AD 89-24-01 R1
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Continental Motors | TSIO-520-B | TELEDYNE CONTINENTAL MOTORS (TCM) Models TSIO-520B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, and VB Engines |
| engine | Continental Motors | TSIO-520-BB | TELEDYNE CONTINENTAL MOTORS (TCM) Models TSIO-520B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, and VB Engines |
| engine | Continental Motors | TSIO-520-D | TELEDYNE CONTINENTAL MOTORS (TCM) Models TSIO-520B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, and VB Engines |
| engine | Continental Motors | TSIO-520-DB | TELEDYNE CONTINENTAL MOTORS (TCM) Models TSIO-520B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, and VB Engines |
| engine | Continental Motors | TSIO-520-E | TELEDYNE CONTINENTAL MOTORS (TCM) Models TSIO-520B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, and VB Engines |
| engine | Continental Motors | TSIO-520-EB | TELEDYNE CONTINENTAL MOTORS (TCM) Models TSIO-520B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, and VB Engines |
| engine | Continental Motors | TSIO-520-J | TELEDYNE CONTINENTAL MOTORS (TCM) Models TSIO-520B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, and VB Engines |
| engine | Continental Motors | TSIO-520-JB | TELEDYNE CONTINENTAL MOTORS (TCM) Models TSIO-520B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, and VB Engines |
| engine | Continental Motors | TSIO-520-K | TELEDYNE CONTINENTAL MOTORS (TCM) Models TSIO-520B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, and VB Engines |
| engine | Continental Motors | TSIO-520-KB | TELEDYNE CONTINENTAL MOTORS (TCM) Models TSIO-520B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, and VB Engines |
Unsafe Condition
Failure of scavenge oil pump gears which could result in total loss of engine power.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect gear teeth for a drill point as shown in Figure 1 of TCM Service Bulletin M90-6. If the drill point is present or absent but fails a Rockwell hardness test, replace gears with serviceable part numbers 649157 or 649159. Make an appropriate log book entry.
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Compliance Time
Within 500 flight hours after the effective date of this AD, or at the next maintenance event after the effective date during which the scavenge oil pump gears are removed from the engine, whichever occurs first.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
TELEDYNE CONTINENTAL MOTORS (TCM) Models TSIO-520B, BB, D, DB, E, EB, J, JB, K, KB, N, NB, UB, and VB engines equipped with scavenge oil pump gears part numbers 635334, 639388, 649157, and 649159, excluding engines with starter adapter P/N 642085A4 or 642085A5, engines with serial numbers in the AD's Appendix, or engines with a starter adapter pulley for an air conditioner compressor drive.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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