AD 97-12-06

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 97-12-06, which was sent previously to known U.S. owners and operators of certain Cessna Aircraft Company (Cessna) Model 172R airplanes. This AD requires checking the clearance between both the gascolator and cowling area and the tailpipe and cowling area, and modifying these areas immediately if any evidence of rubbing at either location is found or modifying the gascolator to cowling area within a certain time period if no evidence of rubbing at either location is found. This AD results from an occurrence of fuel loss on a Cessna Model 172R airplane, which was severe enough to force an emergency landing. Investigation of the occurrence reveals that the cowling knocked the gascolator drain valve off the gascolator. The actions specified by this AD are intended to prevent the cowling from rubbing against the gascolator drain valve or the tailpipe, which could result in fuelloss and engine stoppage.

Final rule; request for comments

97-12-06 CESSNA AIRCRAFT COMPANY: Amendment 39-10070; Docket No. 97-CE-35- AD. \n\tApplicability: Model 172R airplanes, serial numbers 17280001 through 17280081, certificated in any category. \n\n\tNOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. \n\n\tCompliance: Required as indicated in the body of this AD, unless already accomplished, except to those operators receiving this action by priority letter issued June 6, 1997, which made these actions effective immediately upon receipt. \n\n\tTo prevent the cowling from rubbing against the gascolator drain valve or the tailpipe, which could result in fuel loss and engine stoppage, accomplish the following: \n\n\t(a)\tPrior to further flight after the effective date of this AD, check the clearance between both the gascolator and cowling area and the tailpipe and cowling area for evidence of rubbing. \n\n\t\t(1)\tIf any evidence of rubbing is found, prior to further flight, modify both the gascolator and cowling area and tailpipe and cowling area in accordance with Cessna Service Bulletin SB97-28-01, dated June 6, 1997. \n\n\t\t(2)\tIf no evidence of rubbing is found, repeat the check in paragraph (a) before each flight, and within the next 10 hours time-in-service (TIS) after the effective date of this AD, modify the gascolator and cowling area in accordance with Figure 1 of this AD. \n\n\t(b)\tModifying both the gascolator and cowling area and tailpipe and cowling area in accordance with Cessna Service Bulletin SB97-28-01, dated June 6, 1997, satisfies all the requirements of this AD, and may be accomplished in place of the check required by paragraph (a) of this AD. \n\n\t(c)\tThe check required by paragraph (a) of this AD may be performed by the owner/operator holding at least a private pilot certificate as authorized by section 43.7 of the Federal Aviation Regulations (14 CFR 43.7), and must be entered into the aircraft records showing compliance with this AD in accordance with section 43.11 of the Federal Aviation Regulations (14 CFR 43.11). \n\n\t(d)\tSpecial flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location to accomplish the modification requirements of this AD provided no evidence of rubbing is found during thecheck required by paragraph (a) of this AD. \n\n\t\t(1)\tIf evidence of rubbing is found in either the gascolator to cowling area or the tailpipe to cowling area during the check required by paragraph (a) of this AD, then no special flight permits will be granted. \n\n\t\t(2)\tPrior to any flight granted through a special flight permit, the check required by paragraph (a) of this AD must be accomplished again to assure that no evidence of rubbing exists in either the gascolator to cowling area or the tailpipe to cowling area. If evidence of rubbing is found in either the gascolator to cowling area or the tailpipe to cowling area, then the special flight permit is not valid. \n\n\t(e)\tAn alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Wichita Aircraft Certification Office (ACO), 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Wichita ACO. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita ACO. \n\n\t(f)\tThe modifications required by this AD (if evidence of rubbing is found) shall be done in accordance with Cessna Service Bulletin SB97-28-01, dated June 6, 1997. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from the Cessna Aircraft Company, Product Support, P.O. Box 7706, Wichita, Kansas 67277. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(g)\tThis amendment (39-10070) becomes effective on July 15, 1997, to all persons except those persons to whom it was made immediately effective by priority letter AD 97-12-06, issued June 6, 1997, which contained the requirements of this amendment. \n\nFigure 1

Discussion\n\tOn June 6, 1997, the FAA issued priority letter AD 97-12-06, which applies to certain Cessna Model 172R airplanes. That AD resulted from an occurrence of fuel loss on one of these airplanes, which was severe enough to force an emergency landing. Investigation of the occurrence revealed that the cowling knocked the gascolator drain valve off the gascolator.\n\n\tFurther examination of the design of the Model 172R airplanes shows that this condition exists when the tailpipe vibrates, during some starting conditions, into the cowling. The cowling then rubs against the gascolator drain valve, knocking the gascolator drain valve off the gascolator, and causing fuel to drain from the airplane at an extremely high flow rate. This results in engine stoppage with consequent forced landing or crash landing.\n\nDiscussion of the Applicable Service Information\n\tThe FAA has reviewed and approved Cessna Service Bulletin SB97-28-01, dated June 6, 1997.This service bulletin includes procedures for modifying the gascolator to cowling clearance and tailpipe to cowling clearance.\n\nThe FAA's Determination and Explanation of the AD\n\tSince an unsafe condition has been identified that is likely to exist or develop in other Cessna Model 172R airplanes of the same type design, the FAA issued priority letter AD 97-12-06 to prevent the cowling from rubbing against the gascolator drain valve or the tailpipe, which could result in fuel loss and engine stoppage. The AD requires checking the clearance between both the gascolator and cowling area and the tailpipe and cowling area, and modifying these areas immediately if any evidence of rubbing at either location is found or modifying the gascolator to cowling area within 10 hours time-in-service (TIS) if no evidence of rubbing at either location is found. Accomplishment of the modifications is in accordance with Cessna Service Bulletin SB97-28-01 if rubbing is evident, or in accordance with Figure 1 of this AD if no rubbing is evident.\n\nDetermination of the Effective Date of the AD\n\tSince it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual letters issued on June 6, 1997, to known U.S. operators of certain Cessna Models 172R airplanes. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective as to all persons.\n\nComments Invited\n\tAlthough this action is in the form of a final rule that involves requirements affecting immediate flight safety and, thus, was not preceded by notice and opportunity to comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.\n\n\tComments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.\n\n\tCommenters wishing the FAA to acknowledgereceipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 97-CE-35-AD." The postcard will be date stamped and returned to the commenter.\n\nRegulatory Impact\n\tThe regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.\n\n\tThe FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES".\n\nList of Subjects in 14 CFR Part 39\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.\n\nADOPTION OF THE AMENDMENT\n\tAccordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation \nAdministration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:\n\nPART 39 - AIRWORTHINESS DIRECTIVES\n\t1. The authority citation for part 39 continues to read as follows:\n\tAuthority: 49 USC 106(g), 40113, 44701.\n\n§ 39.13 (Amended)\n\t2. Section 39.13 is amended by adding anew airworthiness directive (AD) to read as follows: