineering Co. Service Letter #97, revised November 7, 2007; or Snow Engineering Co. Service Letter #97, revised September 19, 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 Snow Engineering Co. Service Letter #97, revised September 19, 2008, under 5 U.S.C. 552(a) and 1 CFR part 51.

  (2) On July 7, 2008 (73 FR 31351, June 2, 2008), the Director of the Federal Register approved the incorporation by reference of Snow Engineering Co. Service Letter #97, revised November 7, 2007.

  (3) For service information identified in this AD, contact Air Tractor Inc., P.O. Box 485, Olney, Texas 76374; telephone: (940) 564-5616; fax: (940) 564-5612; e-mail: airmail@airtractor.com; Internet: http://www.airtractor.com.

  (4) 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.

  (5) 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.

## Rule preamble

### Dates

This AD becomes effective on January 28, 2009.

On January 28, 2009, the Director of the Federal Register approved the incorporation by reference of Snow Engineering Co. Service Letter #97, revised September 19, 2008, listed in this AD.

As of July 7, 2008 (73 FR 31351, June 2, 2008), the Director of the Federal Register approved the incorporation by reference of Snow Engineering Co. Service Letter #97, revised November 7, 2007, listed in this AD.

### Addresses

For service information identified in this AD, contact Air Tractor Inc., P.O. Box 485, Olney, Texas 76374; telephone: (940) 564-5616; fax: (940) 564-5612; e-mail: airmail@airtractor.com; Internet: http://www.airtractor.com.

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-2008-1120; Directorate Identifier 2008-CE-064-AD.

### For further information contact

Andy McAnaul, Aerospace Engineer, ASW-150, FAA San Antonio MIDO-43, 10100 Reunion Pl., Ste. 650, San Antonio, Texas 78216; telephone: (210) 308-3365; fax: (210) 308-3370.

### Discussion

On October 14, 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, Inc. Models AT-200, AT-300, AT-400, AT-500, AT-600, and AT-800 series airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on October 23, 2008 (73 FR 63096). The NPRM proposed to supersede AD 2008-11-17 with a new AD that would retain the actions of AD 2008-11-17 and add the requirement to modify the overturn skid plate installed on Model AT-401B airplanes.

### Comments

We provided the public the opportunity to participate in developing this AD. We received no comments on the proposal or on the determination of the cost to the public.

### 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.

### Costs of Compliance

We estimate that this AD affects 1,309 airplanes in the U.S. registry.

In determining the total cost on U.S. operators, we presume all airplanes in the U.S. fleet have an overturn skid plate installed (as required by AD 2002-25-09) and the only cost is to incorporate the modification kit P/N 11411-1-501. We estimate the following costs to do the modification of installing the overturn skid plate modification kit P/N 11411-1-501 to those planes that currently have the overturn skid plate installed:


| Labor cost | Parts cost | Total cost per airplane | Total cost on U.S. operators |
| --- | --- | --- | --- |
| 2 work-hours × $80 per hour = $160 | $42 | $202 | $264,418 |

### 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-2008-1120; Directorate Identifier 2008-CE-064-AD” in your request.

## Affected data sheets (3) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A17SW](https://openairdocs.org/tcds/A17SW): Air Tractor Inc.; names 10 of 13 models: AT-402B, AT-401B, AT-501, AT-502A, AT-402A, AT-402, AT-502B, AT-401…
- [TCDS A9SW](https://openairdocs.org/tcds/A9SW): Air Tractor Inc.; names 6 of 6 models: AT-301, AT-400, AT-250, AT-300, AT-302, AT-400A
- [TCDS A19SW](https://openairdocs.org/tcds/A19SW): Air Tractor Inc.; names 2 of 3 models: AT-602, AT-802A

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 1,692 (1,692 by airframe model, 0 by engine model)
- Makers: Air Tractor 1,692

Models with the most aircraft:

- [Air Tractor AT-802A](https://openairdocs.org/model/air-tractor-at-802a): 578 aircraft (airframe model)
- [Air Tractor AT-502B](https://openairdocs.org/model/air-tractor-at-502b): 328 aircraft (airframe model)
- [Air Tractor AT-602](https://openairdocs.org/model/air-tractor-at-602): 245 aircraft (airframe model)
- [Air Tractor AT-502A](https://openairdocs.org/model/air-tractor-at-502a): 95 aircraft (airframe model)
- [Air Tractor AT-301](https://openairdocs.org/model/air-tractor-at-301): 83 aircraft (airframe model)
- [Air Tractor AT-502](https://openairdocs.org/model/air-tractor-at-502): 78 aircraft (airframe model)
- [Air Tractor AT-402B](https://openairdocs.org/model/air-tractor-at-402b): 77 aircraft (airframe model)
- [Air Tractor AT-401](https://openairdocs.org/model/air-tractor-at-401): 50 aircraft (airframe model)
- [Air Tractor AT-402A](https://openairdocs.org/model/air-tractor-at-402a): 48 aircraft (airframe model)
- [Air Tractor AT-402](https://openairdocs.org/model/air-tractor-at-402): 35 aircraft (airframe model)
- [Air Tractor AT-400](https://openairdocs.org/model/air-tractor-at-400): 30 aircraft (airframe model)
- [Air Tractor AT-400A](https://openairdocs.org/model/air-tractor-at-400a): 19 aircraft (airframe model)
- [Air Tractor AT-401B](https://openairdocs.org/model/air-tractor-at-401b): 17 aircraft (airframe model)
- [Air Tractor AT-501](https://openairdocs.org/model/air-tractor-at-501): 4 aircraft (airframe model)
- [Air Tractor AT-300](https://openairdocs.org/model/air-tractor-at-300): 2 aircraft (airframe model)
- [Air Tractor AT-302](https://openairdocs.org/model/air-tractor-at-302): 1 aircraft (airframe model)
- [Air Tractor AT-401A](https://openairdocs.org/model/air-tractor-at-401a): 1 aircraft (airframe model)
- [Air Tractor AT-250](https://openairdocs.org/model/air-tractor-at-250): 1 aircraft (airframe model)

All 19 models: https://openairdocs.org/ad/2008-26-01/models.md
Every aircraft: https://openairdocs.org/ad/2008-26-01/aircraft.md

## Related documents

- [AD 2008-11-17](https://openairdocs.org/ad/2008-11-17) (historical): Overturn skid plate in the cockpit area · Air Tractor AT-250, AT-300, AT-301 and 14 more. Effective Jul 7, 2008. Replaced by this AD
- [Proposed rule FAA-2008-1120](https://openairdocs.org/proposed/FAA-2008-1120): Notice of proposed rulemaking (NPRM), published Oct 23, 2008

Its text cites no advisory circulars or STCs.

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