Aircraft Electrics and Avionics

Aims and objectives

• describe fundamental aircraft electrical and avionic systems and conduct analysis of the same, 
• describe the integration of such systems and the ground systems with which some aircraft navigation systems interact,
• discuss with aviation specialists in avionics and electrical systems the importance of these systems in specific airline operations.

Teaching methods

Assessment

Generic skills outcomes

• analysis skills,
• problem solving skills,
• ability to tackle unfamiliar problems, and
• ability to work independently.

Content

• Acronyms, Simple aircraft ac and dc schematic circuits that employ parallel and series switching and relay functions (e.g. Engine Fuel Boost Pumps and Engine Fuel Shut-Off Valves (EFSOV)).

• Wire type selection, insulation types, shielded and twisted cables, installation & routing, identification. Differences between aircraft wiring diagram types (Wiring Diagrams and Schematic Wiring Diagrams) and their uses. 

• Static Electricity its generation and its safe discharge- its effects on radio and navigation systems. Aircraft bonding methods for ac and dc circuit current return paths.

• AND, OR, NAND, NOR logic gates, Diodes and their applications to aircraft circuits and system operation, Relays. 

• Three phase ac split generator systems (twin engine aircraft). A/C generators, frequency selection (Why 400 Hz not 50Hz?); Three phase generator systems in parallel arrangements (multi engine aircraft). Generator output current demands, Generator and Bus priority with system failures. The generation of dc by Transformer Rectifier Units, Nickel Cadmium batteries, battery chargers, APU generator and external power supplies.

• Circuit breakers and circuit protection.

• Thermocouple systems (reciprocating and gas turbine engines), turbine EGT systems.

• Fire Warning and Detection, its interface with EFSOV and Generator system, Landing Gear position, Take-Off and Engine Vibration.

• Wave modulation, HF frequency range and propagation, HF limitations, VHF frequency range, VHF limitations, the correct use of HF and VHF systems,  

• Practical uses of ACARS – its interface with communications systems; Practical uses of ACARS –Flight Crew monitoring - Out, Off, On, In (OOOIs), Flight "snapshots" – Climb, Cruise, Descent, the ACARS ground links to Airline Maintenance and Flight Operation centres, its interface with the DFDR for Engine Trend monitoring (Vibration or EGT).

• History and development, method of recording, rate and duration, CVR/DFDR,.

• VHF NAV (VOR / ILS / MKR), ADF and DME, ATC systems and Transponder operation (the short Range Area Navigation (RNAV) systems), Radar (X Band), Parabolic versus Phased Array antennas, Forward Looking Weather Radar (FLWR) systems, FLWR’s windshear detection capability, three dimensional Weather Radar systems.

• LRRA systems (operation and influence of external factors), GPWS (modes and operation), and Enhanced Ground Proximity Warning Systems (EGPWS). Its windshear detection method.

• Need for TCAS, its interface with other A/C systems, A/C detection methods, Priority of TCAS calls versus GPWS, Stall Warning and Windshear.

• Mechanical Gyro systems versus the Ring Laser Gyro (RLG), the RLG in Inertial Reference Units (IRUs), Inertial Reference Systems (IRS)

• Global Navigation Satellite Systems (GNSS),RAIMS warnings; GNSS’s interface with A/C systems and Ground Based Augmentation Systems (GBAS) and Global-based Regional Augmentation Systems (GRAS) assisting precision Global Positioning Landing (GPL) systems. Automatic Dependent Surveillance Broadcast (ADS-B) that provides enroute ATC surveillance. Long Range RNAV systems, using Required Navigation Performance (RNP) and Actual Navigation Performance (ANP) for three dimensional landing guidance and Reduce Vertical Separation Minimums (RVSM).