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66-06-03: Connecting Rod Assemblies

FAA order 66-06-03 is an airworthiness directive in force since January 16, 1969. The FAA's subject line: Connecting Rod Assemblies. It names the Lycoming GO-435-C2A, Lycoming GO-435-C2A2, Lycoming GO-435-C2B, Lycoming GO-435-C2B2, Lycoming GO-435C&D series, Lycoming GO-480-B, Lycoming GO-480-B1A6, Lycoming GO-480-B1D, Lycoming GO-480-F4A6, Lycoming GO-480-G1A6, Lycoming GO-480-G1B6, Lycoming GO-480-G1D6, Lycoming GO-480-G2D6, Lycoming GO-480-G2F6, Lycoming GO-480 series, Lycoming GSO-435 SERIE, Lycoming GSO-480-B1J6, Lycoming GSO-580 series, Lycoming HIO-360-A1A, Lycoming HIO-360-B1A, Lycoming HIO-360-B1B, Lycoming HIO-360-C1A, Lycoming HIO-360-C1B, Lycoming IGO-540-B1A, Lycoming IGSO-480-A1E6, Lycoming IGSO-540-B1A, Lycoming IO-320-A1A, Lycoming IO-320-B1A, Lycoming IO-320-B1C, Lycoming IO-320-B2A, Lycoming IO-320-C1A, Lycoming IO-320-E2A, Lycoming IO-320 series, Lycoming IO-360-A1A, Lycoming IO-360-A1B, Lycoming IO-360-A2B, Lycoming IO-360-B1A, Lycoming IO-360-B1B, Lycoming IO-360-B1C, Lycoming IO-360-B1D, Lycoming IO-360-B1E, Lycoming IO-360-C1A, Lycoming IO-360-D1A, Lycoming IO-360 series, Lycoming IO-540-A1A5, Lycoming IO-540-B1A5, Lycoming IO-540-C1B5, Lycoming IO-540-C2C, Lycoming IO-540-C4B5, Lycoming IO-540-D4A5, Lycoming IO-540-E1A5, Lycoming IO-540-E1B5, Lycoming IO-540-G1A5, Lycoming IO-540-G1B5, Lycoming IO-540-G1C5, Lycoming IO-540-J4A5, Lycoming IO-540-K1A5, Lycoming IO-540-K1B5, Lycoming IO-540 series, Lycoming IO-720, Lycoming IO-720-A1B, Lycoming IVO-360-A1A, Lycoming O-145-B2, Lycoming O-145B series, Lycoming O-233, Lycoming O-235, Lycoming O-235-C, Lycoming O-235-C1, Lycoming O-235-C1A, Lycoming O-235-C1B, Lycoming O-235 series, Lycoming O-290, Lycoming O-290-C, Lycoming O-290-D, Lycoming O-290-D2, Lycoming O-290-D2B, Lycoming O-290 series, Lycoming O-320-A1A, Lycoming O-320-A1B, Lycoming O-320-A2A, Lycoming O-320-A2B, Lycoming O-320-A2C, Lycoming O-320-A3A, Lycoming O-320-A3B, Lycoming O-320-A3C, Lycoming O-320-B1A, Lycoming O-320-B1B, Lycoming O-320-B2A, Lycoming O-320-B2B, Lycoming O-320-B2C, Lycoming O-320-B3B, Lycoming O-320-C1A, Lycoming O-320-C2A, Lycoming O-320-C3B, Lycoming O-320-D1A, Lycoming O-320-D2A, Lycoming O-320-D2B, Lycoming O-320-D2C, Lycoming O-320-E1A, Lycoming O-320-E2A, Lycoming O-320-E2B, Lycoming O-320-E2C, Lycoming O-320 series, Lycoming O-340-A1A, Lycoming O-340-B1A, Lycoming O-340 series, Lycoming O-350, Lycoming O-350 series, Lycoming O-360-A1A, Lycoming O-360-A1D, Lycoming O-360-A2A, Lycoming O-360-A2D, Lycoming O-360-A3A, Lycoming O-360-A4A, Lycoming O-360-B1A, Lycoming O-360-B1B, Lycoming O-360-B2A, Lycoming O-360-C1A, Lycoming O-360-C2A, Lycoming O-360-C2C, Lycoming O-360-C2D, Lycoming O-360-D1A, Lycoming O-360-D2A, Lycoming O-360 series, Lycoming O-435A/O-435C, Lycoming O-540-A1A, Lycoming O-540-A1A5, Lycoming O-540-A1B5, Lycoming O-540-A1C5, Lycoming O-540-A1D, Lycoming O-540-A1D5, Lycoming O-540-A2B, Lycoming O-540-A4B5, Lycoming O-540-A4C5, Lycoming O-540-A4D5, Lycoming O-540-B1A5, Lycoming O-540-B1B5, Lycoming O-540-B2B5, Lycoming O-540-B2C5, Lycoming O-540-B4B5, Lycoming O-540-E4A5, Lycoming O-540-E4B5, Lycoming O-540-E4C5, Lycoming O-540-F1B5, Lycoming O-540-J1A5D, Lycoming O-540-J2A5D, Lycoming O-540 series, Lycoming R-680E1, Lycoming R680, Lycoming R680E series, Lycoming R680E3A, Lycoming R680E3B, Lycoming TIO-540-A1A, Lycoming TIO-541-A1A, Lycoming TIO-541 series, Lycoming TVO-435-A1A, Lycoming TVO-435-D1A, Lycoming TVO-435-GIA, Lycoming VO-435-A1F, Lycoming VO-435-B1A, Lycoming VO-435 series, Lycoming VO-540-B1B3, Lycoming VO-540 series engines: about 63,509 aircraft on the U.S. register today across them, though an order usually covers particular versions or serial numbers rather than every one. System: engine.

What it applies to as the FAA lists it

Kind of product
Engine
Makes
Lycoming Engines; Textron Lycoming, AVCO Corporation
Models
GO-435-C2 (O-435-17), GO-435-C2A, GO-435-C2A2, GO-435-C2B, GO-435-C2B1, GO-435-C2B2, GO-435-C2E, GO-435-D1, GO-480-A1A, GO-480-B, GO-480-B1A6, GO-480-B1B, GO-480-B1C, GO-480-B1D, GO-480-C1B6, GO-480-C1D6, GO-480-C2C6, GO-480-C2D6, GO-480-C2E6, GO-480-C3A6, GO-480-D1A, GO-480-E1A6, GO-480-F1A6, GO-480-F2A6, GO-480-F2D6, GO-480-F3A6, GO-480-F3B6, GO-480-F4A6, GO-480-F4B6, GO-480-F6, GO-480-G1A6, GO-480-G1B6, GO-480-G1D6, GO-480-G1H6, GO-480-G2D6, GO-480-G2F6, GSO-435-B, GSO-435-B2, GSO-480-A1A6, GSO-480-A1C6, GSO-480-A2A6, GSO-480-B1A6, GSO-480-B1B6 (O-480-1), GSO-480-B1C6, GSO-480-B1E6,...
Engine series
Lycoming GO-435-C2A 2 aircraft
Lycoming GO-435-C2A2 5 aircraft
Lycoming GO-435-C2B 1 aircraft
Lycoming GO-435-C2B2 5 aircraft
Lycoming GO-435C&D series 130 aircraft
Lycoming GO-480-B 1 aircraft
Lycoming GO-480-B1A6 10 aircraft
Lycoming GO-480-B1D 1 aircraft
Lycoming GO-480-F4A6 1 aircraft
Lycoming GO-480-G1A6 1 aircraft
Lycoming GO-480-G1B6 1 aircraft
Lycoming GO-480-G1D6 7 aircraft
Lycoming GO-480-G2D6 3 aircraft
Lycoming GO-480-G2F6 1 aircraft
Lycoming GO-480 series 246 aircraft
Lycoming GSO-435 SERIE 7 aircraft
Lycoming GSO-480-B1J6 3 aircraft
Lycoming GSO-580 series 2 aircraft
Lycoming HIO-360-A1A 5 aircraft
Lycoming HIO-360-B1A 16 aircraft
Lycoming HIO-360-B1B 2 aircraft
Lycoming HIO-360-C1A 6 aircraft
Lycoming HIO-360-C1B 1 aircraft
Lycoming IGO-540-B1A 9 aircraft
Lycoming IGSO-480-A1E6 1 aircraft
Lycoming IGSO-540-B1A 48 aircraft
Lycoming IO-320-A1A 2 aircraft
Lycoming IO-320-B1A 55 aircraft
Lycoming IO-320-B1C 2 aircraft
Lycoming IO-320-B2A 1 aircraft
Lycoming IO-320-C1A 7 aircraft
Lycoming IO-320-E2A 11 aircraft
Lycoming IO-320 series 1,707 aircraft
Lycoming IO-360-A1A 195 aircraft
Lycoming IO-360-A1B 52 aircraft
Lycoming IO-360-A2B 2 aircraft
Lycoming IO-360-B1A 49 aircraft
Lycoming IO-360-B1B 67 aircraft
Lycoming IO-360-B1C 6 aircraft
Lycoming IO-360-B1D 2 aircraft
Lycoming IO-360-B1E 184 aircraft
Lycoming IO-360-C1A 7 aircraft
Lycoming IO-360-D1A 4 aircraft
Lycoming IO-360 series 8,560 aircraft
Lycoming IO-540-A1A5 16 aircraft
Lycoming IO-540-B1A5 4 aircraft
Lycoming IO-540-C1B5 9 aircraft
Lycoming IO-540-C2C 1 aircraft
Lycoming IO-540-C4B5 179 aircraft
Lycoming IO-540-D4A5 236 aircraft
Lycoming IO-540-E1A5 4 aircraft
Lycoming IO-540-E1B5 4 aircraft
Lycoming IO-540-G1A5 7 aircraft
Lycoming IO-540-G1B5 3 aircraft
Lycoming IO-540-G1C5 3 aircraft
Lycoming IO-540-J4A5 9 aircraft
Lycoming IO-540-K1A5 44 aircraft
Lycoming IO-540-K1B5 17 aircraft
Lycoming IO-540 series 4,218 aircraft
Lycoming IO-720 119 aircraft
Lycoming IO-720-A1B 8 aircraft
Lycoming IVO-360-A1A 2 aircraft
Lycoming O-145-B2 5 aircraft
Lycoming O-145B series 538 aircraft
Lycoming O-233 6 aircraft
Lycoming O-235 14 aircraft
Lycoming O-235-C 31 aircraft
Lycoming O-235-C1 49 aircraft
Lycoming O-235-C1A 2 aircraft
Lycoming O-235-C1B 20 aircraft
Lycoming O-235 series 6,134 aircraft
Lycoming O-290 46 aircraft
Lycoming O-290-C 1 aircraft
Lycoming O-290-D 45 aircraft
Lycoming O-290-D2 59 aircraft
Lycoming O-290-D2B 6 aircraft
Lycoming O-290 series 2,125 aircraft
Lycoming O-320-A1A 20 aircraft
Lycoming O-320-A1B 2 aircraft
Lycoming O-320-A2A 9 aircraft
Lycoming O-320-A2B 180 aircraft
Lycoming O-320-A2C 1 aircraft
Lycoming O-320-A3A 5 aircraft
Lycoming O-320-A3B 12 aircraft
Lycoming O-320-A3C 1 aircraft
Lycoming O-320-B1A 17 aircraft
Lycoming O-320-B1B 3 aircraft
Lycoming O-320-B2A 11 aircraft
Lycoming O-320-B2B 92 aircraft
Lycoming O-320-B2C 55 aircraft
Lycoming O-320-B3B 22 aircraft
Lycoming O-320-C1A 1 aircraft
Lycoming O-320-C2A 2 aircraft
Lycoming O-320-C3B 1 aircraft
Lycoming O-320-D1A 116 aircraft
Lycoming O-320-D2A 72 aircraft
Lycoming O-320-D2B 18 aircraft
Lycoming O-320-D2C 1 aircraft
Lycoming O-320-E1A 3 aircraft
Lycoming O-320-E2A 98 aircraft
Lycoming O-320-E2B 4 aircraft
Lycoming O-320-E2C 11 aircraft
Lycoming O-320 series 27,316 aircraft
Lycoming O-340-A1A 5 aircraft
Lycoming O-340-B1A 1 aircraft
Lycoming O-340 series 60 aircraft
Lycoming O-350 1 aircraft
Lycoming O-350 series 17 aircraft
Lycoming O-360-A1A 600 aircraft
Lycoming O-360-A1D 1,057 aircraft
Lycoming O-360-A2A 38 aircraft
Lycoming O-360-A2D 5 aircraft
Lycoming O-360-A3A 50 aircraft
Lycoming O-360-A4A 63 aircraft
Lycoming O-360-B1A 13 aircraft
Lycoming O-360-B1B 2 aircraft
Lycoming O-360-B2A 3 aircraft
Lycoming O-360-C1A 7 aircraft
Lycoming O-360-C2A 19 aircraft
Lycoming O-360-C2C 6 aircraft
Lycoming O-360-C2D 2 aircraft
Lycoming O-360-D1A 6 aircraft
Lycoming O-360-D2A 4 aircraft
Lycoming O-360 series 1,066 aircraft
Lycoming O-435A/O-435C 135 aircraft
Lycoming O-540-A1A 4 aircraft
Lycoming O-540-A1A5 7 aircraft
Lycoming O-540-A1B5 4 aircraft
Lycoming O-540-A1C5 4 aircraft
Lycoming O-540-A1D 1 aircraft
Lycoming O-540-A1D5 18 aircraft
Lycoming O-540-A2B 2 aircraft
Lycoming O-540-A4B5 2 aircraft
Lycoming O-540-A4C5 1 aircraft
Lycoming O-540-A4D5 7 aircraft
Lycoming O-540-B1A5 1 aircraft
Lycoming O-540-B1B5 1 aircraft
Lycoming O-540-B2B5 27 aircraft
Lycoming O-540-B2C5 13 aircraft
Lycoming O-540-B4B5 40 aircraft
Lycoming O-540-E4A5 9 aircraft
Lycoming O-540-E4B5 21 aircraft
Lycoming O-540-E4C5 15 aircraft
Lycoming O-540-F1B5 299 aircraft
Lycoming O-540-J1A5D 11 aircraft
Lycoming O-540-J2A5D 1 aircraft
Lycoming O-540 series 5,244 aircraft
Lycoming R-680E1 1 aircraft
Lycoming R680 218 aircraft
Lycoming R680E series 225 aircraft
Lycoming R680E3A 1 aircraft
Lycoming R680E3B 13 aircraft
Lycoming TIO-540-A1A 5 aircraft
Lycoming TIO-541-A1A 1 aircraft
Lycoming TIO-541 series 273 aircraft
Lycoming TVO-435-A1A 1 aircraft
Lycoming TVO-435-D1A 2 aircraft
Lycoming TVO-435-GIA 88 aircraft
Lycoming VO-435-A1F 15 aircraft
Lycoming VO-435-B1A 6 aircraft
Lycoming VO-435 series 190 aircraft
Lycoming VO-540-B1B3 3 aircraft
Lycoming VO-540 series 110 aircraft

Dates and paperwork

In force since
January 16, 1969
Docket
Unknown
Status
Current
The FAA's document
Read the order on the FAA's site

The order itself the regulatory text, as published

Show the full text (1,013 characters)
66-06-03 LYCOMING: Amdt. 39-708. Applies to Model IO-360-A1A Engines with Serial Numbers 101-51 through 1231-51A, and All Engines Remanufactured by Lycoming Prior to December 1, 1964. Compliance required as indicated. To prevent further failures of connecting rod assemblies, P/N 74503 and P/N 74308, accomplish the following: (a) Replace connecting rod assemblies P/N 74503 and P/N 74308 with 200 or more hours' time in service on the effective date of this AD with connecting rod assembly P/N 75059 within the next 50 hours' time in service in accordance with Lycoming Service Bulletin No. 302 or later FAA-approved revision. (b) Replace connecting rod assemblies P/N 74503 and P/N 74308 with less than 200 hours' time in service on the effective date of this AD with connecting rod assembly P/N 75059 before the accumulation of 250 hours' time in service in accordance with Lycoming Service Bulletin No. 302 or later FAA-approved revision. Effective March 13, 1966.Revised January 16, 1969.

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 5, 2026. Connections as data: /graph/directive/66-06-03.json · aircraft systems.