E7-20862. Airworthiness Directives; Cessna Aircraft Company Models 172R and 172S Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Cessna Aircraft Company (Cessna) Models 172R and 172S. This proposed AD would require you to inspect the fuel return line assembly for chafing; replace the fuel return line assembly if chafing is found; and inspect the clearance between the fuel return line assembly and both the right steering tube assembly and the airplane structure, adjusting as necessary. This proposed AD results from reports of chafed fuel return line assemblies, which were caused by the fuel return line assembly rubbing against the right steering tube assembly during full rudder pedal actuation. We are proposing this AD to detect and correct chafing of the fuel return line assembly, which could result in fuel leaking under the floor and fuel vapors entering the cabin. This condition could lead to fire under the floor or in the cabin area.

DATES:

We must receive comments on this proposed AD by December 24, 2007.

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 Cessna Aircraft Company, Product Support, P.O. Box 7706, Wichita, Kansas 67277; telephone: [phone]; fax: [phone].

FOR FURTHER INFORMATION CONTACT:

Trenton Shepherd, Aerospace Engineer, 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone: [phone]; fax: [phone]; e-mail: [e-mail].

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-2007-29138; Directorate Identifier 2007-CE-073-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

We have received four reports of fuel return line assembly chafing in Cessna Models 172R and 172S airplanes. The reports indicated the fuel return line assembly rubbed against the right steering tube assembly during full rudder pedal actuation and caused the chafing.

This condition, if not corrected, could result in fuel leaking under the cabin floor and fuel vapors entering the cabin. This condition could lead to fire under the floor or in the cabin area.

Relevant Service Information

We have reviewed Cessna Mandatory Service Bulletin SB07-28-01, dated June 18, 2007. The service information describes the following procedures:

• Inspecting the fuel return line assembly;
• Replacing the fuel return line assembly if chafing is found; and
• Inspecting the clearance between the fuel return line assembly and both the right steering tube assembly and the airplane structure, adjusting as necessary.

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 require you to detect and correct chafing of the fuel vent line assembly.

Differences Between This Proposed AD and the Service Information

The service information permits tube damage up to a depth of 0.0035 inch. There is no known method to accurately measure the thickness damage on a tube. We propose to require replacement of the fuel return line assembly if any damage is found.

If no chafing is found in the inspection of the fuel return line assembly, the service information does not require inspection for clearance around the fuel return line assembly. We propose to inspect the clearance between the fuel return line assembly and both the right steering tube assembly and airplane structure, for all applicable aircraft.

The service information does not specify a minimum clearance requirement between the fuel return line assembly and the right steering tube assembly, only that the fuel return line assembly does not touch either the right steering tube assembly or the airplane structure. We propose to require a minimum of 0.5 inch of clearance between the fuel return line assembly and both the right steering tube assembly and the airplane structure, during full rudder pedal actuation.

The requirements of this proposed AD, if adopted as a final rule, would take precedence over the provisions in the service information.

Costs of Compliance

We estimate that this proposed AD would affect 928 airplanes in the U.S. registry.

We estimate the following costs to do the proposed inspection:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
1 work-hour × $80 per hour = $80	N/A	$80	$74,240

We estimate the following costs to do any necessary replacements that would be required based on the results of the proposed inspection. We have no way of determining the number of airplanes that may need this replacement:

Labor cost	Parts cost	Total cost per airplane
0.5 work-hour × $80 per hour = $40	$123	$163

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 adding the following new AD:

Cessna Aircraft Company: Docket No. FAA-2007-29138; Directorate Identifier 2007-CE-073-AD.

Comments Due Date

(a) We must receive comments on this airworthiness directive (AD) action by December 24, 2007.

Affected ADs

(b) None.

Applicability

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

Models	Serial No.
172R	17281188 through 17281390.
172S	172S9491 through 172S10489.

Unsafe Condition

(d) This AD results from reports of chafed fuel return line assemblies caused by the fuel return line assembly rubbing against the right steering tube assembly during full rudder pedal actuation. We are issuing this AD to detect and correct chafing of the fuel return line assembly, which could result in fuel leaking under the cabin floor and fuel vapors entering the cabin. This condition could lead to fire under the floor or in the cabin area.

Compliance

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

Note:

The requirements of this AD take precedence over the actions required in the service information.

Actions	Compliance	Procedures
(1) Inspect the fuel return line assembly (Cessna part number (P/N) 0500118-49 or FAA-approved equivalent P/N) for chafing	Within the next 100 hours time-in-service (TIS) after the effective date of this AD or within the next 12 months after the effective date of this AD, whichever occurs first	Follow Cessna Service Bulletin SB07-28-01, dated June 18, 2007.
(2) If chafing is found in the inspection required in paragraph (e)(1) of this AD, replace the fuel return line assembly (Cessna P/N 0500118-49 or FAA-approved equivalent P/N)	Before further flight after the inspection required in paragraph (e)(1) of this AD where evidence of chafing was found	Follow Cessna Service Bulletin SB07-28-01, dated June 18, 2007.
(3) Inspect for a minimum clearance of 0.5 inch between the following parts throughout the entire range of copilot rudder pedal travel and adjust the clearance as necessary:	Before further flight after: (A) The inspection required in paragraph (e)(1) of this AD if no chafing is found; or (B) The replacement required in paragraph (e)(2) of this AD.	Follow paragraph 6 of the Instructions section of Cessna Service Bulletin SB07-28-01, dated June 18, 2007. This AD requires a minimum clearance of 0.5 inch.
(i) The fuel return line assembly (Cessna P/N 0500118-49 or FAA-approved equivalent P/N) and the steering tube assembly (Cessna P/N MC0543022-2C); and
(ii) The fuel return line assembly (Cessna P/N 0500118-49 or FAA-approved equivalent P/N) and the airplane structure.

Alternative Methods of Compliance (AMOCs)

(f) The Manager, Wichita Aircraft Certification Office (ACO), 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: Trenton Shepherd, Aerospace Engineer, 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone: [phone]; fax: [phone]; e-mail: [e-mail]. 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.

Related Information

(g) To get copies of the service information referenced in this AD, contact Cessna Aircraft Company, Product Support, P.O. Box 7706, Wichita, Kansas 67277; telephone: [phone]; fax: [phone]. 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 Docket No. FAA-2007-29138; Directorate Identifier 2007-CE-073-AD.

Issued in Kansas City, Missouri, on October 17, 2007.

David R. Showers,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.