80-25-06 R1 TELEDYNE CONTINENTAL MOTORS: Amendment 39-3984 as amended by Amendment 39-4061. Applies to Models GTSIO-520-L, serial numbers 608324 through 608627; GTSIO-520-M, serial numbers 606619 through 606890; and GTSIO-520-N, serial numbers 610001 through 610107, engines with 100 hours or less total time in service on the effective date of this AD, installed on but not limited to certain Cessna Models 404 and 421C airplanes certificated in all categories.
Compliance required as indicated, unless already accomplished.
To prevent engine failure due to loss of engine oil pressure, damage due to contaminated oil, and propeller shaft damage resulting from a malfunctioning thrust washer accomplish the following:
(a) Before each flight and immediately after each flight until the accumulation of 100 hours total time in service, perform a special oil pressure check to determine the oil pressure with engine power at the same level as the magneto check. If oil pressure fluctuatesor is less than 30 psi, accomplish paragraphs (b)(1) and (b)(2) before further flight. This oil pressure check may be accomplished by the pilot as provided in FAR 43.3(h).
(b) Prior to the next flight and at each oil change until the accumulation of 100 hours total time in service:
(1) Remove the oil filter, disassemble the canister, and inspect the paper element between the pleats to determine the quantity of metallic material visually and by using a clean magnet. If total metallic contaminants are in excess of the quantity necessary to cover a 1/4 inch diameter surface, before further flight take the necessary maintenance action to replace those parts that are malfunctioning. NOTE: Exercise caution to prevent contamination of the filter element during disassembly.
(2) Inspect to determine the end clearance (shaft end play) of the propeller drive shaft with engine at ambient temperature. If axial movement is in excess of .020 inch, before further flight take necessarymaintenance action to replace those parts that are malfunctioning.
(c) Prior to the next flight, inspect the engine and airplane records and change oil if necessary to ensure that SAE No. 50 oil is installed for ambient temperatures above 40 degrees F or SAE No. 30 oil is installed for ambient temperatures below 40 degrees F.
(d) Upon or before the accumulation of 25 hours, 50 hours and 100 hours total time in service, change oil and oil filter. Do not use multiviscosity oils within the first 100 hours time in service.
(e) Make appropriate maintenance record entry when accomplishing each requirement of this AD.
The airplanes equipped with affected engines may be flown in accordance with FAR 21.197 to a location where the AD compliance procedures can be accomplished.
An equivalent method of compliance may be approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, Southern Region.
NOTE: Continental Motors Service Bulletin NO. M80-30, dated December 10, 1980, pertains to this subject.
Amendment 39-3984 became effective December 5, 1980.
This amendment 39-4061 becomes effective March 23, 1981.