# AD 81-24-06: Engine Driven Fuel Pumps - Type: Airworthiness directive - Status: Current - Products: Continental Motors GTSIO-520-C, GTSIO-520-D, GTSIO-520-E, GTSIO-520-H, GTSIO-520-L, GTSIO-520-M, GTSIO-520-N, IO-520-A, IO-520-B, IO-520-BA, IO-520-BB, IO-520-C and 42 more - Effective: November 23, 1981 - Superseded by: Nothing supersedes this AD - Product type: Engine - Amendment: 39-4260 - Registered aircraft: 14,864 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C1D0DA9F8CF100578625684000684EED.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/81-24-06 ## The airworthiness directive 81-24-06 TELEDYNE CONTINENTAL MOTORS: Amendment 39-4260. Applies to Models IO-520, TSIO-520 and GTSIO-520 (except GTSIO-520-F and K) engines equipped with engine driven fuel pumps serial numbers I0178XX through A0280XX, factory new or rebuilt engines which were assembled between September 1, 1978, through July 31, 1980, or fuel pumps which were replaced during that time. The first characters of the fuel pump serial numbers reflect the date of manufacture. The first letter designates the month of manufacture starting with "A" for January, "B" for February, etc. The second and third digits designate the day of build (01 thru 31). The fourth and fifth digits indicate the year of build. Subsequent digits indicate manufacturing sequence number of pump on a given day. Compliance required as indicated unless already accomplished. To prevent possible fuel leakage and potential fire hazard, accomplish the following: (a) Within 10 hours time in service after the effective date of this AD and thereafter at intervals not to exceed 10 hours time in service until (b) is accomplished, visually check the fuel pump for evidence of fuel leaks from between the pump segments. If a leak is detected or fuel stains are present, (b) must be accomplished prior to further flight. (b) Within 50 hours time in service after the effective date of this AD, accomplish the following: (1) Remove safety wire from the four fuel pump through bolts. (2) Torque the through bolts evenly in diagonally opposite pairs to 30 in-lbs. ( 1 in-lb.). (3) Resafety wire through bolts. (4) Upon completion of the above steps, place mixture control in "idle cutoff," pressurize the fuel system with the aircraft boost pump, and inspect for fuel leaks. If a fuel leak still exists, overhaul or replace the pump as appropriate. (c) If fuel leaks were present before retorquing the bolts as required in paragraph (b), then during each of the next five preflights, place the mixture control in "idle cutoff," pressurize the fuel system with the aircraft boost pump and check for fuel leaks or evidence of fuel leaks. If evidence of a fuel leak exists, overhaul or replace the pump as appropriate. This paragraph does not apply if the fuel pump was overhauled or replaced due to compliance with paragraph (b). (d) The checks required by paragraphs (a) and (c) may be accomplished by a certificated pilot as authorized by FAR 43.3(h). (e) Make appropriate maintenance record entries. Upon submission of substantiating data through an FAA Aviation Safety Inspector, the Chief, Engineering and Manufacturing Branch may adjust the inspection intervals. An equivalent method of compliance may be approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, Southern Region. Teledyne Continental Motors Service Bulletin M-80-26, Revision 1, applies to this subject. This amendment becomes effective November 23, 1981. ## Affected data sheets (3) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS E8CE](https://openairdocs.org/tcds/E8CE): Continental Aerospace Technologies, Inc.; names 30 of 31 models: TSIO-520-BB, TSIO-520-B, TSIO-520-P, TSIO-520-R, TSIO-520-AF, TSIO-520-M, TSIO-520-J, TSIO-520-A… - [TCDS E5CE](https://openairdocs.org/tcds/E5CE): Continental Aerospace Technologies, Inc.; names 17 of 18 models: IO-520-NB, IO-520-BA, IO-520-A, IO-520-B, IO-520-P, IO-520-C, IO-520-L, IO-520-N… - [TCDS E7CE](https://openairdocs.org/tcds/E7CE): Continental Aerospace Technologies, Inc.; names 7 of 10 models: GTSIO-520-E, GTSIO-520-D, GTSIO-520-C, GTSIO-520-M, GTSIO-520-N, GTSIO-520-L, GTSIO-520-H ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 14,864 (0 by airframe model, 14,864 by engine model) - Makers: Cessna 7,842, Beech 6,081, Bellanca 469, Piper 194, Raytheon 69, Aero Commander 67, Navion 43, Mooney 16, Meyers Industries 11, Ryan 10 Models with the most aircraft: - [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series): 9,486 aircraft (engine model) - [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series): 4,064 aircraft (engine model) - [Continental GTSIO-520-C](https://openairdocs.org/engine/continental-gtsio-520-c): 387 aircraft (engine model) - [Continental GTSIO-520 series](https://openairdocs.org/engine/continental-gtsio-520-series): 178 aircraft (engine model) - [Continental IO-520-D](https://openairdocs.org/engine/continental-io-520-d): 95 aircraft (engine model) - [Continental IO-520-F](https://openairdocs.org/engine/continental-io-520-f): 80 aircraft (engine model) - [Continental TSIO-520-M](https://openairdocs.org/engine/continental-tsio-520-m): 60 aircraft (engine model) - [Continental TSIO-520-NB](https://openairdocs.org/engine/continental-tsio-520-nb): 52 aircraft (engine model) - [TCM Cont TSIO-520 series](https://openairdocs.org/engine/tcm-cont-tsio-520-series): 49 aircraft (engine model) - [Lycoming IO-520 series](https://openairdocs.org/engine/lycoming-io-520-series): 49 aircraft (engine model) - [Continental IO-520-BB](https://openairdocs.org/engine/continental-io-520-bb): 44 aircraft (engine model) - [Continental TSIO-520-UB](https://openairdocs.org/engine/continental-tsio-520-ub): 27 aircraft (engine model) - [Continental IO-520-BA](https://openairdocs.org/engine/continental-io-520-ba): 25 aircraft (engine model) - [Continental TSIO-520-R](https://openairdocs.org/engine/continental-tsio-520-r): 22 aircraft (engine model) - [Continental TSIO-520-WB](https://openairdocs.org/engine/continental-tsio-520-wb): 19 aircraft (engine model) - [Continental TSIO-520-C](https://openairdocs.org/engine/continental-tsio-520-c): 17 aircraft (engine model) - [Continental GTSIO-520-L](https://openairdocs.org/engine/continental-gtsio-520-l): 16 aircraft (engine model) - [Continental IO-520-B](https://openairdocs.org/engine/continental-io-520-b): 16 aircraft (engine model) - [Continental TSIO-520-P](https://openairdocs.org/engine/continental-tsio-520-p): 12 aircraft (engine model) - [Continental IO-520-L](https://openairdocs.org/engine/continental-io-520-l): 11 aircraft (engine model) All 52 models: https://openairdocs.org/ad/81-24-06/models.md Every aircraft: https://openairdocs.org/ad/81-24-06/aircraft.md Its text cites no advisory circulars or STCs. --- 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.