Atp Flashcards
Mach number
Ratio of TAS to the speed of sound
Taf TEMPO
Notable conditions but expected to last less than an hour
Greater than 50% chance of happening
How many times a day does a taf cone out?
4 times 0z 06z 12z 18z
What stage of a ts is a microburst in?
Mature
Basics of jet engine operation
Intake
Compression
Combustion
Exhaust
Inverter
Converts DC to AC for use by instrumnents and avionics
Hot start
Too much fuel too early in the start process before enough air is conpressed. Interstage turbine temp exceeds manufactures prescribes starting limits
Hung start
Light off occurs but the engine fails to reach idle RPM. EGT rises but RPM will hang. High altitide or hot, low density air
Bleed air
Used for oressurization of the canin
Must be colled first by onvoard refriferation system
Pressurization, heating, deicing/anti-icing, pneumatic engine starting
What is an accumulator?
A steel cylinder with a diagram in yhe middle. One half is fikled with nitrogen/air amd the otyer contains fluid. Tge purpkse is to store power.
Thrust reversers
Most are capable of producing 45% of rated engine thrust in reverse direction. This adds 20% braking capability
What is a difusser?
It directs air from the impeller to the manifold. Provides the combistion chamber with air at the correct belocity and pressure for max efficiency
N1/N2
N1 speed of low pressure compressor/turbine spool
N2 speed of hogh pressure compressor and turbine spool
Turbo fan
Modification of turbo jet engine
Higher thrust/less noise
Large air intakes
Compresor blades ahead of conpressor direct air backward party to compressor and partly through dicts tgat bypass the conpressor and flow between the outside of engine.
Compressors
Supply compressed air to the burners
Increases the pressure of the mass of air that is channeled through the air inlet amd routes it to the burners
- as air is compressed it is heated - may reach 600f before combistion section
Turnine engine components
Air inlet Conpressor Combistion section Turbine Exhaust Accesory section
Stator
Row of non moving vanes attached to the inside of the conpresor case
Fit anugly next to rotors. Move incoming air
Axial flow
Compresses air through a linear series of rotating and fixed blades
Avouds energy loss as a result changing directions. Airflow is parallel to the plane of rotation
Compressor stalls
Compressor blades are actially small airfoils functuoning the same as a propeller or wing
Occurs when tge air mass traveling through the compressor slows down or stops.
First sign: low pulsating sound
Left long enough will result in the sound of a loud backfire
Severe stalls know as hung stalls will dramatically degrade engine output and might result in damage/engine failure
Combistion chanbers
Raises the temperature of the compressed air that passes through and releases the potential energy in the fuel/air mixture. Most of the energy released turns the turbine wheel which is connected to a long shaft to the compressor.
The energy that remains after turning the turbine becomes a high velocity stream of hot gases that exit the exhaust providing forward thrust.
Temp of air leaving compressor 600f
After leaving combustion chamber 1600f
Turbines
Purpose is to convert the energy of combustion chamber exhaust gases into mechanical energy to operate tge compressor and other accesories.
Ongoing concern on flight deck is thetemp if turbine
ITT Interstage Turbine temperature probe
Exhaust section
Located directly behind tge rurbine section
Produces exhaust gas with a high velocity and minimizes exhaust gas turbukence
Exhaust cone and nozzle
- channels all exhaust gases as tgey are discharged from the turbine blades amd combines them into a single cohesive stream
Swept wings
Lets the aircraft go faster by delaying the onset of the airfoils critical mach by allowing the relative airflow over its surface to move outward towards the wingtips so the air encounters less camber and does not accelerate as quickly over the top of the wing. Allows aircraft to reach a higher airspeed before critical mach is reached.
