MIL-DTL-83420 Wire Rope, Flexible, For Aircraft Control, General Specification ForThis specification covers the requirements for carbon steel and corrosion resistant steel aircraft control flexible wire rope. Type I wire rope will be capable of operation within a -65 degrees F to +250 degrees F \(-54 degrees C to +121 degrees C\) temperature range in wind, dust, fuel, and oil spills, in wash-down and other environmental stresses and aircraft experiences. Type II wire rope will be capable of operation within a -65 degrees F to +200 degrees F \(-54 degrees C to +94 degrees C\) temperature range in wind, dust, fuel, and oil spills, in wash-down and other environmental stresses and aircraft experiences.

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MIL-DTL-83420M

hole drilled to a diameter increased as shown in table I under "Allowable increase in diameter at

cut end" or by using a shadowgraph with suitable magnification. The allowable increase in

diameter shall be applied to the actual diameter of the wire rope being tested.

4.4.3 Breaking strength type I, composition A and B. A specimen for each size and

construction of wire rope shall be selected from the sample from each lot. The specimen shall be

no less than 24 inches in length, and where necessary, swaged terminals conforming to

MIL-DTL-781 (do not use ball end fittings) and accompanying hardware may be used to

facilitate installation of the specimen in the jaws of the testing machine. The length of wire rope

sample under load shall be no less than 10 inches. The breaking strength shall be determined by

use of a tensile testing machine in accordance with applicable requirements of ASTM E 8. The

breaking strength shall conform to the requirement of table I. In case of failure due to an

unsatisfactory end termination, the test will be disregarded and a new test conducted.

4.4.4 Endurance testing for type I. The test set-up for the endurance tests for all type I

wire rope shall conform to figure 1. The total travel of the wire rope in one direction shall be

13.5 inches. The test sheaves shall be made of steel and shall conform to the dimensions of

figure 2 and the individual wire diameters in table VI. The application of lubricant to the

endurance test sample, in addition to the lubricant applied during the manufacture of wire rope,

shall not be permitted either before or during the endurance test.

4.4.4.1 Endurance testing at �65�F (-54�C) for type I, composition A. An endurance test

at -65�F (-54�C) shall be conducted for each type I, composition A, wire rope diameter and

construction specified in 4.4.4. The number of reversals and tension loads shall be as indicated

in table III. After the endurance test at -65�F (-54�C), a test specimen that is that portion of the

wire rope that passes over the test sheave during the endurance test shall be selected for breaking

strength tests. From this specimen, two samples representing the top and bottom sheave of the

specimen shall be subjected to a breaking strength determination as specified in 4.4.3, except the

breaking strength of each sample shall be equal to or greater than that specified in table III.

4.4.4.2 Endurance test at room temperature for type I, composition A and B. An

endurance test at room temperature shall be conducted for each type I, composition A and B,

wire rope diameter and construction as specified in table III. The number of reversals and

tension loads shall be as indicated in table III. After the endurance test at room temperature, a

test specimen that is that portion of the wire rope that passes over the test sheave during the

endurance test shall be selected for breaking strength tests. From this specimen, two samples

representing the top and bottom sheave of the specimen shall be subjected to a breaking strength

determination as specified in 4.4.3, except the breaking strength of each sample shall be equal to

or greater than that specified in table III.

4.4.5 Endurance testing for type II. The test set-up for the endurance tests of type II

nylon jacketed wire rope shall conform to figure 1. The total travel of the wire rope in one

direction shall be 13.5 inches. The test sheaves shall be made of steel and shall conform to the

dimensions of figure 2 and the individual wire diameters in table VII which conform to the O.D.

size of the nylon coating, and test loads which conform to the wire rope size.