aerodynamic theory review 1 atc chapter 6. aim to review climbing and descending
TRANSCRIPT
Aerodynamic Theory Review 1ATC Chapter 6
Aim
To review climbing and descending
Objectives1.State the forces in a climb2.Define rate and angle of climb3.State the forces in a descent4.Define rate and angle of descent
R.A.F
W
DT
L
What are the four forces acting on our aircraft in straight and level?
1. Forces in a climb
R.A.F
W
DT
L
PCW
RCW
RCW
We can see weight is acting at an angle to all the other forces so we can break it up into a Perpendicular Component of Weight and a Reward component of weight
1. Forces in a climb
R.A.F
W
DT
L
PCW
RCW
RCW
We can now resolve the force vectorsIs the aircraft in equilibrium?
R2
R1
1. Forces in a climb
R.A.F
W
DT
L
PCW
RCW
RCW
We must increase the power to overcome the RCW
R2
R1 R1
T
The aircraft is now in equilibrium
1. Forces in a climb
R.A.F
W
D
L
PCW
RCW
RCW
R2
R1 R1
T
In Summary:
R1 = R2L < WT = RCW + D
The aircraft is in equilibrium
1. Forces in a climb
We can describe climb performance as either Rate of Climb or Angle of Climb
Rate of climb is the altitude gained over time. Expressed in feet per minute (fpm).
2. Rate and angle of climb
Altitude
Time
We can describe climb performance as either Rate of Climb or Angle of Climb
Rate of climb is the altitude gained over time. Expressed in feet per minute (fpm).
2. Rate and angle of climb
Altitude
Distance
Angle of Climb
Angle of climb is the altitude gained over distance. Expressed as an angle
Definition of Power
Work = Force x Distance
WorkTime
Power =
Force x Dist.TimePower =
2. Rate and angle of climb
Power is supplied by the engine and can be described as the amount of work that can be done in a given amount of time
Thrust is the force applied to the Airflow by the propellerAs we increase speed less thrust will be imparted on the airflow Thrust is limited by the Power Available
Definition of Thrust
2. Rate and angle of climb
Maximum altitude gain over a given time. Achieved by flying at best RoC speed also known as Vy.For the C172SP Vy is 74 KIAS at Sea LevelOur best Rate of Climb (VY) occurs at the point of Max Excess Power
2. Rate and angle of climbBest Rate of Climb
Pa-PrWRoC = 33000 x
Maximum altitude gain over a given distance. Achieved by flying at best AoC speed, Vx.For the C172SP Vx is 62 KIAS at Sea LevelBest Angle of Climb occurs at Max Excess Thrust
2. Rate and angle of climbBest Angle of Climb
Thrust - DragW
AoC = Sin x
Comparison of altitude and distance gained over the same time period at Vx and Vy.
2. Rate and angle of climb
R.A.FW
L
D
What are the forces acting on our aircraft in S&L?
3. Forces in a descent
R.A.FW
L
D
FCW
FCW
PCW
Again we can see weight is acting at an angle to our other forces so we can break it up
3. Forces in a descent
R.A.F
W
L
D
FCW
FCW
PCW
We can now resolve the forces
R
The aircraft is now in equilibrium
3. Forces in a descent
R.A.F
W
L
D
FCW
FCW
PCW
R
In Summary:L < WR = WD = FCW
3. Forces in a descent
The aircraft is now in equilibrium
Like a climb we can describe descent performance as either Rate of Descent or Angle of Descent
Rate of descent is the lost gained over time, expressed in feet per minute (fpm).
4. Rate and angle of climb
Altitude
Time
Like a climb we can describe descent performance as either Rate of Descent or Angle of Descent
Rate of descent is the lost gained over time, expressed in feet per minute (fpm).
4. Rate and angle of climb
Angle of climb is the altitude gained over distance. Expressed as an angle
Altitude
Distance
Angle of Descent
Questions?