CHAPTER 1. INTRODUCTION - TM-55-4920-425-13-P0006

TM 55-4920425-13&P

CHAPTER 1

INTRODUCTION

Section I. GENERAL INFORMATION

1-1. Scope. This manual covers operation and service instructions necessary for maintenance of the Tester, Gyro

Indicator, Pitch and Roll (refer to fig. 1-1). The unit is designed for testing aircraft gyro instrument indicators and is

capable of simulating rates of loop and turn, attitudes of dive and climb, and loops in pitch and roll. Types of instruments

that can be tested are directional heading indicators, directional gyro transmitters, attitude horizontal indicators, and any

other type gyro indicators or transmitters having a diameter not exceeding 6 inches.

1-2. Forms and Records. Maintenance forms, records, and reports which are to be used by maintenance personnel at

all maintenance levels are listed in and prescribed by TM 38-750.

1-3. Destruction of Army Material to Prevent Enemy Use. Procedures for destroying Army material to prevent enemy

use are listed in TM 750-244-1-4.

Section II. DESCRIPTION AND LEADING PARTICULARS

1-4. Description. The Tester, Gyro Indicator, Pitch and Roll consists of a motor-driven table which mounts a gimbal

ring and instrument gyro mounting plate. The table and its mechanical drive system is mounted in a cradle which is

mounted on a cast aluminum base with four leveling screws. The 12 inch diameter table is cast aluminum with a

precision ground surface and machined rim which is divided from 0 to 360 degrees in one degree increments. An index

mounted on the cradle provides for proper orientation. Provision is made to connect power to an instrument mounted on

the gimbal through a series of connectors on the table rim which are connected to matching connectors on the rear panel

of the cradle through slip rings. The pneumatic power transfer system conducts reference pressure or vaccum applied to

a pipe fitting through the rear panel of the cradle and the main drive shaft to an outlet on the rim of the table adjacent to

the electrical outlets. The cradle and/or gimbal may be rotated to 90 degrees from normal. A locating and locking pin is

provided to lock either in the 90 degrees position. Two circular levels, one mounted on the gimbal ring and the other on

the gimbal support plate, allow for proper leveling of the unit. A vibrator motor, mounted in the cradle section, provides

fixed vibration frequency to the instrument mounting. This is con trolled by a switch on the front panel. A clutch

incorporated in the drive system with front panel control allows for leveling and positioning of the test instrument.

1-5. Leading Particulars.

Power Source:

117V, 60 HZ

Power Consumption:

75 Watts

Type Motor:

Permanent magnet DC

Type Rotation:

CW, CCW switch controlled

Speeds:

10,15,20 degrees per second

Rotation Tolerance:

Plus or minus 2 percent

Vibrator Frequency:

1550 cycles per minute

Vibrator Amplitude:

.002 to .005 inches

Weight-Net:

100 lbs.

Dimensions:

Height: 29-5/16 inches Max.

Width: 19-3/8 inches Max.

Depth: 17-3/8 inches Max.

Section III. TEST EQUIPMENT, SPECIAL TOOLS AND MATERIALS.

1-6. Special Tools And Equipment. No special 'tools or equipment are used for maintenance of the instrument.

1-7. Consumable Materials. Consumable materials used for maintenance of the instrument are listed in Table 1-1.

Table 1-1. Consumable Materials

Item Number

Nomenclature

Military Specification

Aircraft and Instrument Grease

MIL-G-23827

Dry Cleaning Solvent

P-D-680

Grease, High Vacuum, Silicone

Solder

QQ-S-571

1-1