MIL-DTL-11352K(AT)
extent that a standard white target shall appear unchanged in color when viewed through a
thickness of 2 centimeters (cm) [0.79 inch (in.)] (see 4.6.1).
3.2.3 Plastic. The plastic plies shall meet the requirements of SAE AMS-L-P-391 for
type 1, grade A plastic, except that the material need not be acrylic (see 4.6.1).
3.2.4 Adhesive sealing compound. The adhesive sealing compound shall be silicones,
epoxies, or other sealants meeting the environmental, ballistic, and other pertinent requirements
of this specification, or as specified on the applicable drawing. After application and curing, the
compound shall be waterproof and shall adhere to both materials. It shall be non-shrinking and
shall fill the space between the block and the case assembly. The compound shall be unaffected
by fresh or sea water and shall not flow or become tacky at 71 degrees Celsius (°C) [160 degrees
Fahrenheit (°F)] (see 4.6.1).
3.3 Design and construction. The design and construction of the vision blocks shall be
as specified herein and on the applicable drawings (see 6.2). Vision blocks shall have not less
than five interior plies excluding laser and spall protection elements (see 4.6.1 and 4.6.2).
3.3.1 Assembly details. The outboard ply of the vision block shall be positioned in the
rigid case so that the acute angle is located within 1.6 millimeter (mm) (0.063 in.) from the
adjacent edge of the case. The thickness of the sealing compound between the block and case
shall be 1.6±0.4 mm (0.063±0.016 in.) at all ground edges of the block. The outside edges of the
case shall have a radius of 0.8±0.4 mm (0.031±0.016 in.), and all sharp edges of the block shall
be chamfered to 0.8 to 1.6 mm (0.031 to 0.063 in.) prior to assembly in the case (see 4.6.1
and 4.6.2).
3.3.2 Case. The case for the vision block shall be either metal or plastic as specified in
3.3.2.1 and 3.3.2.2 (see 4.6.1).
3.3.2.1 Metal case (type I). The metal case for vision blocks shall be in accordance with
applicable drawing (see 4.6.1).
3.3.2.2 Plastic case (type II). The plastic case for vision blocks shall be of a glass fiber
base, epoxy resin, low pressure laminated, non-electrical material which is heat resistant to
260 °C (500 °F) or it shall be as specified on the applicable drawing. The material thickness
shall be 2.16±0.25 mm (0.085±0.010 in.) (see 4.6.1).
3.4 Operating requirements. Each vision block shall provide the following functional,
operational, and performance capabilities.
3.4.1 Photopic transmittance. For vision blocks without laser protection filters, the
photopic transmittance shall be greater than 75 percent (%) unless otherwise specified on
applicable drawings. The photopic transmittance of vision blocks with laser filters shall be
greater than 42% (see 4.6.3.1).
4
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business