MIL-J-26149 Jack, Hydraulic, Aircraft Maintenance, General Specification ForThis specification covers the general requirements for weapon systems hydraulic jacks as used with all types of military aircraft.

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MIL-J-26149E

4.3.2 Horizontal test loads. The cycles and directions of forces of the horizontal test loads shall be as specified herein. The horizontal loads shall be applied to the jack through the jack pad socket and adapter in all

tests. The jack shall be so positioned for maximum stability that the line of

action of a leg is directed to be opposite to the direction of the horizontal load.

4.3.2.1 Airframe (Tripod) jack. The load shall be applied toward an opposite leg. The load shall be rotated 120° for a load test on each leg. Twenty cycles shall be directed to each leg. The jack shall be assembled with all leg extensions for this test.

4.3.2.2 Landing-gear (axle) jack. The load shall be applied along the center line of the major and minor axes with respect to the jack base. Thirty cycles shall be directed to each axis as applicable.

4.3.2.3 Cantilever (axle) jack. The load shall be applied to the jack pad perpendicular to and fore and aft along the lateral and longitudinal axis. Fifteen cycles shall be directed to each axis for a total of sixty cycles.

4.3.2.4 Adapter. For these load tests the adapter used shall be designed and installed in the test equipment in accordance with the requirements of MS33559. This adapter shall be of the correct type (size) to accept the

socket which is mounted on top of the jack.

4.3.3 Vertical loads. Vertical loads (see MS33559) shall be applied to the jack through the jack pad socket and shall be colinear with the longitudinal centerline of the ram/cylinder assembly with the jack resting on a level surface.

4.3.4 Hydraulic fluid pumping source. The integral hydraulic pumping system shall be employed for all load lifting tests specified herein, except

4.6.5.1.

4.4 First Article Inspection. A first article inspection and test shall be required on jacks which are to be used with military aircraft.

4.4.1 Test sample. One jack shall be subjected to the first article tests and inspection specified in 4.4.2 and defined in 6.5.

4.4.2 First article tests. First article tests shall consist of all tests described under 4.6.

4.4.3 First Article Test Results. For all first article tests the method of the test and the test results shall be evaluated by the assigned representative of the Government. After the validation of the test results they shall be maintained for use as the reference for all subsequent quality conformance tests.