44 Questions
What is the primary function of the engine control system in a gas turbine engine?
To control the flow of fuel and air to the engine
What is the main component of a gas turbine engine responsible for compressing air?
Compressor
What type of aircraft engine is characterized by a large fan at the front that accelerates a significant amount of air?
Turbofan
What is the purpose of the maximum fuel limit in a gas turbine engine?
To protect against combustor blow-out and surge/stall
What is the primary function of the fuel flow control system in a gas turbine engine?
To regulate the fuel flow into the combustor
What is the purpose of the turbine blade temperature limit in a gas turbine engine?
To prevent overheating
What is the primary function of the intake case in a gas turbine engine?
To direct air into the compressor
What is the purpose of the operational limits in a gas turbine engine?
To ensure safe operation within established limits
What is the primary purpose of the fuel tanks and aircraft fuel pumps in an aircraft?
To supply fuel to the engines and auxiliary power unit
What is the function of the Low Pressure Fuel Valve in the fuel tank?
To halt fuel flow in case of emergency
What is FADEC in the context of aircraft engines?
Full Authority Digital Engine Control
What is the primary function of the Engine Throttle Lever in the cockpit?
To control engine thrust
What is the purpose of the Cockpit Indication system?
To display engine parameters and warning messages
What is one of the key drivers of the design of an engine control system?
All of the above
What is one of the environmental considerations in engine design?
All of the above
What is the effect of increasing fuel pressure on the engine?
Increases gas temperature, resulting in higher engine speed
What is despatchability in the context of aircraft operation?
The ability of an aircraft to depart on schedule
What is the purpose of the variable inlet guide vanes (VIGVs) or variable stator vanes (VSVs)?
To maintain a safe margin from the engine surge line
What is the purpose of qualification testing in engine control system design?
To demonstrate compliance with regulatory requirements
What is the primary function of the Fuel Control Unit (FCU) or Fuel Management Unit (FMU)?
To maintain conditions demanded by the pilot
What is the benefit of advanced diagnostic and prognostic capabilities in engine control systems?
All of the above
What is the difference between VIGVs and VSVs?
VIGVs are used on smaller engines, while VSVs are used on larger engines
What is the purpose of the pneumatic capsules in the FCU/FMU?
To modify flows according to prevailing atmospheric conditions
What is the main advantage of the FADEC system?
It allows for more efficient engine operation
What is the purpose of the dashpot/spring/damper combinations in the FCU/FMU?
To control the acceleration and deceleration rates
What is the effect of changes in altitude, air temperature, and aircraft speed on the engine?
It changes the density of the air at the engine intake
What is the primary difference between a Hydro-mechanical system and a FADEC system?
The level of automation in FADEC systems
What is the purpose of the Health Status Annunciator (HSA) in a FADEC system?
To display fault reports to the flight and maintenance crew
What is the benefit of using a FADEC system in terms of reliability?
A 54% increase in MTBF
What is the function of the Fuel Flow Regulator (FFR) in a FADEC system?
To regulate fuel flow
What is the advantage of FADEC systems in terms of weight?
A 62% decrease in weight
What is the purpose of the Master Power Control Units (MPC-1 and MPC-2) in a FADEC system?
To control all aspects of the aircraft engine
What is the full form of FADEC?
Full Authority Digital Engine Control
What is the benefit of using a FADEC system in terms of cost?
A 63% decrease in cost
What input variables does the FADEC system receive to determine the current flight condition?
Air density, throttle lever position, engine temperatures, engine pressures, and others
What is the primary purpose of the FADEC system?
To provide optimum engine efficiency for a given flight condition
What is the function of the EEC in the FADEC system?
It is the core of the FADEC system
What type of sensors are used to measure engine speed?
Pulse probes
What is the function of the FADEC system's power command?
To control engine actuators
What is the purpose of the FADEC system's adaptive control?
To automatically take necessary measures to avoid exceeding engine limitations
What is used to measure total temperature in the FADEC system?
Temperature probe
What is the function of the FADEC system's engine health monitoring?
To provide engine health and maintenance reports
What is used to measure fuel flow in the FADEC system?
Turbine flow meter
What is the function of the FADEC system's prognostic?
To predict engine maintenance requirements
Study Notes
Aircraft Engine Control System
Engine Control System Overview
- The engine control system manages the flow of fuel and air to the engine
- The system has to control the goals and objectives of engine and aircraft design
- It also handles the increasing complexity of modern engines
- Functions include:
- Varying aerodynamic and geometry of the engine
- Managing faults and monitoring engine health
- Engine protection
- Controlling cabin bleeds and power off-takes
Components of a Gas Turbine Engine
- Combustion chamber
- Compressor
- Intake case
- Turbine
- Nozzle
Types of Aircraft Engines
- Turbojet
- Turboprop
- Turbofan
- Turboshaft
Operational Limits
- Structural limits:
- Maximum fan and core speeds (N1 and N2)
- Maximum turbine blade temperature
- Safety limits:
- Adequate stall margin (compressor and fan)
- Lean burner blow out (minimum fuel)
- Operational limit:
- Maximum turbine inlet temperature
- To provide long life for the engine
Fuel Flow Control
- Power or thrust can be controlled by regulating the fuel flow into the combustor
- When higher thrust is required, throttle is opened and fuel pressure to the burner increases
- Fuel control unit (FCU) or fuel management unit (FMU) is used to maintain conditions demanded by the pilot
Air Flow Control
- To ensure efficient operation over a wide range of environmental conditions
- Can be controlled through variable inlet guide vanes (VIGVs) or variable stator vanes (VSVs)
- VIGVs affect airflow at the inlet of the compressor
- VSVs vary airflow within the compressor
FADEC System Overview
- Full Authority Digital Engine Control system
- Autonomous control of the engine throughout its whole operating range
- Comprises Electric Engine Control (EEC) and other accessories
- Components include:
- Master Power Control Units
- Sensors for manifold temperature and pressure
- Cylinder Head Temperature (CHT) sensor
- Exhaust Gas Temperature (EGT) sensor
- Speed sensors
- Fuel pressure sensors
- Low voltage harness
- High voltage harness
- Throttle body assembly
- Health Status Annunciator (HSA)
- Fuel injection system
How FADEC Works
- Receives multiple input variables of the current flight condition
- Computes engine operating parameters such as fuel flow, stator vane position, and bleed valve position
- Provides optimum engine efficiency for a given flight condition
- Allows manufacturers to program engine limitations and receive engine health and maintenance reports
Data and Sensors
- Sensors located within the gas turbine engine
- Signals and sensors include:
- Throttle position
- Air data (altitude and airspeed)
- Total temperature
- Engine speed
- Engine temperature
- Pressure ratio
- Nozzle position
- Fuel flow
- Fuel flow control
- Air flow control
This quiz covers the overview of aircraft engine control systems, including their functions, goals, and objectives. It also explores the components and features of modern engine control systems.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
