Climbing and descending Flashcards
Load factor in level flight
1
What does a head wind effect do to flight path angle
It’s steeper
What does a tailwind do to Flight path angle
Shallower
Underslung engines
Produce a pitching up moment
Best angle of climb
Steepest climb angle
Good for avoiding obstacles
Best rate of climb
If obstacle clearance isn’t an issue, best rate of climb is good for getting to altitude quickly with a lower flight path angle
Flight path angle
angle between the aircraft’s path through the air and the local horizontal.
Gamma
Pitching angle/climb angle
AoA plus flight path angle
Faster speed in climb
AoA reduces so climb angle reduces
Slow speed in a climb
More CL required
AoA increases
Climb angle increases
Lift formula using trig
Lift = WcosY
Angle of climb formula
SinY = T-D/W
Tells us that a steeper climb angle
Thrust must increase
Drag must reduce
A/c must be lighter
Load factor in a climb and descent
CosY
WsinY
Component of weight down the climb
Added with drag shows the amount of thrust required to maintain equilibrium
Speed for best angle of climb - jet
Vx
Depends on the amount of excess thrust - Vmd has the greatest excess thrust with min drag
So vx = vmd
Speed for best angle of climb - propeller
Vmp is vx for a prop
Vx increases for an increase in altitude
Vmp is too slow to fly at
Vmp
Speed for min power
Always 76% of vmd
At the back end of the drag curve which is risky
Power available
Thrust x TAS
Load factor in a steady climb
Less than 1
Rule of thumb for climb gradient
3 degrees = 5% gradient
Gradient formula
T-D/W x 100
Min legal gradient requirement for a twin jet
2.4%
Using the max legal requirement gradient for a jet how can you work out the max weight allowed
W = T-D/2.4 x100
Descent angle Y
Flight path angle (AoA) plus pitch angle (ø)
Excess drag formula in a descent
SinY = D -T/W
In a steady descent
Weight is greater than lift
Drag is greater than thrust
Load factor in a descent
Less than 1
To increase descent angle
Thrust is reduced
Drag will be greater
T = D - WsinY
Steady glide
Component of weight must equal lift
Comment of weight in the direction of the glide path must equal drag
Lf is less than 1
Best glide range
We want the best speed so Vmd is best glide range
Need to be near Vmo
4 degrees AoA
Where is the gradient/ angle of descent the smallest
At the best L/D ratio
Vmd
4 degrees AoA
Glide range formula
Height x L/D ratio
Does changing the AoA increase glide range
No it reduces it
Rate of descent formula
Angle x speed
Also = vmp
Shows that if angle increases speed must decrease
Best glide endurance
Vmp
Increased weight impact on glide range
No effect in still air
Effect of weight/mass on glide endurance
Decrease glide endurance
Effect of a dirty config on glide range
Reduce glide range
Wind impact on endurance and range
Only effects glide range
What is glide endurance all about
Staying airborne for as long as possible
The effect of a lower mass on glide duration
Increases glide duration
