12.64.8. Briefly explain the effects of weight, IAS, wind, and flap extension on the glideangle.
Weight: – the aircraft weight does not affect the glide angle
IAS: – If the glide speed is higher or lower than recommended the L/D ratio will not be as good and the glide angle will be steeper (diagram)
Wind: The glide angle stays the same regardless of no wind headwind ot tailwind – the glide angle relative to the airmass is the same
Flap extension: The use of flaps reduces the L/D ratio and the glide angle is steeper as a result
12.64.6. Explain how the lift/drag ratio determines a constant speed glide angle.
12.64.4. Explain how the forces in a glide become modified in a constant speed power ondescent.
The glide angle at any given speed in teh glide is directly determined by the lift / drag ratio.
If the L/D ratio is high the glide angle will be shallow
If the L/D ratio is poor the glide angle will be steep
12.64.2. Identify and name the forces acting in a glide.
++ diagram++
– it is assumed that any thrust from the propellor is negligible with the throttle closed,
– weight lift and drag are the remaining forces
– perpendicular component of the weight force is balanced by the lift
– the component of weight parallel to the flightpath is equal and opposite to the drag
12.62.10. Briefly explain the factors which affect climb performance.
Power:
– reducing power decreases climb performance
Airspeed:
– flying faster or slower than the recommended airspeed can degreade the angle and /or rate of climb
Flap extension:
– extended flaps decrease the climb performance due to the indreased drag.
Best climb performance is achieved with flaps up
Weight:
– an increase in weight will degrade climb performance as more power is required. Best climb performance is achieved with lighter aircraft weights
Altitude:
– The decrease in air density as altitude is gained causes a decrease in both engine and airframe performance
Temperature:
– because air density is reduced higher ambient temperatures reduce cllimb performance
Manoevre:
– any manoevring in the clim such as turning will absorb some of the excess power and climb performance will be decreased
Headwind and tailwind:
– These affect the climnb angle over the ground but not the rate of climb
12.62.8. Using a PA/PR (power available/power required) graph, show the derivation ofmaximum rate of climb speed.
++ diagram++
For maximum rate of climb spped – this is the speed at which there is the greatest excess of power available over power required
12.62.6. Define the meaning of Vx (max angle) and Vy (max rate).
12.62.4(c) . cruise climb
12.62.4(b) . maximum rate of climb; Sub Topic Syllabus Item
Maximum angle climb
– best gradient
Maximum rate climb
– best vertical speed
Normal climb
– speed is usually higher than the speed for maximum rate of climb and is a compromise between speed and rate of climb
Vx max angle
Vy max rate