[Federal Register Volume 63, Number 50 (Monday, March 16, 1998)] [Proposed Rules] [Pages 12706-12708] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-6585] ======================================================================= ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 97-CE-129-AD] RIN 2120-AA64 Airworthiness Directives; Stemme GmbH & Co. KG Models S10 and S10-V Sailplanes AGENCY: Federal Aviation Administration, DOT. ACTION: Notice of proposed rulemaking (NPRM). ----------------------------------------------------------------------- SUMMARY: This document proposes to adopt a new airworthiness directive (AD) that would apply to certain Stemme GmbH & Co. KG (Stemme) Models S10 and S10-V sailplanes. The proposed action would require replacing the fuel filter, inserting a revision to the Limitations Section of the airplane flight manual, and inspecting the engine valve shafts for brownish-black sticky residue. If a residue is found on the valve shafts, the proposed action would require cleaning the engine. The proposed AD is the [[Page 12707]] result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. The actions specified by the proposed AD are intended to prevent engine valve malfunction, which, if not corrected, could cause engine failure during flight and loss of control of the sailplane. DATES: Comments must be received on or before April 17, 1998. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 97-CE-129-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. Comments may be inspected at this location between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted. Service information that applies to the proposed AD may be obtained from Stemme GmbH & Co. KG, Gustav-Meyer-Allee 25, D-13355 Berlin, Federal Republic of Germany. This information also may be examined at the Rules Docket at the address above. FOR FURTHER INFORMATION CONTACT: Mr. Mike Kiesov, Aerospace Engineer, Small Airplane Directorate, Aircraft Certification Service, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106; telephone (816) 426- 6934; facsimile (816) 426-2169. SUPPLEMENTARY INFORMATION: Comments Invited Interested persons are invited to participate in the making of the proposed 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, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket No. 97-CE-129-AD.'' The postcard will be date stamped and returned to the commenter. Availability of NPRMs Any person may obtain a copy of this NPRM by submitting a request to the FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 97-CE-129-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. Discussion The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, recently notified the FAA that an unsafe condition may exist on certain Stemme Models S10 and S10-V sailplanes. The LBA reports engine failure on two of the affected sailplanes. The engine failures occurred on sailplanes that were found to have a brown sticky substance on the engine. This substance is brownish-black in color and ranges from a lacquer-like hardness to gum-like sticky in composition. The substance may be residue and build-up formed by foreign materials dissolved in the fuel. The composition of the residue is causing the intake valves to stick in the valve guides. Sticky deposits were also found in parts of the induction system on the inside walls of the intake manifolds, as well as on the throttle shaft. This condition, if not corrected, could result in engine failure during flight and loss of control of the sailplane. Relevant Service Information Stemme has issued Service Bulletin (SB) No. A31-10-021, dated June 28, 1995, which specifies inserting a revision to the Limitations Section in the airplane flight manual (AFM) restricting the type and grade of fuel to use in the sailplane engine; and, specifies procedures for replacing the fuel filter if contaminated, along with inspecting the engine for the sticky brown residue. Limbach Flugmotoren Technical Bulletin No. 47, dated June 28, 1995, specifies procedures for inspecting certain engine components for contamination, and cleaning the engine. These procedures are a follow- on to those found in Stemme SB No. A31-10-021, when a sticky brown residue is found in the engine. The LBA classified these service bulletins as mandatory and issued German AD 95-273, dated July 11, 1995, in order to assure the continued airworthiness of these sailplanes in Germany. The FAA's Determination This sailplane model is manufactured in Germany and is type certificated for operation in the United States under the provisions of Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the LBA has kept the FAA informed of the situation described above. The FAA has examined the findings of the LBA, reviewed all available information, including the service information referenced above, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States. Explanation of the Provisions of the Proposed AD Since an unsafe condition has been identified that is likely to exist or develop in other Stemme Models S10 and S10-V sailplanes of the same type design registered in the United States, the proposed AD would require replacing the fuel filter if contaminated, inserting a revision to the Limitations Section of the airplane flight manual (AFM), and inspecting the engine valve shafts for brownish-black sticky residue. If a residue is found on the valve shafts, the proposed action would require cleaning the engine. Accomplishment of the proposed insertion, inspection, and cleaning would be in accordance with Stemme Service Bulletin No. A31-10-021, dated June 28, 1995, and Limbach Flugmotoren Technical Bulletin No. 47, dated June 28, 1995. Cost Impact The FAA estimates that 9 sailplanes in the U.S. registry would be affected by the proposed AD, that it would take approximately 5 workhours per sailplane to accomplish the proposed action, and that the average labor rate is approximately $60 an hour. Parts cost approximately $30 per sailplane. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $2,970, or $330 per sailplane. Proposed Compliance Time The FAA is proposing a calendar compliance time instead of hours time-in-service (TIS) because the average monthly usage of the affected sailplanes varies throughout the fleet. For example, one owner may operate the sailplane 25 hours TIS in one week, while another operator may operate the sailplane 25 [[Page 12708]] hours TIS in one year. The sticky residue builds up on the engine regardless of sailplane use. In order to assure that all of the affected sailplanes are in compliance within a reasonable amount of time, the FAA is proposing a compliance time of 30 days after the effective date of this AD to insert the AFM Limitations Section revision, and 60 days after the effective date of this AD to replace the fuel filter and inspect the engine. Regulatory Impact The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this action (1) is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action has been placed in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Safety. The Proposed Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: Stemme GMBH & Co. KG: Docket No. 97-CE-129-AD. Applicability: Model S10 (serial numbers 10-12 through 10-60), and Model S10-V (serial numbers 14-002 through 14-022) and transformed Model S10-V (serial numbers 14-012M to 14-060M) sailplanes, certificated in any category. Note 1: This AD applies to each sailplane 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 sailplanes 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. Compliance: Required as indicated in the body of this AD, unless already accomplished. To prevent engine valve malfunction, which, if not corrected, could cause engine failure during flight and loss of control of the sailplane, accomplish the following: (a) Within the next 30 days after the effective date of this AD, insert a revision in the Limitations Section 2.4.2.1, Fuel, of the airplane flight manual (AFM) that states: ``Only authorized fuel is AVGAS 100LL'' in accordance with the Instructions section of Stemme Service Bulletin (SB) Document No. A31-10-021, dated June 28, 1995. (b) Incorporating the revision to the Limitations Section of the AFM, as 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 43.9 of the Federal Aviation Regulations (14 CFR 43.9). (c) Within the next 60 days after the effective date of this AD, accomplish paragraphs (c)(1), (c)(2), and (c)(3) of this AD; (1) Inspect the fine fuel filter for the accumulation of chopped cotton fibers, and replace the filter if it is contaminated, prior to further flight, in accordance with the Instructions section of Stemme SB Document No. A31-10-021, dated June 28, 1995; and, (2) Inspect the engine in accordance with LIMBACH Flugmotoren Technical Bulletin No. 47, dated June 28, 1995. (3) If a brownish-black sticky residue is found on the engine, prior to further flight, disassemble and clean the engine in accordance with LIMBACH Flugmotoren Technical Bulletin No. 47, dated June 28, 1995. (d) Special 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 sailplane to a location where the requirements of this AD can be accomplished. (e) An alternative method of compliance or adjustment of the compliance times that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Manager, Small Airplane Directorate. (f) Questions or technical information related to Stemme Service Bulletin No. A31-10-021, dated June 28, 1995, and LIMBACH Flugmotoren Technical Bulletin No. 47, dated June 28, 1995, should be directed to Stemme GmbH & Co. KG, Gustav-Meyer-Allee 25, D-13355 Berlin, Federal Republic of Germany. This service information may be examined at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. Note 3: The subject of this AD is addressed in German AD 95-273, dated July 11, 1995. Issued in Kansas City, Missouri, on March 9, 1998. Michael Gallagher, Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-6585 Filed 3-13-98; 8:45 am] BILLING CODE 4910-13-U