Airworthiness Directives: Twin Commander Aircraft Corporation Models 690, 690A, and 690B Airplanes
Federal Register: August 28, 2009 (Volume 74, Number 166)
Proposed Rules
Page 44308-44311
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
DOCID:fr28au09-17
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration 14 CFR Part 39
Docket No. FAA-2009-0778; Directorate Identifier 2009-CE-040-AD
RIN 2120-AA64
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: We propose to adopt a new airworthiness directive (AD) for certain Twin Commander Aircraft Corporation Models 690, 690A, and 690B airplanes. This proposed AD would require you to inspect between the surface of the left-hand (LH) and right-hand (RH) upper wing skins and the engine mount beam support straps for any signs of corrosion, replace the upper steel straps with parts of improved design, and modify both wings. This proposed AD results from reports that corrosion was found between the mating surfaces of the wing upper skin surface and the engine mount beam support straps. We are proposing this AD to detect and correct corrosion on the engine mount beam support straps and the upper wing skins, which could result in failure of the engine mount beam support straps. This failure could lead to loss of the engine and possible loss of control of the airplane.
DATES: We must receive comments on this proposed AD by October 13, 2009.
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: (202) 493-2251.
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
Twin Commander Aircraft, LLC, 19010 59th Drive, NE., Arlington, WA 98223, telephone: (360) 435-9797; fax: (360) 435-1112; Internet: www.twincommander.com.
FOR FURTHER INFORMATION CONTACT: Vince Massey, Aerospace Engineer, FAA,
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98057-3356; telephone: (425) 917-6475; fax: (425) 917-6590; e-mail: vince.massey@faa.gov.
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- 2009-0778; Directorate Identifier 2009-CE-040-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://
Page 44309
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 a report that corrosion was found between the mating surfaces of the wing upper skin surface and the engine mount beam support straps. These straps carry engine loads from the support beams into the upper wing skins and wing internal support structure.
Severe corrosion of the straps can lead to inability to carry engine loads.
This condition, if not corrected, could result in failure of the engine mount beam support straps. This failure could lead to loss of the engine and possible loss of control of the airplane.
Relevant Service Information
We have reviewed Twin Commander Aircraft LLC Alert Service Bulletin
No. 237, dated May 13, 2005. The service information describes procedures for inspecting the surface of the LH and RH upper wing skins and the engine mount beam support straps for any signs of corrosion, replacing the upper steel straps with parts of improved design, and modifying both wings.
We have reviewed Twin Commander Aircraft Corporation Custom Kit No. 150, dated July 8, 1994. The service information describes procedures for installing inspection access holes in the LH and RH upper wing skins.
We have reviewed Gulfstream American Corporation Service Bulletin
No. 182, dated March 2, 1981. The service information describes procedures for installing additional wing fasteners on the LH and RH wing.
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 inspect between the surface of the LH and RH upper wing skins and the engine mount beam support straps for any signs of corrosion, replace the upper steel straps with parts of improved design, and modify both wings.
Costs of Compliance
We estimate that this proposed AD would affect 275 airplanes in the
U.S. registry.
We estimate the following costs to do the proposed inspection:
Total cost
Labor cost
Parts cost
per
Total cost on airplane U.S. operators
80 work-hours x $80 per hour = $6,400.......... Not applicable....................
$6,400
$1,760,000
We estimate the following costs to do any necessary repairs/ 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 repair/replacement:
Short Modification--Option A*
Total cost per
Labor cost
Parts cost
airplane per side
250 work-hours x $80 per hour =
$9,170 per kit per
$29,170
$20,000 per side.
side.
Middle Modification--Option B*
Total cost per
Labor cost
Parts cost
airplane per side
280 work-hours x $80 per hour =
$9,170 per kit per
$31,570
$22,400 per side.
side.
Long Modification--Option C*
Total cost per
Labor cost
Parts cost
airplane per side
320 work-hours x $80 per hour =
$9,170 per kit per
$34,770
$25,600 per side.
side.
Note: *Depending on airplane configuration, airplanes with rectangular plates would need the Plate and Hardware Kit (SB237-4) at $2,090 per side. Labor to install this kit is included in Options
A, B, and C.
Strap Only Replacement--Option D
Total cost per
Labor cost
Parts cost
airplane per side
75 work-hours x $80 per hour =
$6,190 per strap per
$12,190
$6,000 per side.
side.
Page 44310
We estimate the following costs to do the proposed installation of access holes:
Total cost
Labor cost
Parts cost
per
Total cost on airplane U.S. operators
30 work-hours x $80 per hour =
$1,293
$3,693
$1,015,575
$2,400.......................
We estimate the following costs to do the proposed wing fastener modification:
Total cost
Labor cost
Parts cost
per
Total cost on airplane U.S. operators
8.5 work-hours x $80 per hour
$250
$930
$255,750
= $680.......................
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 (800) 647-5527) 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.
Sec. 39.13 [Amended] 2. The FAA amends Sec. 39.13 by adding the following new AD:
Twin Commander Aircraft Corporation: Docket No. FAA-2009-0778;
Directorate Identifier 2009-CE-040-AD.
Comments Due Date
(a) We must receive comments on this airworthiness directive
(AD) action by October 13, 2009.
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 Nos. (S/Ns)
690....................................... All S/Ns. 690A...................................... All S/N except 11195 and 11279. 690B...................................... All S/Ns except 11361, 11383, 11527, and 11536.
Unsafe Condition
(d) This AD results from reports that corrosion was found between the mating surfaces of the wing upper skin surface and the engine mount beam support straps. We are issuing this AD to detect and correct corrosion on the engine mount beam support straps and upper wing skins, which could result in failure of the engine mount beam support straps. This failure could lead to loss of the engine and possible loss of control of the airplane.
Compliance
(e) To address this problem, you must do the following, unless already done:
Page 44311
Actions
Compliance
Procedures
(1) Inspect between the
Within the next 150 Follow Twin surface of the left-hand
hours time-in-
Commander Aircraft
(LH) and right-hand (RH)
service after the
LLC Alert Service upper wing skins and the
effective date of
Bulletin No. 237, engine mount beam support
this AD or within
dated May 13, 2005, straps for any signs of
the next 12 months pages 1 through 14. corrosion and determine the after the effective extent of any corrosion
date of this AD, found.
whichever occurs first.
(2) Install modification
Before further
Follow the access holes in the LH and flight after the
Accomplishment
RH lower wing skins.
inspection required Instructions, steps in paragraph (e)(1) 1 through 4 and 6 of this AD.
through 9, of Twin
Commander Aircraft
Corporation Custom
Kit No. 150, dated
July 8, 1994, as specified in Twin
Commander Aircraft
LLC Alert Service
Bulletin No. 237, dated May 13, 2005.
(3) If corrosion damage is
Before further
Follow Twin found during the inspection flight after the
Commander Aircraft required in paragraph
inspection required LLC Alert Service
(e)(1) of this AD, perform in paragraph (e)(1) Bulletin No. 237, necessary modification.
of this AD.
dated May 13, 2005,
Part II, Options A,
B, or C, on pages 15 through 29, and 31.
(4) If corrosion damage is
Before further
Follow Twin not found during the
flight after the
Commander Aircraft inspection required in
inspection required LLC Alert Service paragraph (e)(1) of this
in paragraph (e)(1) Bulletin No. 237,
AD, do the upper steel
of this AD.
dated May 13, 2005, strap replacements.
Part II, Option D, on pages 30 and 31.
(5) Install additional wing Before further
Follow Gulfstream fasteners on the LH and RH flight after the
American wing.
inspection required Corporation Service in paragraph (e)(1) Bulletin No. 182, of the AD.
dated March 2, 1981.
Note: Although not required by this AD, we highly recommend compliance with Twin Commander Aircraft Corporation Service Bulletin
No. 217, Revision No. 1, dated May 26, 1993, Engine Nacelle Firewall
Reinforcement; and Twin Commander Aircraft LLC Alert Service
Bulletin No. 239, dated February 13, 2006, Outboard Flap--Inboard
Hinge Inspection & Reinforcement.
Alternative Methods of Compliance (AMOCs)
(f) The Manager, Seattle 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: Vince Massey, Aerospace Engineer, FAA, Seattle ACO, 1601 Lind
Avenue, SW., Renton, Washington 98057-3356; telephone: (425) 917- 6475; fax: (425) 917-6590; e-mail: vince.massey@faa.gov. 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 Twin Commander Aircraft, LLC, 19010 59th Drive, NE.,
Arlington, WA 98223, telephone: (360) 435-9797; fax: (360) 435-1112;
Internet: www.twincommander.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 August 21, 2009.
Kim Smith,
Manager, Small Airplane Directorate, Aircraft Certification Service.
FR Doc. E9-20789 Filed 8-27-09; 8:45 am
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