AM.II.H.K7

From the FAA library

• Aviation Maintenance Technician Handbook - Airframep. 10-50
  Chapter 10: Aircraft Systems › Sources of Power for Gyroscopic Instruments › Pressure-Driven Gyroscopic Instrument Systems

  Figure 10-91. A typical pump-driven vacuum system for powering gyroscopic instruments. A schematic of this twin-engine aircraft vacuum system is shown in Figure 10-92. Note the following components: two engine-driven pumps, two vacuum relief valves ... individual instrument filters. A drain line may also be installed at the low point in the system. Pressure-Driven Gyroscopic Instrument Systems Gyroscopic instruments are finely balanced devices with jeweled bearings that must be kept clean to perform properly. When…

• Aviation Maintenance Technician Handbook - Airframep. 10-50
  Chapter 10: Aircraft Systems › Sources of Power for Gyroscopic Instruments › Electrically-Driven Gyroscopic Instrument Systems

  pressure gyro system. Figure 10-92. An example of a twin-engine instrument vacuum system. Electrically-Driven Gyroscopic Instrument Systems A spinning motor armature can act as a gyroscope. This is the basis for electrically driven gyroscopic instruments in which…

• Aviation Maintenance Technician Handbook - Airframep. 10-45
  Chapter 10: Aircraft Systems › Sources of Power for Gyroscopic Instruments

  Sources of Power for Gyroscopic Instruments Gyroscopic instruments are essential instruments used on all aircraft. They provide the pilot with critical attitude and directional information and are particularly important while flying under IFR. The sources of power for these instruments ... vary. The main requirement is to spin the gyroscopes at a high rate of speed. Originally, gyroscopic instruments were strictly vacuum driven. A vacuum source pulled air across the gyro inside the instruments to make the gyros spin. Later, electricity…