STABILIZED GLIDE SLOPE INDICATOR SYSTEM (SGSI)

This selection contains information describing each assembly of the mk 1 mod 0 stabilized glide slope indicator(SGSI) system (figure 1-1). Information is also provided which will enable operating personnel to prepare and operate the SGSI system. The information provided in this section is presented under the following topics:

1. Purpose of SGSI system
2. Physical description
3. Operating instructions.

PURPOSE OF GLIDE SLOPE INDICATOR SYSTEM.
The SGSI system is an electro-hydraulic-optical landing aid designed for use on air capable and amphibious assault ships. By use of the stabilized glide slope indicator, a helicopter pilot may visually establish and maintain proper glide slope for safer landing. Later configurations of the equipment include EMI hardening protection.

The glide slope indicator, which is mounted on a stabilized platform, provides a single bar of either green, amber, or red light. The color of a single bar of light indicates to the pilot of the approaching aircraft whether he is above (green), below (red), or on (amber) the correct glide slope. By varying the air-craft altitude in order to keep the amber light bar visible, the pilot maintains the correct glide path to the ship's landing pad. The bar of light is formed by the combined actions of source light, Fresnel lens, and lenticular lens. In order to steady the glide slope indicator with respect to the pitching and rolling motions of the ship, the light cell is mounted on an electro-hydraulic stabilized platform. This equipment uses a local gyro for reference and develops electronic which in turn control hydraulic cylinders that move the platform in an opposite direction to the ship's pitch and roll axes. A failure detection circuit is also provided for the system internal gyro, remote gyro operation and rate lead circuits by direct comparison with the ship gyro pitch and roll signals to reduce platform dynamic errors. The error detection circuits will put the system in not-ready and shut off the GSI light in the event of any system failure. This results in a stable glide slope indicator (GSI) light source presentation.

PHYSICAL DESCRIPTION
A detailed description of the size, weight, electrical requirements, transistor complement and fuse complement of the SGSI system is provided. The assemblies that comprise the SGSI system together with their unit numbers are as follows:

1. Electronics enclosure assembly (F100).

2. Remote control panel assembly (F200).

3. Hydraulic pump assemble (F300)

4. Transformer enclosure assembly (F400)

5. Glide slope Indicator assembly (F500)

6. Stabilized Platform Assembly (F600)

7. Isolation Transformer Assembly (F900)

SIZE and WEIGHT
The size and weight for each assembly of the SGSI system are available upon request.

TECHNICAL CHARACTERISTICS
The technical characteristics of the glide slope indicator and the stabilized platform are available upon request.
 

INPUT POWER REQUIREMENT
The following power sources must be available to operate the SGSI system. The amplitude and frequency of each of the power sources listed must be regulated to within 5 percent of the specified requirements
a. One 115 volt, 60 Hz, single phase, 10 ampere ships emergency power source (Automatic Bus Transfer) under grounded. Nominal draw is 8.5 amperes.
b. One 440 volts, 60 Hz, 3 phase, 5 ampere ships emergency power source (Automatic Bus Transfer) ungrounded. Pump draws 2,7 amps when running.

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