Power, Vx & Vy, Aerodrome Distances (15-05-18) Flashcards
What is the equation for power required?
Power required = Drag x TAS
What does a tangent to the power required curve through the origin show?
VMD
What can be seen from the power mega graph?
Max speed jet
Max speed prop
Vy jet
Vy prop
VMP (speed of max endurance prop)
VMP (speed of max range prop)
What is VY and when does it occur?
The speed for best rate of climb and it occurs when the amount of excess power available is biggest.
What determines the ROC in terms of power?
The size of the gap between power required and power available.
What speed in relation to VY does a jet need to fly to gain it’s benefit?
Within 10%, but it is rarely used IRL.
What speed does VY occur at for a prop?
VMP
What is best endurance speed sometimes referred to as?
Holding speed.
Out of Vx and Vy, what will achieve the higher altitude for a given horizontal distance?
Vx
Out of Vx and Vy, what will achieve the higher altitude for a given amount of time from TO?
Vy
When flying for fuel efficiency what speed is preferred out of Vx and Vy and why?
Vy because at high altitude fuel flow is low so you want to get high ASAP.
Why does fuel flow reduce with altitude?
For peak efficiency a certain fuel to air ratio is desired so with there being less air at altitude, there must also be less fuel flow.
What happens to rate of climb and angle of climb with an increase in altitude, mass or flap?
They decrease.
What happens to Vx and Vy with an increase in altitude at constant IAS?
Vx is unaffected
Vy gets slower
What happens to Vx and Vy with an increase in altitude at constant TAS?
Vx increase
Vy increases
What happens to Vx and Vy with an increase in mass?
Vx increases
Vy increases
What happens to Vx and Vy with an increase in flap?
Vx gets slower
Vy gets slower
What is the technique for accelerating or decelerating in a climb?
Changing pitch
lower pitch to accelerate
increase pitch to decelerate
If you start to accelerate in a climb what happens to rate of climb and angle of climb?
Thrust isn’t changed so angle of climb lessens and rate of climb reduces
If you start to decelerate in a climb what happens to rate of climb and angle of climb?
Angle of climb increases but rate of climb reduces
What happens to rate of climb after an acceleration in a climb?
It increases
What talking about engine failures in an exam what should be assumed if not otherwise stated?
It is a twin prop aircraft
What is the main source of parasite drag after an engine failure?
Rudder deflection
What is the relationship between Vx and Vxse for jet and prop aircraft?
Jet
Vx > Vxse
Prop
Vx < Vxse
What is the relationship between Vy and Vyse for jet and prop aircraft?
Jet
Vy > Vyse
Prop
Vy > Vyse
What is the approximate value of AoA at VMD?
4 deg
What do points 1, 2, 3 and 4 correlate to on the following diagram?
1 - Minimum CD
2 - CL/CDmin, VMD
3 - VMP
4 - CLMAX
What is Landing distance available (LDA)?
The distance between thresholds
What is Take off run available?
The paved surface that can be used during the TO run
LDA plus any starting extension
What is the stopway?
A part of the runway that can be used to stop the aircraft in case of an emergency
What is the Accelerated stop distance available?
TORA + stopway
Total length of runway that can be used to accelerate or stop the aircraft
What is the Runway End Safety Area (RESA)?
A relatively safe ground section just in case the runway is over run
What is the clearway?
The area an aircraft can use between lift off and screen height.
It must be at least 75m either side of the centre line with total width being 152m.
clearway maximum length is 50% of TORA
Maximum up slope of the clearway is 1.25%
What must objects in the clearway be?
Frangible (break on impact)
What is the Take Off Distance Available (TODA)?
TORA + clearway
Can contain aircraft from brake release to screen height
maximum length is 150% of TORA
Are stop ways, clear ways and RESAs optional or mandatory?
Stop ways and clear ways are optional
RESAs are mandatory
What defines a balanced runway and what advantages and disadvantages does it come with?
TODA = ASDA
Saves time and adds a degree of safety but we can take less weight.
Why must we account for a small loss of runway for TO?
When lining up on the runway we follow a small arc which eats into a small portion of runway.
What decreases actual TORA/TODA?
line up on runway
intersection further along the runway
