Textbook page 169, 171

The function of the aircraft electrical system is to generate, regulate and distribute electrical power throughout the aircraft.

More and More Electricity

AC (Advisory Circular) B CHAPTER 11. AIRCRAFT ELECTRICAL SYSTEMS SECTION 20. ELECTRICAL AND ELECTRONIC SYMBOLS

Alternating Current

DC Alternators

Electrical Units of Measure Voltage (pressure) unit of measure is the Volt Current (flow) unit of measure is the Ampere (amp) Resistance (friction) unit of measure is the Ohm Power (force) unit of measure is the Watt

Block Diagrams A block diagram is used as an aid for troubleshooting complex electrical and electronic systems. A block diagram consists of individual blocks that represent several components, such as a printed circuit board or some other type of replaceable module.

Pictorial Diagrams In a pictorial diagram, pictures of components are used instead of the conventional electrical symbols found in schematic diagrams. A pictorial diagram helps the maintenance technician visualize the operation of a system.

Schematic Diagrams A schematic diagram is used to illustrate a principle of operation, and therefore does not show parts as they actually appear or function.

Bus In electrical power distribution, a busbar is a strip or bar that conducts electricity within an electrical apparatus. Its main purpose is to conduct electricity, not to function as a structural member. A distribution point in an aircraft electrical system to which the battery and the generator(s) are connected and from which the electrical loads derive their power. In computer architecture, a bus is a subsystem that transfers data between components inside a computer, or between computers The word bus comes from a shortened version of omnibus, the Latin word that roughly means all in one

Switch A device for turning on or off or directing an electric current or for making or breaking a circuit. Textbook page 173

Circuit Breaker An automatic switch that stops the flow of electric current in a suddenly overloaded or otherwise abnormally stressed electric circuit.

Fuse A current limiting device.

Coaxial or Coax Cable The term coaxial comes from the inner conductor and the outer shield sharing a geometric axis. Coaxial cable is used as a transmission line for radio frequency signals. Its applications include feed lines connecting radio transmitters and receivers with their antennas.

Wed 11-28

Coaxial or Coax Cable The inner and outer conductors are separated by an insulating layer known as dielectric. Choice of materials and dimensions determines the cable's electrical properties, including attenuation at various frequencies.

Dielectric The ideal dielectric is air however air would not hold the center conductor in place and that is one of the important requirements of the dielectric. A foam material similar to Styrofoam is used to provide the mechanical properties needed and approximate the electrical properties of air.

Shielding Prevents other signals from entering the cable such as pagers, cell phones, transmitters etc. Prevents leakage of cable signals out of the cable.

Coaxial Cables typically have the following construction: Metallic center conductor Layers of Dielectric or insulating Material A shield Foil Wire mesh A protective jacket

Coax Cable AC 43 Never kink coaxial cable. Never drop anything on coaxial cable. Never step on coaxial cable. Never bend coaxial cable sharply. Never loop coaxial cable tighter than the allowable bend radius. Never pull on coaxial cable except in a straight line.

Coax Bend Radius Textbook page 228

Instruments Required by FAR For VFR flight during the day (1) Airspeed indicator. (2) Altimeter. (3) Magnetic direction indicator. (4) Tachometer for each engine. (5) Oil pressure gauge for each engine using pressure system. (6) Temperature gauge for each liquid-cooled engine. (7) Oil temperature gauge for each air-cooled engine. (8) Manifold pressure gauge for each altitude engine. (9) Fuel gauge indicating the quantity of fuel in each tank. (10) Landing gear position indicator, if the aircraft has a retractable landing gear. Textbook Chapter 21 Installing page 156, 160

Federal Aviation Regulations Emergency locator transmitters ATC transponder and altitude reporting equipment Altitude alerting system or device Traffic alert and collision avoidance system equipment Terrain awareness and warning system Automatic Dependent Surveillance-Broadcast (ADS–B) Out equipment.

ESD Electro Static Discharge

ESD

ESD Packing Material

Voltage– Voltage symbol is traditionally E for ElectroMotive Force (EMF) Current– Current symbol is traditionally I for Intensity Resistance– Resistance symbol is R in equations and the Greek symbol omega Ω for values Power – Power symbol may be Power orWatts

Ohms Law

AC (Advisory Circular) B CHAPTER 11. AIRCRAFT ELECTRICAL SYSTEMS SECTION 20. ELECTRICAL AND ELECTRONIC SYMBOLS