AIRCRAFT INSTRUMENT SYSTEMS I

Content

Weeks	Topics
1. Weeks	Aircraft Indicating Systems – General: Variable resistance systems, DC Selsyn systems, synchros (direct torque systems, control transformer, differential synchro), resolvers, LVDT’s, RVDT’s, servo systems and servo loops.
2. Weeks	Pressure Measurement Principles and Instruments: Pressure definitions and their measurement: absolute, gauge and differential pressure; Mechanical sensors and systems: diaphragms, pressure capsules, aneroid capsules, bourdon tubes, bellows; Electrical sensors and systems: strain gauges, piezo-resistive sensors, variable frequency generating system with a capacitance.
3. Weeks	Temperature Measurement Principles and Instruments: Non-electrical temperature measurements: liquid expansion, gas pressure, bimetal strip; Electrical temperature measurement: PTC and NTC temperature dependent resistors, temperature sensing bulb, ratiometer circuits, Wheatstone Bridge circuits, thermocouples, CHT and EGT measurement.
4. Weeks	Fuel Quantity Indication Systems: Mechanical indicators: direct reading tubes, float and magnet; DC electrical indicators: float and ratiometer, magnetic float and reed switches; Capacitive indicators: capacitance, dielectricity, reactance, measuring circuits, calibration for temperature and dielectricity changes; Digital fuel quantity indicating system; Analogue and digital cockpit indications (circuits and displays); Fuel Flow Indication Systems: Transmitters types: vane, turbine, impeller, differential pressure; Safety and CDL requirements. Angle of Attack and Stall Warning Systems: Angle of attack (AOA) definition; AOA sensing and indications: vane and pressure probe type sensors, cockpit indications; AOA effect on stall condition; Stall warning systems: buzzer (reed), vane and micro-switch, stall strip. Engine Vibration Measurement: Principle of operation, cockpit indication.
5. Weeks	Gyroscopic Instruments: Rigidity, precession, degrees of freedom; Basic gyro elements: rotor and gimbals; Electrical and air driven rotors; Gyro types: vertical gyro, directional gyro, rate gyro, rate integrating gyro; Apparent drift and topple.
6. Weeks	Attitude Indicator (Artificial Horizon): Description, use and operating principles of the instrument; Rotor, gimbals, horizon bar, indicator, pitch and roll indication; Gyro erection: with balls, pendulous vanes, levelling switches and torque motors; Remote Artificial Horizon; Acceleration and turning errors.
7. Weeks	Directional Gyro: Description, use and operating principles of the instrument; Rotor, gimbals, horizon bar, indicator, old style (compass type) and vertical card heading indication; Slaving of directional gyro (automatic and manual) ; Gyro Wander: Real wander, apparent wander, correction with latitude nut, transport drift.
8. Weeks	Rate Gyro: Description, use and principles of operation; Rotor and gimbal; Turn and slip indication. Turn Coordinator Indicator: Description, use and principles of operation; Turn coordination indication, Gyro Powering Systems: Electric motors, pneumatic systems, comparison of electrical and air driven gyros (advantages and disadvantages). Magnetic Compass: General magnetism concepts: source of magnetism, magnetic forces and moments; Earth’s magnetic field: poles, inclination, variation.
9. Weeks	Magnetic Compass: Aircraft magnetism: source of magnetism on an aircraft, hard iron magnetism, soft iron magnetism, components of aircraft magnetism, compass deviation and its compensation, EASA limits, compass swing; Direct reading compass: general description and principle of operation, compass requirements, elements, pre-flight checks; Acceleration and turning errors, other errors (index, one cycle, two cycle).
10. Weeks	Gyro Compass (Slaved Gyro): Flux valve, slaving gyro, light aircraft compass systems, MD-80 compass system, manual synchronization, remote compensator, new technology.
11. Weeks	Gyro Compass (Slaved Gyro): Flux valve, slaving gyro, light aircraft compass systems, MD-80 compass system, manual synchronization, remote compensator, new technology.
12. Weeks	Practical Application at Hangar: General safety precautions for working in a hangar and/or workshop; Safety precautions and principles of removing, disassembling, re-assembling, maintenance and installation of aircraft instruments; Introducing instruments and electric-electronic equipments on the aircraft.
13. Weeks	Practical Application at Hangar: Carrying out, helping or observing the removing, disassembling, re-assembling, maintenance, calibration and/or installation of at least one of the physical quantity (pressure, temperature, fuel quantity, rpm, etc.) indicators and one of the gyroscopic aircraft instruments.
14. Weeks	Practical Application at Hangar: Carrying out, helping or observing the removing, disassembling, re-assembling, maintenance, calibration, installation or compass swing procedure of a direct reading compass or gyro-compass.