FAA orders · airworthiness directive · current

78-23-10: Center Body Bellows Seal Assembly

FAA order 78-23-10 is an airworthiness directive in force since November 7, 1978. The FAA's subject line: Center Body Bellows Seal Assembly. It names the Lycoming AEIO-320-D1B, Lycoming AEIO-320-E1B, Lycoming AEIO-320-E2B, Lycoming AEIO-320 series, Lycoming AEIO-360-A1A, Lycoming AEIO-360-A1B, Lycoming AEIO-360-A1B6, Lycoming AEIO-360-A1D, Lycoming AEIO-360-A2C, Lycoming AEIO-360-B1B, Lycoming AEIO-360-B1F, Lycoming AEIO-360-B1G6, Lycoming AEIO-360-B2F, Lycoming AEIO-360-B4A, Lycoming AEIO-360-H1A, Lycoming AEIO-360 series, Lycoming AEIO-540-D4A5, Lycoming AEIO-540-D4B5, Lycoming AEIO-540 series, Lycoming HIO-360-A1A, Lycoming HIO-360-B1A, Lycoming HIO-360-B1B, Lycoming HIO-360-C1A, Lycoming HIO-360-C1B, Lycoming HIO-360-D1A, Lycoming HIO-360-E1AD, Lycoming HIO-540-A1A, Lycoming IGO-480, Lycoming IGO-540-A1C, 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-D1A, Lycoming IO-320-D1B, Lycoming IO-320-E1A, Lycoming IO-320-E1B, Lycoming IO-320-E2A, Lycoming IO-320-E2B, Lycoming IO-320 series, Lycoming IO-360-A1A, Lycoming IO-360-A1B, Lycoming IO-360-A1B6, Lycoming IO-360-A1B6D, Lycoming IO-360-A1D, Lycoming IO-360-A1D6, Lycoming IO-360-A2B, Lycoming IO-360-A3B6D, Lycoming IO-360-B1A, Lycoming IO-360-B1B, Lycoming IO-360-B1C, Lycoming IO-360-B1D, Lycoming IO-360-B1E, Lycoming IO-360-B1F, Lycoming IO-360-B1F6, Lycoming IO-360-B2E, Lycoming IO-360-B2F, Lycoming IO-360-B4A, Lycoming IO-360-C1A, Lycoming IO-360-C1C, Lycoming IO-360-C1C6, Lycoming IO-360-C1D6, Lycoming IO-360-C1E6, Lycoming IO-360-C1F, Lycoming IO-360-D1A, Lycoming IO-360-E1A, Lycoming IO-360-F1A, 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-D4B5, Lycoming IO-540-D4C5, Lycoming IO-540-E1A5, Lycoming IO-540-E1B5, Lycoming IO-540-G1A5, Lycoming IO-540-G1B5, Lycoming IO-540-G1C5, Lycoming IO-540-G1D5, Lycoming IO-540-J4A5, Lycoming IO-540-K1A5, Lycoming IO-540-K1A5D, Lycoming IO-540-K1B5, Lycoming IO-540-K1C5, Lycoming IO-540-K1E5, Lycoming IO-540-K1F5, Lycoming IO-540-K1G5, Lycoming IO-540-K1G5D, Lycoming IO-540-K1H5, Lycoming IO-540-K1J5, Lycoming IO-540-N1A5, Lycoming IO-540-P1A5, Lycoming IO-540-R1A5, Lycoming IO-540-S1A5, Lycoming IO-540 series, Lycoming IO-540-T4A5D, Lycoming IO-540-V4A5D, Lycoming IO-540-W1A5, Lycoming IO-720, Lycoming IO-720-A1B, Lycoming IO-720-C1B, Lycoming IO-720-D1CD, Lycoming IVO-360-A1A, Lycoming LIO-320-C1A, Lycoming LIO-360-C1E6, Lycoming LTIO-540-F2BD, Lycoming LTIO-540-J2BD, Lycoming TIGO-541-E1A, Lycoming TIGO-541 series, Lycoming TIO-360-C1A6D, Lycoming TIO-360 series, Lycoming TIO-540-A1A, Lycoming TIO-540-A2B, Lycoming TIO-540-A2C, Lycoming TIO-540-C1A, Lycoming TIO-540-F2BD, Lycoming TIO-540-J2BD, Lycoming TIO-540-K1AD, Lycoming TIO-540-R2AD, Lycoming TIO-540-S1AD, Lycoming TIO-540 series, Lycoming TIO-541-A1A, Lycoming TIO-541-E1C4, Lycoming TIO-541 series engines: about 25,735 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: AEIO-320-D1B, AEIO-320-E1A, AEIO-320-E1B, AEIO-320-E2A, AEIO-320-E2B, AEIO-360-A1A, AEIO-360-A1B, AEIO-360-A1B6, AEIO-360-A1C, AEIO-360-A1D, AEIO-360-A2A, AEIO-360-A2B, AEIO-360-A2C, AEIO-360-B1B, AEIO-360-B1D, AEIO-360-B1F, AEIO-360-B1F6, AEIO-360-B1G6, AEIO-360-B2F, AEIO-360-B2F6, AEIO-360-B4A, AEIO-360-H1A, AEIO-540-D4A5, AEIO-540-D4B5, AEIO-540-D4C5, AIO-320-A1A, AIO-320-A1B, AIO-320-A2A, AIO-320-A2B, AIO-320-B1B, AIO-320-C1B, AIO-360-A1A, AIO-360-A1B, AIO-360-A2A, AIO-360-A2B, AIO-360-B1B, HIO-360-A1A, HIO-360-B1A, HIO-360-B1B, HIO-360-C1A, HIO-360-C1B, HIO-360-D1A, HIO-360-E1AD,...
Engine series: Lycoming AEIO-320-D1B 2 aircraft
Lycoming AEIO-320-E1B 6 aircraft
Lycoming AEIO-320-E2B 6 aircraft
Lycoming AEIO-320 series 74 aircraft
Lycoming AEIO-360-A1A 3 aircraft
Lycoming AEIO-360-A1B 1 aircraft
Lycoming AEIO-360-A1B6 11 aircraft
Lycoming AEIO-360-A1D 15 aircraft
Lycoming AEIO-360-A2C 1 aircraft
Lycoming AEIO-360-B1B 2 aircraft
Lycoming AEIO-360-B1F 4 aircraft
Lycoming AEIO-360-B1G6 22 aircraft
Lycoming AEIO-360-B2F 7 aircraft
Lycoming AEIO-360-B4A 5 aircraft
Lycoming AEIO-360-H1A 8 aircraft
Lycoming AEIO-360 series 883 aircraft
Lycoming AEIO-540-D4A5 55 aircraft
Lycoming AEIO-540-D4B5 3 aircraft
Lycoming AEIO-540 series 434 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 HIO-360-D1A 41 aircraft
Lycoming HIO-360-E1AD 9 aircraft
Lycoming HIO-540-A1A 2 aircraft
Lycoming IGO-480 1 aircraft
Lycoming IGO-540-A1C 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-D1A 57 aircraft
Lycoming IO-320-D1B 6 aircraft
Lycoming IO-320-E1A 3 aircraft
Lycoming IO-320-E1B 3 aircraft
Lycoming IO-320-E2A 11 aircraft
Lycoming IO-320-E2B 4 aircraft
Lycoming IO-320 series 1,707 aircraft
Lycoming IO-360-A1A 195 aircraft
Lycoming IO-360-A1B 52 aircraft
Lycoming IO-360-A1B6 141 aircraft
Lycoming IO-360-A1B6D 844 aircraft
Lycoming IO-360-A1D 15 aircraft
Lycoming IO-360-A1D6 191 aircraft
Lycoming IO-360-A2B 2 aircraft
Lycoming IO-360-A3B6D 74 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-B1F 8 aircraft
Lycoming IO-360-B1F6 3 aircraft
Lycoming IO-360-B2E 3 aircraft
Lycoming IO-360-B2F 1 aircraft
Lycoming IO-360-B4A 969 aircraft
Lycoming IO-360-C1A 7 aircraft
Lycoming IO-360-C1C 45 aircraft
Lycoming IO-360-C1C6 64 aircraft
Lycoming IO-360-C1D6 14 aircraft
Lycoming IO-360-C1E6 43 aircraft
Lycoming IO-360-C1F 2 aircraft
Lycoming IO-360-D1A 4 aircraft
Lycoming IO-360-E1A 3 aircraft
Lycoming IO-360-F1A 3 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-D4B5 13 aircraft
Lycoming IO-540-D4C5 1 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-G1D5 26 aircraft
Lycoming IO-540-J4A5 9 aircraft
Lycoming IO-540-K1A5 44 aircraft
Lycoming IO-540-K1A5D 3 aircraft
Lycoming IO-540-K1B5 17 aircraft
Lycoming IO-540-K1C5 1 aircraft
Lycoming IO-540-K1E5 5 aircraft
Lycoming IO-540-K1F5 2 aircraft
Lycoming IO-540-K1G5 48 aircraft
Lycoming IO-540-K1G5D 52 aircraft
Lycoming IO-540-K1H5 2 aircraft
Lycoming IO-540-K1J5 10 aircraft
Lycoming IO-540-N1A5 7 aircraft
Lycoming IO-540-P1A5 4 aircraft
Lycoming IO-540-R1A5 1 aircraft
Lycoming IO-540-S1A5 10 aircraft
Lycoming IO-540 series 4,218 aircraft
Lycoming IO-540-T4A5D 4 aircraft
Lycoming IO-540-V4A5D 39 aircraft
Lycoming IO-540-W1A5 31 aircraft
Lycoming IO-720 119 aircraft
Lycoming IO-720-A1B 8 aircraft
Lycoming IO-720-C1B 1 aircraft
Lycoming IO-720-D1CD 1 aircraft
Lycoming IVO-360-A1A 2 aircraft
Lycoming LIO-320-C1A 1 aircraft
Lycoming LIO-360-C1E6 6 aircraft
Lycoming LTIO-540-F2BD 1 aircraft
Lycoming LTIO-540-J2BD 5 aircraft
Lycoming TIGO-541-E1A 1 aircraft
Lycoming TIGO-541 series 37 aircraft
Lycoming TIO-360-C1A6D 3 aircraft
Lycoming TIO-360 series 15 aircraft
Lycoming TIO-540-A1A 5 aircraft
Lycoming TIO-540-A2B 4 aircraft
Lycoming TIO-540-A2C 6 aircraft
Lycoming TIO-540-C1A 9 aircraft
Lycoming TIO-540-F2BD 4 aircraft
Lycoming TIO-540-J2BD 24 aircraft
Lycoming TIO-540-K1AD 1 aircraft
Lycoming TIO-540-R2AD 1 aircraft
Lycoming TIO-540-S1AD 13 aircraft
Lycoming TIO-540 series 5,079 aircraft
Lycoming TIO-541-A1A 1 aircraft
Lycoming TIO-541-E1C4 9 aircraft
Lycoming TIO-541 series 273 aircraft

Dates and paperwork

In force since: November 7, 1978
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 (1,667 characters)

78-23-10	AVCO LYCOMING:  Amendment 39-3333.  Applies to all fuel injected Lycoming series engines equipped with the following Bendix Fuel Injector Models and Parts List Numbers.
 

Model Number	
Parts List Number 
RSA-5AB1
2524254-5 
2524712-2 
RSA-5AD1
2524054-5 
2524147-7 
2524213-5 
2524291-5 
2524359-4 
2524450-3 
2524550-2 
2524673-2 
2524682-2 
2524742-2 
2524752-1 
RSA-7AA1
2524347-4
RSA-10AD1
2524163-8 
2524163-7A 
2524757-1 
RSA-10DB1
2524275-9 
2524649-3 
RSA-10DB2
2524708-1 
RSA-10ED1
2524273-5A 
2524273-6 
2524298-6 
2524491-3 
2524500-2A 
2524500-3 
2524693-2 
2524709-1 
				
	Compliance required within the next 10 hours in service after the effective date of this AD, unless previously accomplished. 

	To prevent an in-flight power loss due to an over rich condition caused by the failure of the center body bellows seal assembly, replace the center body bellows seal assembly and tube bushing in accordance with Accomplishment and Identification instructions in the applicable Bendix Energy Controls Division Service Bulletin No. RS-52 Rev. 2 revised May 12, 1978, No. RS-53 Rev. 2 revised May 12, 1978, and No. RS-54 Rev. 2 revised May 10, 1978, or FAA approved equivalent. 

	Equivalent methods of compliance must be approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration (FAA), Eastern Region.
 
	As permitted by FARs 21.197 to 21.199, aircraft may be flown to a base where the modification required by this Airworthiness Directive can be accomplished. 

	NOTE:  AVCO Lycoming Service Bulletins No. 428, No. 429 and No. 430 also pertain to this subject. 

	This amendment is effective November 7, 1978.

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/78-23-10.json · aircraft systems.