MIL-M-81392 Marker, Location, Marine Mk 25 And Mods 2 And 3This specification covers the manufacture, assembly, preparation for delivery of the Marker, Location, Marine MK 25 and Mods 2 and 3, and the methods of examination and tests upon which product acceptance shall be based. The marker consists of an aluminum body containing a pyrotechnic composition which produces a yellow flame and white smoke when electrically initiated by Mk 13 Mod O Electric Squib which is activated by a Mk 72 Mod 1 Water Activated Battery. The base of the marker contains a safe-arm feature that seals the battery cavity. The marker is classified as Class B Explosives \( Code of Federal Regulations 49 CFR 71-78\) and IIC Explosives \(Coast Ward Rules and Regulations for Military Explosives and Hazardous Munitions CG 1.08\).

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17

MIL-M-81392(AS)

4.3 Tests. Random samples of markers shall be selected and tested as

specified in 4.1.1 or 4.1.2 as applicable.

4.3.1 Performance tests.

4.3.1.1 Sealing test. The marker shall be tested in a water tank

equipped for observation under vacuum.

CAUTION: The water tank shall be equipped so that the

marker must be raised above the water level while

still under vacuum before releasing the vacuum

and removing the marker.

The uppermost surface of the marker shall be submerged 2 to 6 inches below

the water surface and subjected to a vacuum of 6.0 1.0 inches of mercury

for a minimum period of 30 seconds. Leakers are indicated by a constant

stream of air bubbles issuing from the marker. Do not mistake the escape

of occluded air for leakage. Defective are markers failing to meet the

requirements of 3.3.1.1.

4.3.1.2 Vent release force test. The marker, in the armed position,

shall have a measured axial force of 1.0 pound applied to each of the two

base plugs. Defectives are markers having one or both base plugs failing

to meet the requirements of 3.3.1.2.

4.3.1.3 Static functioning test. The marker shall be tested by

rotating the cover clockwise from the :"SAFE" position to the extreme

"ARMED" position. Push the two base plugs into the marker by applying

pressure on the base plugs with the thumb and finger.

CAUTION: Markers with base plugs pushed in must be

tested or disposed of if not stored with the

adaptor kit assembled on the marker.

Drop the marker into sea water of sufficient quantity to float the marker.

For each maker tested, record markers failing to function, delay time

from striking the water to emission of smoke and flame and the duration

of smoke and flame emission. Defective are markers failing to meet the

requirements of 3.3.1.3.

4.3.1.4 Flight functioning test. The marker shall be tested by

launching from aircraft. One-half of the markers shall be launched using

an Aero Ejector 1A or 1B and the remainder of the sample shall be gravity

released using the S2F3 Aircraft Store Dispenser and the adaptor kit. All

launchings and drops shall be at an altitude of 500 feet and an indicated

air speed of 150 to 200 knots, into sea water of a depth not less than 12

feet. For each marker tested, record markers failing to function, delay

time from striking the water to emission of smoke and flame and the duration

of smoke and flame emission. Markers that fail to load and eject because of

malfunction of the adaptor kit, ejector or store dispenser shall not be