E6-3798. Airworthiness Directives; Twin Commander Aircraft Corporation Models 690, 690A, and 690B Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all Twin Commander Aircraft Corporation (Twin Commander) Models 690, 690A, and 690B airplanes. This proposed AD would require you to inspect, visually and using fluorescent dye penetrant, the support structures for the inboard and center aileron hinge fittings on both wings for cracks and replace any cracked support structure. This proposed AD would require you to reinforce the support structures for the inboard and center aileron hinge fittings on both wings. This proposed AD results from reports that cracks were found in the support structures for the inboard and center aileron hinge fittings on both wings. We are issuing this proposed AD to detect and correct cracks in the support structures for the inboard and center aileron hinge fittings on both wings, which could result in aileron failure. This failure could lead to reduced controllability or loss of control of the airplane.

DATES:

We must receive comments on this proposed AD by May 16, 2006.

ADDRESSES:

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

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Twin Commander Aircraft LLC, 19010 59th Drive, NE., Arlington, WA 98223, telephone: [phone]; facsimile: [phone], for the service information identified in this proposed AD.

You may examine the comments on this proposed AD in the AD docket on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT:

Vince Massey, Aerospace Engineer, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, WA 98055-4056; telephone: [phone]; facsimile: [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include the docket number, “FAA-2006-23785; Directorate Identifier 2006-CE-10-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed rulemaking. Using the search function of the DOT docket Web site, anyone can find and read the comments received into any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78) or you may visit http://dms.dot.gov.

Examining the Dockets

You may examine the docket that contains the proposal, any comments received and any final disposition on the Internet at http://dms.dot.gov,, or in person at the DOT Docket Offices between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone [phone]) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the Docket Management Facility receives them.

Discussion

The FAA has received reports that cracks were found in the support structures for the inboard and center aileron hinge fittings on both wings on Twin Commander Models 690, 690A, and 690B airplanes.

This condition, if not detected and corrected, could result in failure of the aileron. This failure could lead to reduced controllability or loss of control of the airplane.

Relevant Service Information

We have reviewed Twin Commander Aircraft LLC Alert Service Bulletin 236A and Alert Service Bulletin 238, both dated December 21, 2004.

The service information describes procedures for:

• Inspecting, visually and using fluorescent dye penetrant, the support structures for the inboard and center aileron hinge fittings on both wings for cracks;
• Replacing cracked support structures; and
• Reinforcing the support structures for the inboard and center aileron hinge fittings on both wings.

FAA's Determination and Requirements of This Proposed AD

We are proposing this AD to address an unsafe condition that we determined is likely to exist or develop on other products of this same type design. This proposed AD would require you to inspect, visually and using fluorescent dye penetrant, the support structures for the inboard and center aileron hinge fittings on both wings for cracks and replace any cracked support structure. This proposed AD would require you to reinforce the support structures for the inboard and center aileron hinge fittings on both wings. 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 affects 275 airplanes in the U.S. registry.

We estimate the following costs to do the proposed inspection of the support structures of the inboard aileron hinge fittings on both wings:

Labor cost	Parts cost	Total cost for each airplane	Total cost on U.S. operators
10 work hours × $80 an hour = $800	Not applicable	$800	$800 × 275 = $220,000.

We estimate the following costs to do the proposed inspection of the support structure of the center aileron hinge fittings on both wings:

Labor cost	Parts cost	Total cost for each airplane	Total cost on U.S. operators
12 work hours × $80 an hour = $960	Not applicable	$960	$960 × 275 = $264,000.

We estimate the following costs to do the proposed reinforcements to the support structures of the inboard aileron hinge fittings on both wings:

Labor cost	Parts cost	Total cost for each airplane	Total cost on U.S. operators
25 work hours × $80 an hour = $2,000	$1,526	$2,000 + $1,526 = $3,526	$3,526 × 275 = $969,650.

We estimate the following costs to do the proposed reinforcement of the support structure of the center aileron hinge fittings on both wings:

Labor cost	Parts cost	Total cost for each airplane	Total cost on U.S. operators
50 work hours × $80 an hour = $4,000	$551	$4,000 + $551 = $4,551	$4,551 × 275 = $1,251,525.

We estimate the following costs to do any proposed replacements of the support structures for the inboard aileron hinge fittings on both wings 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 for each airplane
62 work hours × $80 an hour = $4,960	$2,320	$4,960 + $2,320 = $7,280.

We estimate the following costs to do any proposed replacements of support structure for the center aileron hinge fittings on both wings 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 for each airplane
176 work hours × $80 an hour = $14,080	$3,330	$14,080 + $3,330 = $17,410.

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. See the ADDRESSES section for a location to examine the regulatory evaluation.

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:

Twin Commander Aircraft Corporation: Docket No. FAA-2006-23785; Directorate Identifier 2006-CE-10-AD.

Comment Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this proposed AD action by May 16, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD affects Models 690, 690A, and 690B airplanes, all serial numbers, that are certificated in any category.

Unsafe Condition

(d) This AD results from reports of cracks found in the support structures for the inboard and center aileron hinge fittings on both wings. The actions specified in this AD are intended to detect and correct cracks in the support structures for the inboard and center aileron hinge fittings on both wings, which could result in aileron failure. This failure could lead to reduced controllability or loss of control of the airplane.

Compliance

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

Actions	Compliance	Procedures
(1) Inspect, visually and using fluorescent dye penetrant, the support structures for the inboard and center aileron hinge fittings on both wings for cracks	Within the next 150 hours time-in-service (TIS) or 12 months after the effective date of this AD, whichever occurs first	Follow Twin Commander Aircraft LLC Alert Service Bulletin 236A and Alert Service Bulletin 238, both dated December 21, 2004, as applicable.
(2) If you do not find cracks during the inspection required in paragraph (e)(1) of this AD, reinforce the support structures for the inboard and center aileron hinge fittings on both wings that are crack free	Before further flight after the inspection required in paragraph (e)(1) of this AD. After the reinforcement is done, no further action is required	Follow Twin Commander Aircraft LLC Alert Service Bulletin 236A and Alert Service Bulletin 238, both dated December 21, 2004, as applicable.
(3) If you find cracks during the inspection required in paragraph (e)(1) of this AD, replace and reinforce the cracked support structure	Before further flight after the inspection required in paragraph (e)(1) of this AD. After doing the replacement and reinforcement, no further action is required	Follow Twin Commander Aircraft LLC Alert Service Bulletin 236A and Alert Service Bulletin 238, both dated December 21, 2004, as applicable.

Alternative Methods of Compliance (AMOCs)

(f) The Manager, Seattle Aircraft Certification Office (ACO), FAA, ATTN: Vince Massey, Aerospace Engineer, Seattle Aircraft Certification Office, 1601 Lind Avenue SW, Renton, WA 98055-4056; telephone: [phone]; fax: [phone], has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

Related Information

(g) To get copies of the documents referenced in this AD, contact Twin Commander Aircraft LLC, 19010 59th Drive NE, Arlington, WA 98223, telephone: [phone]; facsimile: [phone]. To view the AD docket, go to the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC, or on the Internet at http://dms.dot.gov. The docket number is Docket No. FAA-2006-23785; Directorate Identifier 2006-CE-10-AD.

Issued in Kansas City, Missouri, on March 10, 2006.

Kim Smith,

Manager, Small Airplane Directorate, Aircraft Certification Service.