2010-7024. Airworthiness Directives; Cessna Aircraft Company Model 525A Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to supersede Airworthiness Directive (AD) 2009-24-13, which applies to certain Cessna Aircraft Company (Cessna) Model 525A airplanes. AD 2009-24-13 currently requires you to repetitively inspect the thrust attenuator paddle assemblies for loose and damaged fasteners and for cracks. AD 2009-24-13 also requires you to replace loose or damaged fasteners and replace cracked thrust attenuator paddles found during any inspection. Since we issued AD 2009-24-13, Cessna has developed new design thrust attenuator paddles and universal head rivets as terminating action for the repetitive inspections. Consequently, this proposed AD would retain the requirements of AD 2009-24-13 until replacement of both thrust attenuator paddles and the eight countersunk fasteners with new design thrust attenuator paddles and universal head rivets. We are proposing this AD to detect and correct loose and damaged fasteners and cracks in the thrust attenuator paddles, which could result in in-flight departure of the thrust attenuator paddles. This failure could lead to rudder and elevator damage and result in loss of control.

DATES:

We must receive comments on this proposed AD by May 14, 2010.

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, KS 67277; telephone: [phone]; fax: [phone]; Internet: http://www.cessna.com.

FOR FURTHER INFORMATION CONTACT:

TN Baktha, Aerospace Engineer, ACE-118W, Wichita Aircraft Certification Office (ACO), 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone: [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-2010-0327; Directorate Identifier 2010-CE-012-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

Reports of fatigue cracks found in thrust attenuator paddles on Cessna Model 525A airplanes caused us to issue AD 2009-24-13, Amendment 39-16105 (74 FR 62479, November 30, 2009). AD 2009-24-13 currently requires the following on Cessna Model 525A airplanes:

• Inspect repetitively the thrust attenuator paddle assemblies for loose and damaged fasteners and for cracks; and
• replace loose or damaged fasteners and replace cracked thrust attenuator paddles found during any inspection.

Four incidents of thrust attenuator paddles departing from airplanes have been reported. In two cases, the thrust attenuator paddles hit the rudder and caused structural damage to the rudder.

The thrust attenuator paddles are attached to the aft fuselage. The attachment fasteners fatigue and break.

It is also possible that a failed thrust attenuator paddle could depart the airplane and hit and damage the elevator.

We considered AD 2009-24-13 an interim action while Cessna developed a design improvement to change the attachment fasteners from the currently used counter sunk rivets to universal head rivets. Since we issued AD 2009-24-13, Cessna has developed new design thrust attenuator paddles and universal head rivets to replace the old design thrust attenuator paddle assemblies and the counter sunk fasteners.

This condition, if not corrected, could result in in-flight departure of the thrust attenuator paddles. This failure could lead to rudder and elevator damage and result in loss of control.

Relevant Service Information

We have reviewed:

• Cessna Citation Alert Service Letter ASL525A-78-01, Revision 1, dated October 27, 2009;
• Cessna Citation Service Bulletin SB525A-78-02, dated November 13, 2009, and
• Cessna Citation Service Bulletin SB525A-78-02, Revision 1, dated February 5, 2010.

Cessna Citation Alert Service Letter ASL525A-78-01 describes procedures for inspecting and modifying the thrust attenuator paddle assemblies.

Cessna Citation Service Bulletin SB525A-78-02 describes procedures for replacing the thrust attenuator paddles and attachment hardware.

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 2009-24-13 with a new AD that would retain the requirements of AD 2009-24-13 until you replace both thrust attenuator paddles and the eight countersunk fasteners with new design thrust attenuator paddles and universal head rivets. 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 136 airplanes in the U.S. registry.

We estimate the following costs to do the proposed inspection (retained from AD 2009-24-13):

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
1 work-hour × $85 per hour = $85	Not Applicable	$85	$11,560

We estimate the following costs to do any necessary installation (retained from AD 2009-24-13) of missing/damaged fasteners 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 for two fasteners	Total cost per airplane
2 work-hours × $85 per hour = $170	$99.90	$269.90

We estimate the following costs to do any necessary replacement (retained from AD 2009-24-13) of a cracked thrust attenuator paddle 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 (per paddle)	Total cost per airplane
3 work-hours × $85 per hour = $255	$1,200	$1,455

We estimate the following costs to do the proposed replacement of both thrust attenuator paddles and the eight countersunk fasteners with new design thrust attenuator paddles and universal head rivets:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
5 work-hours × $85 per hour = $425	$3,464	$3,889	$528,904

As determined by the manufacturer, eligible airplanes may qualify for warranty coverage of parts and labor.

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
• Incorporation by reference
• 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) 2009-24-13, Amendment 39-16105 (74 FR 62479, November 30, 2009), and adding the following new AD:

Cessna Aircraft Company: Docket No. FAA-2010-0327; Directorate Identifier 2010-CE-012-AD.

Comments Due Date

(a) We must receive comments on this airworthiness directive (AD) action by May 14, 2010.

Affected ADs

(b) This AD supersedes AD 2009-24-13, Amendment 39-16105.

Applicability

(c) This AD applies to Model 525A airplanes, serial numbers 0001 through 0244, that are certificated in any category.

Subject

(d) Air Transport Association of America (ATA) Code 72: Engine.

Unsafe Condition

(e) This AD results from reports of fatigue cracks found in thrust attenuator paddles on Cessna Model 525A airplanes. We are issuing this AD to detect and correct loose and damaged fasteners and cracks in the thrust attenuator paddles, which could result in in-flight departure of the thrust attenuator paddles. This failure could lead to rudder and elevator damage and result in loss of control.

Compliance

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

Actions	Compliance	Procedures
(1) Visually inspect the left and right thrust attenuator paddle assemblies to determine if there are any missing, loose, or damaged fasteners and to determine if there are any cracks in the paddle	Within the next 60 days after December 15, 2009 (the effective date of AD 2009-24-13) or within the next 30 hours time-in-service (TIS) after December 15, 2009 (the effective date of AD 2009-24-13), whichever occurs first. Repetitively inspect thereafter at intervals not to exceed 150 hours TIS	Follow Cessna Citation Alert Service Letter ASL525A-78-01, Revision 1, dated October 27, 2009.
(2) If you do not find any cracks in the thrust attenuator paddles during any inspection required in paragraph (f)(1) of this AD, install any missing fasteners, and replace any loose or damaged fasteners	Before further flight after the inspection required in paragraph (f)(1) of this AD. Continue with the repetitive inspections specified in paragraph (f)(1) of this AD	Follow Cessna Citation Alert Service Letter ASL525A-78-01, Revision 1, dated October 27, 2009.
(3) If cracks are found during any inspection required in paragraph (f)(1) of this AD, do a surface eddy current inspection of the thrust attenuator paddles and the fastener hole(s) to determine the length of the cracks(s)	Before further flight after the inspection required in paragraph (f)(1) of this AD in which cracks are found	Follow Cessna Citation Alert Service Letter ASL525A-78-01, Revision 1, dated October 27, 2009.
(4) If the cracks identified in paragraph (f)(3) of this AD meet or exceed the limits specified in paragraph 3 of Cessna Citation Alert Service Letter ASL525A-78-01, Revision 1, dated October 27, 2009, replace the thrust attenuator paddle and attachment hardware, as applicable	(i) If the conditions of paragraph 3.A.(1) of Cessna Citation Alert Service Letter ASL525A-78-01, Revision 1, dated October 27, 2009, are met, replace before further flight after the inspection required in paragraph (f)(3) of this AD. After the replacement, continue with the repetitive inspections specified in paragraph (f)(1) of this AD	Follow Cessna Citation Alert Service Letter ASL525A-78-01, Revision 1, dated October 27, 2009.
	(ii) If the conditions of paragraph 3.A.(2) of Cessna Citation Alert Service Letter ASL525A-78-01, Revision 1, dated October 27, 2009, are met, replace within the next 150 hours TIS after the inspection required in paragraph (f)(3) of this AD. After the replacement, continue with the repetitive inspections specified in paragraph (f)(1) of this AD
(5) Replace both thrust attenuator paddles	Within the next 300 hours TIS after the effective date of this AD or within 1 year after the effective date of this AD, whichever occurs first	Follow Cessna Citation Service Bulletin SB525A-78-02, Revision 1, dated February 5, 2010.

(g) The replacement required in paragraph (f)(5) of this AD terminates the repetitive inspection requirement of this AD. This replacement may be done at anytime, but must be done no later than 300 hours TIS or within 1 one after the effective date of this AD, whichever occurs first.

(h) If, before the effective date of this AD, you have done all the actions in the original issue of Cessna Citation Service Bulletin SB525A-78-02, dated November 13, 2009, then no further action is required by this AD. This is considered “unless already done” credit for this AD action.

Alternative Methods of Compliance (AMOCs)

(i) 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: TN Baktha, Aerospace Engineer, ACE-118W, Wichita Aircraft Certification Office (ACO), 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone: [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.

(j) AMOCs approved for AD 2009-24-13 are approved for this AD.

Related Information

(k) To get copies of the service information referenced in this AD, contact Cessna Aircraft Company, Product Support, P.O. Box 7706, Wichita, KS 67277; telephone: [phone]; fax: [phone]; Internet: http://www.cessna.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.

Issued in Kansas City, Missouri, on March 23, 2010.

Steven W. Thompson,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.