# Marvel-Schebler Emergency Service Bulletin 18: Revision A - Rights: © Marvel-Schebler. Filed by the FAA in regulations.gov docket FAA-2011-0533; AD 2012-03-07 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Marvel-Schebler Emergency Service Bulletin 18](https://openairdocs.org/service-documents/marvel-schebler/sb-18.md) - Title as filed: U.S. DOT/FAA - Service Information - Pages: 4 - PDF: https://openairdocs.org/files/sha256/4d/b0/4db0ec6ed6a3773aaee0f26786231b55c5b1f344b9db05afa1ede28f70c0c702 - Page: https://openairdocs.org/service-documents/marvel-schebler/sb-18/file/4db0ec6ed6a3 ## Text Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 SB-18_0 Original Issue Date: October 14th, 2010 Page 1 of 4 Distributed by: Manufactured By: 1. Applicability: Except as noted in the “Exempted MFB Carburetors” section below, this service bulletin applies to all machined from billet (MFB) HA-6™ carburetors, including but not necessarily limited to the following part numbers (including all dash numbers) : 10-5219-XX, 10 -5224-XX, 10 -5230-XX, 10 -5235-XX, 10 -5253-XX, 10 -5255-XX, 10 - 5283-XX, 10 -6001-XX, 10 -6019-XX, and 10 -6030-XX, regardless of whether the carburetor is new, rebuilt, overhauled or used, and regardless of what agency performed service on the carburetor(s) in the past . MFB HA-6™ carburetors are found on various Lycoming engine models , possibly on engines made by other manufacturers, and on certificated and non -certificated aircraft of various types . This bulletin applies only to MFB HA-6™ carburetors, it does NOT apply to die -cast HA-6™ carburetors. (See Figure 3 below) Exempted MFB Carburetors – This bulletin does not apply to MFB HA-6™ carburetors manufactured by Marvel -Schebler Aircraft Carburetors LLC (MSA), formerly known as Volare Carburetors LLC and having a serial number listed below. This SB likewise does not apply to any MFB HA -6™ carburetors that MSA service d after October 10, 2010, or to any MFB HA-6™ carburetor bearing: A. “IC” number of 17 or higher on the data plate; B. One of the following or higher serial numbers stamped on the carburetor data plate in cases where the original data plate and original carburetor body combination remains unchanged; Marvel-Schebler Aircraft Carburetors LLC 125 Piedmont Avenue Gibsonville, N.C. 27249, USA Phone: 336-446-0002 // 0005 Fax: 336-446-0007 Email: customerservice@msacarbs.com Website: www.msacarbs.com EMERGENCY Service Bulletin: SB-18 Original Date: October 14th, 2010 SUBJECT: LOOSE MIXTURE SLEEVES - BEFORE FURTHER FLIGHT- AVOID SERIOUS RISK OF INJURY OR DEATH MN353303 MS385901 VC213901 VC307001 VN041603 VN067103 VN148901 MN353304 MS392501 VC224401 VC334201 VN041604 VN091501 VN158301 MN353305 MS392901 VC230501 VC346701 VN041605 VN091502 VN226403 MN382201 MS392902 VC238401 VC356501 VN041606 VN091503 VN244301 MS357901 MS392903 VC242401 VN026601 VN041607 VN091504 VN244305 ### Page 2 SB-18_0 Original Issue Date: October 14th, 2010 Distributed by: Manufactured By: C. The letters NWP and/or 8-08 (or numbers representing a month and year later than August 2008) stamped in the airbox flange and/or the engine flange gasket surface. (See Figure 1), or; D. A laser marking affixed to the carburetor by Marvel-Schebler® on the bottom of the carburetor float bowl as shown in Figure 2 indicating that the carburetor is in compliance with this service bulletin. MS364001 VC140601 VC242402 VN026602 VN041609 VN091505 VN292901 MS366301 VC140602 VC249201 VN026603 VN041610 VN091506 VN297501 MS366501 VC140701 VC249202 VN026604 VN043801 VN091507 VN298301 MS370501 VC171301 VC249203 VN026605 VN043802 VN091508 VN313804 MS370503 VC171401 VC249204 VN026606 VN043803 VN111203 VN313805 MS372301 VC181101 VC249205 VN026607 VN043804 VN111204 VN314601 MS378301 VC181102 VC260801 VN026608 VN043805 VN111205 VN314602 MS385201 VC181103 VC260802 VN041001 VN043806 VN134001 VN326701 MS385202 VC210701 VC264101 VN041201 VN067101 VN134003 VN326703 MS385203 VC213401 VC264102 VN041601 VN067102 VN134004 VN326704 VN326705 Page 2 of 4 Figure 1 NOTE: If the carburetor body has been replaced, the serial number is not exempt. [The remainder of this page is intentionally left blank] ### Page 3 SB-18_0 Original Issue Date: October 14th, 2010 Distributed by: Manufactured By: CAUTION: Some over -haulers have substituted data plates bearing their own names and/or logos on carburetors originally manufactured by M SA or its predecessors. Such obfuscation of the actual manufacturer of an aircraft component can lead to confusion as to wh at service bulletins and or Airworthiness Directives apply to what units (see MSA Service Bulletin SB-16). Regardless of what name or logo appears on the data plate, this service bulletin applies to every MFB HA -6™ carburetor ori ginally manufactured by MSA or its predecessors unless it is specifically exempted above. NOTE: Machined from billet HA -6™ carburetors can be identified by their faceted, milled surfaces and their golden color, see Figure 3 & Figure 4 below. Do not confuse MFB HA-6™ carburetors with die-cast HA-6™ carburetors. GOLD GREY DIE CAST BODY (Smooth Body) MACHINED FROM BILLET BODY (Faceted Body) I.C. NUMBER SERIAL NUMBER Figure 4 Page 3 of 4 Figure 3 Figure 2 ### Page 4 SB-18_0 Original Issue Date: October 14th, 2010 Distributed by: Manufactured By: 2. Reason: Marvel-Schebler® has discovered a very dangerous problem involving loose mixture control sleeves or sleeves that mig ht become loose and is issuing this SB to inform over-haulers, owners, and operators of serious issues with certain MFB HA-6™ carburetors. 3. Background: This service bulletin is prompted by a reported in -flight loss of engine power resulting in the forced landing of an aircraft equipped with a made from billet HA-6™ carburetor. Upon inspection, Marvel-Schebler™ determined that the carburetor’s mixture control sleeve was loose and had rotated in the carburetor body. If a mixture sleeve rotates sufficiently it will interrupt fuel flow to the engine. 4. Procedure: A. For every affected MFB HA-6™ carburetor installed on an aircraft, prior to further flight: i. Remove the carburetor and send it to Marvel-Schebler® for inspection and possible repair before re-installing on the aircraft; ii. Replace the carburetor with a serviceable MFB HA-6™ carburetor of the proper part number that is exempt from this SB; or, iii. Replace the carburetor with a serviceable die-cast HA-6™ carburetor of the proper part number. B. For every affected MFB HA-6™ carburetor in inventory or otherwise not installed on an aircraft, prior to releasing such carburetors for flight, submit such carburetors to Marvel-Schebler® for inspection and possible repair. 5. Voiding of Warranty and Waiver of Liability : Operation of a carburetor in which other than genuine Marvel-Schebler® approved parts are installed voids any otherwise applicable warranty and constitutes a complete and total waiv er to the extent permitted by law of any and all rights the owner, operator and/or service facility or repairer may have had to hold Marvel-Schebler Aircraft Carburetors LLC responsible or liable for the malfunction or failure of such an aviation carburetor. 6. Safety First: Marvel-Schebler® is a customer-service oriented company committed to technical innovation in pursuit of aviation safety. While Marvel-Schebler® has no authority to compel owners to act responsibly and take prudent action to insure their own safety and the safety of others, Marvel-Schebler® believes compliance with this EMERGENCY Service Bulletin is important and will help to insure safer, better maintained and better performing products. 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