07 Rate of Climb Flashcards
Rate of climb?
Height Gained / Time
Angle of climb x TAS
Rate of Climb in terms of power?
Rate of climb
= (Power avalaible - Power Required) / W
Vy?
Speed for maximum rate of climb.
The speed at which the difference between power avalaible and power requried is the greatest.
How to find Vy for a jet?
Using the power / TAS curve.
A rate of climb is possible at a constant speed wherever there is an excess of power avaliable.
Vy is where there is maximum excess power between the power required and the power avaliable lines.
As altitude rises, what happens to Vy (CAS)?
Reduces but remains higher than Vmd, up to the absolute ceiling when the speeds theoretically coincide.
How to find Vy for a prop?
Found from a Power / TAS curve.
Vy prop occurs at the point of maxiumum excess power, point with the biggest differnece between Power required and power avaliable.
Vy is higher then Vx
When do you use Vx and Vy
Vx - If you need to get over an obstical. This is the speed that offers the greatest climb in the least amount of distance.
Vy and angle of attack?
On a jet, Vy is faster then Vmd meaning AoA is less then 4 degrees.
On a prop, Vy is close to Vmd, indicating AoA is about 4 degrees.
Effect of Mass on Vy?
The total drag curve moves up and right due to increased induced drag.
Therefore rate of climb decreases as there is less excess power and Vy increases.
Effect of config on Vy?
Increase in parasite drag causes the drag curve to move up and to the right.
Therefore rate of climb decreases as there is less excess power and Vy decreases.
Effect of altitude on Vy?
As altitude increases, air density reduces, excess power reduces.
For power against TAS, the drag curve moves up and left with altitude, as density is decresing, hence parasite drag is decreasing.
Vy increases.
Effect of altitude on Vy?
TAS and IAS comparison
TAS
* Excess power and rate of climb reduce.
* Vy (TAS) increases slightly.
IAS
* Excess power and rate of climb reduces
* Vy(IAS) reduces,
Effect of temperature on Vy?
On hot days, rate of climb decreases and Vy increases, due to reduced thrust and parasite drag.
Effect of an engine failure on Vy for a jet?
Engine failure halves the power avaliable.
Increase in parasite drag causes the drag/power curve to move up and left.
**The reduction in excess power is considerable and the optimum rate of climb speed, Vy is slower then for all engines. **
Effect of an engine failure on Vy for a prop?
Engine failure halves the power avaliable.
Increase in parasite drag causes the drag/power curve to move up and left.
**The reduction in excess power is considerable and the optimum rate of climb speed, Vyse is slower then for all engines. **
