Turning Flashcards
Forces in a level turn
Φ angle between lateral axis and aircraft upgoing wing, this is the vertical component of lift.
Centripetal force is the remains lift force.
Angle Φ is the angle between remaining lift force and vertical force.
Forces in vertical axis - level turn
Vertical component of lift = lift x cosΦ
Lift x cosΦ = weight
Centripetal force = lift x sinΦ
Load factor in a level turn
n=L/W
Weight = lift x cosΦ
So n = 1/cosΦ
Stall speed in a turn
Assuming constant speed, as AOB increases, turn radius reduces.
AOA must increase to produce extra lift
Critical AOA is reached and you stall
Stall speed is a function of weight
Centripetal force
m x v^2 / r
Turn radius
V^2 / g tanΦ
Rate of turn
Number of degrees (expressed in degrees per second) of heading change that an aircraft makes.
Rate 1 - 3 degrees per second, 180 per minute, 360 in 2 mins.
Rate 2 - 6 degrees per second, 360 per minute.
Rate 3 - 9 degrees per second, 360 in 40 seconds.
Rate 1 AOB = (TAS/10) + 7.
Turn rate
Turn radius = V^2 / g tanθ. Ms^-1
Rate of turn = TAS / Radius
Rate of turn is….
Directly proportional to speed..
Inversely proportional to radius of turn..
Rate of turn = TAS / Radius
If TAS doubles
Then TAS x2 / Radius x 4
Climbing turn
Effective AOA higher in outer wing than inner wing.
Outer wing stalls first.
Descending turn
Outer wing travels faster and further.
Inner wing stalls first (higher effective AOA).
Effect of altitude
Higher v^2 (TAS) as you get higher.
So radius of turn increases.
The coordinated turn - right turn
Coordinated - needle right, ball middle
Slipping into the turn - needle right, ball right - too much roll
Skidding out of turn - needle right, ball left - too much rudder
Factors that may affect the the coordination of a turn
Adverse aileron yaw
Engine torque affects
Propeller gyroscopic effect
Spiral slipstream effect
Asymmetric thrust
