# AD 93-18-03: Carburetors - Type: Airworthiness directive - Status: Historical - Products: Precision Airmotive Carburetors - Effective: October 29, 1993 - Superseded by: [AD 98-01-06](https://openairdocs.org/ad/98-01-06) - Product type: Appliance - Amendment: 39-8688 - Docket: 92-ANE-07 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/4505AC9E06E2DFED86256A410057B00E.0001 - DRS record last changed: August 7, 2025 - Page: https://openairdocs.org/ad/93-18-03 ## The airworthiness directive 93-18-03 PRECISION AIRMOTIVE CORPORATION: Amendment 39-8688. Docket 92-ANE-07. Applicability: Precision Airmotive (formerly Facet Aerospace Products and Marvel-Schebler) Model MA-3A, MA-3PA, MA-3SPA, and MA-4SPA carburetors installed on but not limited to Textron Lycoming Model O-235, O-290, and O-320 series engines, and Teledyne Continental A-65, A-75, C-75, C-85, C-90, C-115, C-125, C-145, O-200, and O-300 series engines installed on but not limited to normally aspirated piston engine powered aircraft manufactured by Cessna, Piper, Beechcraft, and Mooney. Compliance: Required as indicated, unless accomplished previously. To prevent disruption of fuel flow to the engine resulting in engine power loss, or engine failure, accomplish the following: (a) At the next annual inspection after the effective date of this AD, inspect the carburetor to determine if a two-piece venturi is installed. Carburetors that have the letter "V" stamped or etched on the lower portion of the data plate, or that have a black Precision Airmotive data plate, already contain a one-piece venturi and do not require further action. (1) If a two-piece venturi is installed, at each annual inspection after the effective date of this AD, inspect the carburetor to determine if the primary venturi is loose or missing. If either of these conditions is found, prior to further flight, repair the carburetor by installing a one-piece venturi in accordance with the Accomplishment Instructions of Precision Airmotive Service Bulletin (SB) No. MSA-2, Revision 1, dated November 11, 1991. (2) At the next carburetor removal for overhaul or repair, but not later than 48 months after the effective date of this AD, whichever occurs first, if a two-piece venturi is installed, replace with a one-piece venturi in accordance with the Accomplishment Instructions of Precision Airmotive SB No. MSA-2, Revision 1, dated November 11, 1991. (b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office. The request should be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Seattle Aircraft Certification Office. NOTE: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Seattle Aircraft Certification Office. (c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (d) The inspection and replacement shall be done in accordance with the following service bulletin: Document No. Pages Revision Date Precision Airmotive SB No. MSA-2 1-3 1 November 11, 1991 Total Pages: 3. 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 Precision Airmotive Corporation, 3220 100th St. SW, Bldg E, Everett, WA 98204. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street NW., suite 700, Washington, DC. (e) This amendment becomes effective on October 29, 1993. ## Registered aircraft it may apply to (OpenAirDocs) No registered aircraft matched the models it names. ## Related documents - [AD 98-01-06](https://openairdocs.org/ad/98-01-06): Carburetors · Continental Motors A-65-1, A-65-12, A-65-12F and 184 more. Effective Feb 13, 1998. Supersedes this AD Its text cites no advisory circulars or STCs. ## NTSB investigations that cite this AD (2) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB MIA98LA144](https://openairdocs.org/ntsb/MIA98LA144), Apr 26, 1998: Piper PA-18 (N225NY), St. Petersburg, FL, substantial damage. Probable cause: The intentional operation of the airplane by the pilot and the company/operator with the known deficiencies in equipment (worn carburetor). Also, the poor preflight planning by the pilot for his… - [NTSB SEA95LA083](https://openairdocs.org/ntsb/SEA95LA083), Apr 19, 1995: Cessna 150J (N60886), Cashmere, WA, substantial damage. Probable cause: LOSS OF ENGINE POWER DUE TO UNDETERMINED REASONS. A FACTOR CONTRIBUTING TO THE ACCIDENT WAS ROUGH TERRAIN. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.