E8-18228. Airworthiness Directives; Allied Ag Cat Productions, Inc. G-164 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to supersede Airworthiness Directive (AD) 78-08-09, which applies to certain Allied Ag Cat Productions, Inc. (formerly Grumman-American) Models G-164, G-164A, and G-164B airplanes. AD 78-08-09 currently requires repetitively inspecting the interior and the exterior of the main tubular spar of the rudder assembly for corrosion, taking necessary corrective action if corrosion is found, and applying corrosion protection. Since we issued AD 78-08-09, the rudder main tubular spar failed on a later production airplane. Consequently, this proposed AD would retain the actions required in AD 78-08-09 and expand the applicability to include all G-164 series airplanes. We are proposing this AD to detect and correct corrosion in the rudder main tubular spar, which could result in failure of the weld to the main spar tube. This failure could lead to loss of directional control.

DATES:

We must receive comments on this proposed AD by October 6, 2008.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Grumman American Aviation Corporation, P.O. Box 2206, Savannah, Georgia 31402; telephone: [phone].

FOR FURTHER INFORMATION CONTACT:

Andy McAnaul, Aerospace Engineer, ASW-150, FAA San Antonio MIDO-43, 10100 Reunion Place, Suite 650, San Antonio, Texas 78216, phone: [phone], fax: [phone].

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-2008-0854; Directorate Identifier 2008-CE-050-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://www.regulations.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

Excessive corrosion on the main tubular spar, part number A1203-11, of the rudder assembly resulting from moisture accumulating in the lower internal cavity on Allied Ag Cat Productions, Inc. (formerly Grumman-American) Models G-164, G-164A, and G-164B airplanes caused us to issue AD 78-08-09, Amendment 39-3191. AD 78-08-09 currently requires the following on certain Models G-164, G-164A, and G-164B airplanes:

• Repetitively inspecting the rudder main tubular spar for corrosion;
• Repairing any corrosion found; and
• Applying corrosion protection.

AD 78-08-09 applies only to early production Allied Ag Cat airplanes. In March 2008, the rudder main tubular spar failed on a Model G164B airplane, serial number 586B (not affected by AD 78-08-09). The spar failed where the lower fitting is welded to the main tube. Investigation revealed that the failure was a result of severe internal corrosion caused by moisture trapped in the lower internal cavity of the spar tube.

AD 78-08-09 does not establish a way to identify affected rudders. It is a common practice to repair agricultural airplanes with repaired or used serviceable parts from other sources, or using removed parts from other airplanes. Based on the lack of traceability, rudders affected by AD 78-08-09 are potentially being installed on Allied Ag Cat model airplanes not affected by AD 78-08-09. Also, many rudders have been modified to “tall” rudders by supplemental type certificate (STC), or replaced with aftermarket rudders, which all have the same corrosion susceptible design as the original earlier production rudders.

This condition, if not detected and corrected, could result in failure of the rudder main spar tubular spar. This failure could lead to loss of directional control.

Relevant Service Information

We have reviewed Grumman American Aviation Corporation Ag-Cat Service Bulletin No. 61, dated June 6, 1977.

The service information specifies:

• Repetitively inspecting the main tubular spar for corrosion;
• Repairing any corrosion found; and
• Applying corrosion protection.

FAA's Determination and Requirements of the 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 78-08-09 with a new AD that would retain the actions required in AD 78-08-09 and expand the applicability to include all G-164 series airplanes. This proposed AD would require you to use the service information described previously to perform these actions.

Costs of Compliance

We estimate that this proposed AD would affect 2,700 airplanes in the U.S. registry.

We estimate the following costs to do the proposed inspections:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
4 work-hours × $80 per hour = $320	Not applicable	$320	$864,000

We have no way of determining the cost of repairs or parts replacement or the number of airplanes that may require repair or part replacement based on the result of the proposed inspections.

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://www.regulations.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 [phone]) 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by removing Airworthiness Directive (AD)

78-08-09, Amendment 39-3191, and adding the following new AD:

Allied Ag Cat Productions, Inc.: Docket No. FAA-2008-0854; Directorate Identifier 2008-CE-050-AD.

Comments Due Date

(a) We must receive comments on this airworthiness directive (AD) action by October 6, 2008.

Affected ADs

(b) This AD supersedes AD 78-08-09, Amendment 39-3191.

Applicability

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

Models

G-164, G-164A, G-164B, G-164B with 73″, G-164B-15T, G-164B-34T, G-164B-20T, G-164C, G-164D, and G-164D with 73″ wing gap.

Unsafe Condition

(d) This AD results from a report of the rudder main tubular spar failing on a later production airplane. We are issuing this AD to detect and correct corrosion in the rudder main tubular spar, which could result in failure of the weld to the main spar tube. This failure could lead to loss of directional control.

Compliance

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

Actions	Compliance	Procedures
(1) Drill an access hole and do a borescope visual inspection of the lower end internal cavity of the rudder main spar tube for corrosion and do a visual inspection of the exterior of the rudder main spar tube for corrosion	(i) For airplanes previously affected by AD 78-08-09: Initially inspect within the next 60 months after the last inspection required in AD 78-08-09 or within the next 30 days after the effective date of this AD, whichever occurs later. Repetitively inspect thereafter at intervals not to exceed 60 calendar months	Following Steps 1 through 3 of Grumman American Aviation Corporation Ag-Cat Service Bulletin No. 61, dated June 6, 1977.
	(ii) For airplanes not previously affected by AD 78-08-09: Initially inspect within the next 30 days after the effective date of this AD. Repetitively inspect thereafter at intervals not to exceed 60 calendar months
(2) If corrosion is found during any inspection required in paragraph (e)(1) of this AD, repair in accordance with Advisory Circular 43.13-1B or equivalent, or replace the damaged part(s)	Before further flight after any inspection in which corrosion is found	As specified in Steps 5 and 6 of Grumman American Aviation Corporation Ag-Cat Service Bulletin No. 61, dated June 6, 1977. Following Advisory Circular 43.13-1B or equivalent, and an FAA-approved procedure. The appropriate maintenance manual contains these procedures.
(3) After each inspection and repair or replacement required in this AD, corrosion protect the spar tube internal cavity by filling with warm, raw linseed oil, Paralketone, or CRC3 (LPS Heavy Duty Rust Inhibitor Type 3), or suitable equivalent protector for alloy steel, and allow to drain. Seal access hole with Scotch caulking compound, or suitable silicone based sealant, or equivalent	Before further flight after any inspection required in paragraph (e)(1) of this AD and after any repair or replacement required in paragraph (e)(2) of this AD	As specified in Step 4 of Grumman American Aviation Corporation Ag-Cat Service Bulletin No. 61, dated June 6, 1977.
(4) Verify rigging check of the rudder	Before further flight after any inspection required in paragraph (e)(1) of this AD and after any repair or replacement required in paragraph (e)(2) of this AD	Following an FAA-approved procedure. The appropriate maintenance manual contains these procedures.
(5) Only install a rudder that has been inspected as specified in paragraph (e)(1) of this AD, is free of corrosion, and has had the corrosion protection applied and sealed as specified in paragraph (e)(3) of this AD	As of the next 30 days after the effective date of this AD	Not applicable.

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 Place, Suite 650, San Antonio, Texas 78216, phone: [phone]; fax: [phone]. 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.

(g) AMOCs approved for AD 78-08-09 are not approved for this AD.

Related Information

(h) To get copies of the service information referenced in this AD, contact Grumman American Aviation Corporation, P.O. Box 2206, Savannah, Georgia 31402. 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.

Issued in Kansas City, Missouri, on August 1, 2008.

James E. Jackson,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.