Thrust, Drag, Power (14-05-18) Flashcards
How does humidity affect density?
More humid is less dense due to water molecules being lighter than nitrogen/oxygen.
Regarding C T M, what happens in an inversion and an isotherm?
In an inversion M and T switch, and in an isotherm, M and T are parallel
How do we measure jet thrust?
With the engine pressure ratio which is the ratio between turbine outlet pressure and compresser inlet pressure
or
N1, which is the RPM as a percentage of theoretical maximum
What happens to fuel flow at high altitude?
it reduces
What must we do to fuel flow to remain at peak efficiency when fly from warm to cold air?
We must increase fuel flow
If we want to remain at constant speed, what must we do to fuel flow when flying from warm to cold air?
We must reduce fuel flow.
What are the speed neutral speeds for prop and jet with and without flaps?
They are all at Vmd:
Type Clean Flaps
Jet 1.6Vs 1.4Vs
Prop 1.3Vs 1.2Vs
What is typical approach speed?
1.3Vs
What can be seen from the Thrust mega graph?
Max speed jet
Max speed prop
VMD (speed max endurance jet)
1.32VMD (speed max range jet)
Vx Jet
Vx prop
Where does Vx occur?
Where the gap between thrust required and thrust available is greatest.
What does angle of climb depend on?
The amount of excess thrust available
What does jet endurance depend on and at what speed does max endurance occur?
Fuel quantity and fuel flow
Vmd.
What does jet range depend on and at what speed does max jet range occur?
Fuel flow and forward airspeed
1.32Vmd
What is the equation for power?
Power = thrust x TAS
What is the most important variable for aircraft performance for jets and props?
Jets - Thrust
Props - Power
