AD 2009-08-05

We are adopting a new airworthiness directive (AD) for certain Liberty Aerospace Incorporated Model XL-2 airplanes. This AD requires you to repetitively inspect the exhaust muffler for cracks and to replace the exhaust muffler when cracks are found. This AD is the result of reports that cracks have been found in the exhaust muffler during maintenance and service inspections. We are issuing this AD to detect and correct cracks in the exhaust muffler, which could result in carbon monoxide entering the cabin through the heating system. Carbon monoxide entering into the airplane cabin could lead to incapacitation of the pilot.

Final rule; request for comments.

2009-08-05 Liberty Aerospace Incorporated: Amendment 39-15878; Docket No. FAA-2009-0329; Directorate Identifier 2009-CE-020-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective on April 20, 2009. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Model XL-2 airplanes, serial numbers 0007, 0009, and subsequent, that are certificated in any category. \n\nUnsafe Condition \n\n\t(d) This AD is the result of reports that eight cracks have been found in the exhaust muffler during maintenance and service inspections. We are issuing this AD to detect and correct cracks in the exhaust muffler, which could result in carbon monoxide entering the cabin heating system. This condition could lead to incapacitation of the pilot. \n\nCompliance \n\n\t(e) To address this problem, you must do the following, unless already done: \n\n\nActions \nCompliance \nProcedures \n(1) Inspect the following: \n(i) The exhaust muffler for cracks. There are two different exhaust systemsavailable for the affected airplanes. They are: \n(A) Standard exhaust system, part number (P/N) DEL200201-002 that incorporates muffler P/N DEL200201- 101; and \n(B) Reduced sound exhaust system, P/N DEL200201-003 that incorporates muffler P/N 200201-104. \n(ii) The tail pipe and the tail pipe opening in the lower cowl for a 0.5-inch minimum clearance. \n(iii) Inspect the propeller for proper propeller clocking position. \nInitially inspect within the next 10 hours time-in-service (TIS) after April 20, 2009 (the effective date of this AD) or at the next annual inspection, whichever occurs first. Repetitively inspect the exhaust muffler thereafter as specified in paragraph (e)(5) of this AD. \nFollow Liberty Aerospace, Inc. Service Document Critical Service Bulletin (CSB) CSB-09-001, Revision Level B, Revised on March 18, 2009. \n(2) As a result of the inspections required in paragraphs (e)(1)(ii) and (e)(1)(iii) of this AD: (i) If the clearance between the tail pipe and the tail pipeopening is less than the required 0.5-inch minimum, trim the lower cowl as needed to achieve the minimum clearance. (ii) If there is a discrepancy in the propeller clocking position, remove and reinstall the propeller at the correct position. \nBefore further flight after the inspection required in paragraph (e)(1) of this AD. \nAs specified in Liberty Aerospace, Inc. Service Document Critical Service Bulletin (CSB) CSB-09- 001, Revision Level B, Revised on March 18, 2009. \n(3) As a result of the initial inspection required in paragraph (e)(1)(i) of this AD or any repetitive inspection required in paragraph (e)(5) of this AD, if a crack is found, replace the exhaust muffler. (i) The manufacturer will provide the replacement exhaust system. (ii) A reduced sound exhaust system may be replaced with a standard exhaust system. (iii) Installing a reduced sound exhaust system as a replacement part also requires installing a bypass SCAT tube and a "Do Not Use" placard on or near the heater knob. \nBefore further flight after the initial inspection required in paragraph (e)(1) of this AD and before further flight after any repetitive inspection required in paragraph (e)(5) of this AD. \nFollow Liberty Aerospace, Inc. Service Document Critical Service Bulletin (CSB) CSB-09-001, Revision Level B, Revised on March 18, 2009. \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n(4) If the airplane is equipped with a reduced sound exhaust system and no cracks are found during the initial inspection required in paragraph (e)(1) of this AD, install a bypass SCAT tube and a "Do Not Use" placard on or near the heater knob. \nWithin the next 10 hours TIS after April 20, 2009 (the effective date of this AD. \nFollow Liberty Aerospace, Inc. Service Document Critical Service Bulletin (CSB) \nCSB-09-001, Revision Level B, Revised on March \n18, 2009. \n(5) If no cracks are found in the exhaust muffler during the initial inspection required in paragraph (e)(1) of this AD or if the exhaust muffler was replaced as required in paragraph (e)(3) of this AD, repetitively inspect thereafter at the intervals specified in paragraphs (e)(5)(i), (e)(5)(ii), and (e)(5)(iii) of this AD. \n(i) For airplanes equipped with a standard exhaust system and the optional bypass SCAT tube has not been installed, repetitively inspect thereafter every 25 hours TIS or every 12 months, whichever occurs first. \n(ii) For airplanes equipped with a standard exhaust system and the optional bypass SCAT tube has been installed, repetitively inspect thereafter every 50 hours TIS or every 12 months, whichever occurs first. \n(iii) For airplanes equipped with a reduced sound exhaust system and the required bypass SCAT tube has been installed, repetitively inspect thereafter every 50 hours TIS or every 12 months, whichever occurs first. \nFollow Liberty Aerospace, Inc. Service Document Critical Service Bulletin (CSB) CSB-09-001, Revision Level B, Revised on March 18, 2009. \n(6) Report the results of the following inspections required in this AD to the FAA. \n(i) Initial inspection required in paragraph (e)(1) of this AD. \n(ii) Repetitive inspections required in paragraph (e)(5) of this AD only if cracks are found. (iii) The Office of Management and Budget (OMB) approved the information collection requirements contained in this regulation under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and assigned OMB Control Number 2120-0056. \nWithin 10 days after each inspection required by this AD. \nUse the form (Figure 1 of this AD) and submit it to FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Blvd., Suite 450, Atlanta, Georgia 30349. \n\n\n\n\n\nSpecial Flight Permit \n\n\t(f) Under 14 CFR part 39.23, we are limiting the special flight permits for this AD by the following conditions: \n\t(1) The cabin heat turned off; and \n\t(2) The fresh air vents are open. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(g) The Manager, AtlantaAircraft 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: Corey Spiegel, Aerospace Engineer, Atlanta ACO, One Crown Center, 1895 Phoenix Blvd., Suite 450, Atlanta, Georgia 30349. 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. \n\nMaterial Incorporated by Reference \n\n\t(h) You must use Liberty Aerospace, Inc. Service Document Critical Service Bulletin (CSB) CSB-09-001, Revision Level B, Revised on March 18, 2009, to do the actions required by this AD, unless the AD specifies otherwise. \n\t(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. \n\t(2) For service information identified in this AD, contact Liberty Aerospace, 100 Aerospace Drive, Melbourne, Florida 32901; telephone: (321) 752-0332 or (800) 759-5953; fax: (321) 752-0377; Internet: http://www.libertyaircraft.com. \n\t(3) You may review copies of the service information incorporated by reference for this AD at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Kansas City, Missouri 64106. For information on the availability of this material at the Central Region, call (816) 329-3768. \n\t(4) You may also review copies of the service information incorporated by reference for this AD at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http:// www.archives.gov/federal_register/code_of_federal_regulations/ ibr_locations.html.

Discussion \n\n\tWe received reports of cracks found in the exhaust mufflers of Liberty Aerospace Incorporated (Liberty Aerospace) Model XL-2 airplanes. One crack was found during maintenance, which prompted Liberty Aerospace to publish service information requesting the exhaust mufflers be inspected for cracks on all Model XL-2 airplanes. Seven additional cracks have been found during these service inspections. \n\tInvestigation is ongoing to determine what is causing the exhaust mufflers to crack. Excessive vibration caused by improper propeller clocking position may be a contributing factor. \n\tThis condition, if not corrected, could result in carbon monoxide entering the cabin through the heating system and cause incapacitation of the pilot. \n\nRelevant Service Information \n\n\tWe reviewed Liberty Aerospace, Inc. Service Document Critical Service Bulletin (CSB) CSB-09-001, Revision Level B, Revised on March 18, 2009. The service information describes procedures for inspecting the exhaust muffler for cracks and replacing the exhaust muffler when cracks are found. \n\nFAA's Determination and Requirements of This AD \n\n\tWe are issuing this AD because we evaluated all the information and determined the unsafe condition described previously is likely to exist or develop on other products of the same type design. This AD requires repetitively inspecting the exhaust muffler for cracks and replacing the exhaust muffler when cracks are found. This AD also requires inspecting the propeller for proper clocking position and correcting any discrepancies found. \n\tLiberty Aerospace is reviewing the information related to the occurrences referenced in this AD and may develop a modification that, when incorporated, would eliminate the need for the repetitive inspections required by this AD. The FAA will review any modification that is developed, determine whether it would eliminate the need for the requirements of this action, and then determine whether additional AD action is necessary. \n\nFAA's Determination of the Effective Date \n\n\tAn unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because cracks in the exhaust muffler could result in carbon monoxide entering the cabin through the heating system. Carbon monoxide entering into the airplane cabin could lead to incapacitation of the pilot. Therefore, we determined that notice and opportunity for public comment before issuing this AD are impracticable and that good cause exists for making this amendment effective in fewer than 30 days. \n\nComments Invited \n\n\tThis AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and an opportunity for public comment. We invite you to send any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number ''FAA-2009-0329; Directorate Identifier 2009-CE-020-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the AD in light of those comments. \n\tWe 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 AD. \n\nAuthority for This Rulemaking \n\n\tTitle 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. \n\tWe 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. \n\nRegulatory Findings \n\n\tWe determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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. \n\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a ''significant regulatory action'' under Executive Order 12866; \n\t(2) Is not a ''significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\t(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. \n\tWe prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. \n\nExamining the AD Docket \n\n\tYou may examine the AD docket that contains the 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. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD):