ISSUED REVISED PAGE NO. REVISION
MO DAY YEAR MO DAY YEAR
05 27 60 11 18 09 1 of 4 AU

©2009 by Lycoming “All Rights Reserved” Lycoming Engines, a division of AVCO Corporati on, a wholly owned subsidiary of Textron Inc. 652 Oliver Street Williamsport, PA. 17701 U.S.A

Tel. 570-323-6181 Fax. 570-327-7101 www.lycoming.com

DATE: November 18, 2009 Service Instruction No. 1009AU (Supersedes Service Instruction No. 1009AT) Engineering Aspects are FAA (DER) Approved

SUBJECT: Recommended Time Between Overhaul Periods

MODELS AFFECTED: All Lycoming Piston Aircraft Engines

The following chart shows the established time betw een overhaul (TBO) for Lycoming piston aircraft engines. TBO’s can be established on engines th at incorporate GENUINE LYCOMING PARTS only, and are not applicable if the engine contains parts ot her than those supplied by Lycoming. Service experience, variations in operating conditions, and frequency of operation are some of the factors taken into
consideration when a TBO is established. Because of variations in the manner in which engines are operated and maintained, Lycoming can give no a ssurance that any individual operator will achieve
the recommended TBO.

Continuous service assumes that the ai rcraft will not be out of servic e for any extended period of time.
Refer to latest revision of Service Letter No. L180 if th e aircraft is to be out of service for a period of time greater than 30 days.

Engine deterioration in the fo rm of corrosion (rust) and th e drying out and hardening of composition materials such as gaskets, seals, flexib le hoses and fuel pump diaphragms can occur if an engine is out of service for an extended period of ti me. Due to the loss of a protective oil film after an extended period of inactivity, abno rmal wear on soft metal bearing surfaces can occur during engine start. Therefore, all engines that do not accumula te the hourly period of time between overhauls specified in this publication are recommende d to be overhauled in the twelfth year.

Engine accessories and propellers may require overhaul pr ior to engine overhaul. Perform overhaul of these components in accordance with the ac cessory manufacturer’s recommendation.

The TBO’s in the chart do not apply to engines e ngaged in crop dusting or other chemical-application flying. Overhaul these engines at 1500-hour interval s or at recommended TBO, whichever is lower.

Reliability and average se rvice life cannot be predicted when an engine has undergone any modification not approved by Lycoming. The TBO’s shown in th e table are recommenda tions for engines as manufactured, without consideri ng any modifications that may a lter the life of the engine. 

# SERVICE INSTRUCTIONISSUED REVISED PAGE NO. REVISION
MO DAY YEAR MO DAY YEAR
05 27 60 11 18 09 2 of 4 AU S.I. 1009 RECOMMENDED TIME BETWEEN OVERHAUL PERIODS

FIXED WING AIRCRAFT Engine Models See Note Hours O-235 Series (except –F, -G, -J) 12 2400 O-235-F, -G, -J 13 2000
O-290-D -------- 2000
O-290-D2 -------- 1500 O-320 Series (except O-320-H) 1,10,11 2000
O-320-H 11 2000 IO-320-A, -E 1,10,11 2000 IO-320-B, -D, -F 4,6,10,11 2000 IO-320-C 2,4,10,11 1800 AIO-320 (160 HP) 6 1600
AEIO-320 Series 6 1600
O-340 Series 1 2000 O-360 Series (except O-360-E, -J2A) 1,4,10,11 2000 O-360-E 4,11 2000
IO-360-L2A 11 2000 IO-360-A, -C, -D, -J (200 HP) 4,5,6,10,11 2000 IO-360-B, -E, -F, -M (180 HP) 1,4,10,11 2000 TO-360-C,-F; TIO-360-C 3,11 1800 TO-360-E (180 HP) 3,4,11 1800 AIO-360 (200 HP) 6 1400 TIO-360-A Series 3,11 1200 AEIO-360 Series (180 HP) 6 1600 AEIO-360 Series (200 HP) 6 1400
IO-390-A 11 2000 O-435; GO-435 -------- 1200 GO, GSO-480; IGSO-480 1 1400 O-540-A, -B, -E4A5 1,10 2000 O-540-E4B5, -E4C5 1,11 2000 O-540-G, -H, -J 10,11 2000 O-540-L3C5D 2,11 2000 IO-540-A, -B (290 HP) 1,10,11 1400 IO-540-C 1,10, 11 2000 IO-540-D 1,10 2000 IO-540-E, -G, -P 1,10,11 1600 IO-540-S, -AA 2,10 1800 IO-540-J, -R 2,10 1800
IO-540-J4A5 10 2000 IO-540-AB1A5, -AC1A5, -AF1A5 11 2000 IO-540-K, -L, -M, -N, -T, -V, -W 10,11 2000
AEIO-540 Series 6 1400
IGO & IGSO-540 Series -------- 1200 TIO-540-V, -W, -AE 3,4,11 2000 TIO-540-C, -AA, -AB, -AF, -AG, -AH, -AJ, -AK 3,4,7,11 2000 TIO-540-A, -F, -J, -N, -R, -S, -U 3,4,11,14 1800 TIO-541-A (320 HP) 3 1300 TIO-541-E (380 HP) 3,9 1600 TIGO-541 (425 HP) 3 1200
IO-580-B1A 11 2000
AEIO-580-B1A 6 1400ISSUED REVISED PAGE NO. REVISION
MO DAY YEAR MO DAY YEAR
05 27 60 11 18 09 3 of 4 AU S.I. 1009 RECOMMENDED TIME BETWEEN OVERHAUL PERIODS (CONT.)

ROTARY WING AIRCRAFT

Engine Models See Note Hours

IO-720 Series 11 1800 O-320-A2C, -B2C 11 2000
HO-360-C1A 11 2000 O-360-C2B,-C2D; HO-360 (except –C 1A); HIO-360-B -------- 1500
O-360-J2A 11 2000 HIO-360-A, -C, -D, -E, -F Series -------- 1500
HIO-360-G1A 11 2000
VO-360-A Series -------- 600 VO-360-B; IVO-360 -------- 1000
VO-435-A Series -------- 1200
VO-435-B Series -------- 1200
TVO-435 Series 3 1000
O-540-F1B5 11 2000
IO-540-AE1A5 11 2000
VO-540 Series 8 1200
IVO-540 Series -------- 600 TVO, TIVO-540 Series 3,8 1200

NOTES

1. Only engines built with 1⁄2 inch dia. exhaust valve stems. Engines of this series with 7/16 inch dia.
exhaust valves should not exceed 1200 hours between overhauls regardless of the type of operation

. New and rebuilt engines built with 1⁄2 inch dia. exhaus t valve stems are identified, respectively, by serial
numbers and date in the latest re vision of Service Instruction No. 1136.

2. These engines are designed to in corporate exhaust turbocharging.

3. Turbochargers may require removal, prior to engine overhaul, for carbon removal and repair.

4. Engines with reverse rotation have same overhau l times as corresponding normal rotation engines.

5. 1200 HOURS: Engines that do not have large main bearing dowels should not be operated more than
1200 hours between overhauls.

1400 HOURS: Engines that have large main beari ng dowels may be operated to 1400 hours between overhauls. These include engines with serial numbers L-7100-51A and up, and L-101-67A and up; engines which are in compliance with the late st revision of Service Bulletin No. 326; and remanufactured engines shi pped after January 26, 1970.

2000 HOURS: Engines that have la rge main bearing dowels and redesi gned camshafts may be operated to 2000 hours between overhauls. These include engine s with serial numbers L-9762-51A and up; IO360-C1E6 engines with serial numbers L-9723-51A a nd up; LIO-360-C1E6 engine s with serial numbers L-524-67A and up; engines that are in compliance with the latest revision of Service Bulletin No. 326
and Service Instruction No. 1263. Re built engines shipped after Oc tober 1, 1972, may be operated to 2000 hours between overhauls except those with serial numbers L- 2349-51A and L-7852-51A which do not have the redesigned camshaft and must not exceed 1400 hours of operating time between overhauls.ISSUED REVISED PAGE NO. REVISION
MO DAY YEAR MO DAY YEAR
05 27 60 11 18 09 4 of 4 AU S.I. 1009 6. The reliability and service life of engines can be detr imentally affected if they are repeatedly operated at alternating high and low power app lications which cause extreme changes in cylinder temperatures. Flight maneuvers which cause engine overspeed also contribute to abnormal wear characteristics that tend to shorten engine life. These factors must be considered to establish TBO of aerobatic engines; therefore it is the responsibility of the operator to determine the percentage of time the engine is used for
aerobatics and establish his own TBO. The maximum recommended is the time specified in this
instruction.

7. TIO-540-C Series engines with se rial numbers L-1754-61 and up, TIO-540- C Series engines that were rebuilt or overhauled at Lycoming Engines, W illiamsport, PA after March 1, 1971, and TIO-540-C series engines that have been modified to incor porate large main bearing dowels as described in the
latest revision of Service Instru ction No. 1225 may be operated to 2000 hours. Engines that do not incorporate this modification must not exceed 1500 hours between overhauls.

8. VO, TVO and TIVO-540 engines built with P/N 77450 connecting rods as described in the latest revision of Service Bulletin No. 371 may be conti nued in service to 1200 hour s. Engines that do not incorporate this new connecting ro d are restricted to 1000 hours for VO-540 models and 900 hours for
TVO and TIVO-540. See latest revision of Servic e Bulletin No. 371 for improved connecting rod assembly.

9. TIO-541-E series engines with se rial numbers L-804-59 and up, rebuilt engines shipped after March 1, 1976, and all engines that incorporate the improved cr ankcases and cylinder assemblies described in the
latest revision to Serv ice Bulletin Nos. 334 and 353 may be ope rated for 1600 hours before overhaul. Engines not in compliance with these requirem ents are limited to 1200 hours recommended time
between overhaul.

10. Some engines in the field have been altered to inco rporate an inverted oil system in order to perform
aerobatic maneuvers. Whenever this m odification is done to an engine, the TBO of the engine must be
determined in the same manner listed for AEIO engines of the same model series.

11. If an engine is being used in “frequent” type service and accumulates 40 hours or more per month, and has been so operated consistently since bei ng placed in service, add 200 hours to TBO time.

12. To qualify for the 2400 hour TBO, high-compression O- 235’s must have the in creased strength pistons (P/N LW-18729). See latest revi sion of Service Letter No. L213.

13. The high-compression O-235-F, -G and -J series do not have the increased-stre ngth pistons (P/N LW18729); therefore, they do not qualify for the 2400 hour TBO.

14. TIO-540-A series engines with serial numbers L- 1880-61 and up, TIO-540-A series engines that were rebuilt or overhauled at Lycoming Engines, Will iamsport, PA after Marc h 1, 1971, and TIO-540-A series engines that have been modified to incor porate large main bearing dowels as described in the
latest revision of Service Instru ction No. 1225 may be operated to 1800 hours. Engines that do not incorporate this modification must not exceed 1500 hours between overhauls.