Gliding Angle:- Angle which flight path of the Aircraft makes with the Horizontal plane.
Gliding Range: – is the Distance traveled over the ground while Gliding.
Gliding Endurance: – Time taken by the Aircraft to descent to the ground while Gliding.
Gliding Angle depends upon Lift / Drag Ratio.
:: If L/D Ratio is high Gliding Angle will be shallow, or flat.
:: If L/D Ratio is low Gliding Angle will be steep.
For farthest Glide through still air, the Aircraft should be flown at an Angle of Attack & the Airspeed that gives the best Lift / Drag Ratio (Usually 4°)
Smaller flaps setting increase Lift significantly with only a small increase in Drag. Low flaps settings are also known as LIFT FLAPS, therefore Range increases.
Whereas large flaps setting increase Drag significantly with only a small increase in Lift. High flaps settings are also known as DRAG FLAPS, therefore large flap settings will give much steeper glide and decreases Range.
:: Flaps steeper the Glide
:: Weight increases best Lift / Drag Ratio, therefore also requires Aircraft speed to increase.
:: Gliding Range is not affected by changing Weight.
Gliding angle is also not affected by changing Weight provided the best Lift / Drag Ratio speed is maintained, Which varies with changing Weight.
With increase in the Weight Gliding Endurance decreases or Rate of Descent increases.
The change in the Temperature does not affect the glide as the Engine Power is not available.
Although in very high temperature the Air Density will be less, which will affect the Lift by the surrounding air to the airfoil.
Altitude:–Aircraft flying at a higher altitude will have a higher Gliding Range due to higher TAS at higher altitude. Gliding Angle and Gliding Endurance Time taken to descend is not effected by change in the altitude.
GLIDING ANGLE: Angle of Flight Path with the Horizontal plane
GLIDING RANGE: Distance traveled forward by the Aircraft during gliding
GLIDING ENDURANCE: Time taken by the Aircraft during descending
:: Gliding angle is shallow if L/D ratio is high, and Aircraft descends slowly.
:: Gliding angle is steep if L/D ratio is low and Aircraft descends fast.
:: Weight of the Aircraft affects Induced Drag
If Weight increases, lift requirement increases and therefore Induced Drag increases.
Therefore for every different Weight of the Aircraft L/D Ratio also changes.
Factors affecting Glide-
- Airspeed – Gliding angle depend upon L/D ratio. L/D ratio depends upon angle of attack and angle of attack depends upon airspeed.
Therefore L/D ratio depends upon airspeed or gliding angle depends upon airspeed.
For a particular weight of Aircraft there is only one airspeed, which will give the best gliding angle.
Therefore, it you fly at any other speed higher or lower than the given speed for a give best L/D ratio speed, then L/D ratio speed will decrease and gliding angle will increase. Because any other speed will cause a increase in drag.
At speed lower than best L/D ratio speed, the Induced Drag increases.
At speed higher than best L/D ratio speed Profile drag increases.
Gliding Endurance- time taken by Aircraft to glide down to the Earth.
Gliding Range- Horizontal distance, traveled by Aircraft while gliding.
- Weight – Change in weight will not affect the gliding angle provided the best L/D ratio speed is adjusted.
If weight increases, you require higher gliding speed.
A 10% increase in weight requires 5% increase in gliding speed.
Weight increases gliding range remains same, but gliding endurance decreases Or ROD/Rate of glide increases.
- Temperature has No effect
Because No engine power.
- Wind velocity does not affect Gliding Angle.
Wind velocity affects Apparent Gliding Angle.
Head wind increases Apparent Gliding Angle.
Tail wind decreases Apparent Gliding Angle.
Wind velocity affects Gliding Range.
Head wind decreases Gliding Range.
Tail wind increases Gliding Range.
Wind velocity does not affect Gliding Endurance
ROD upwind or downwind remains the same.
- Flaps – Flaps increases gliding angle because they decrease L/D ratio.
- Power – Effect of Power on Glide.
During glide if Power increases Gliding Angle decreases, Range increases, Endurance increases.
In a power ON Glide, Thrust is less than Drag that is why it is Gliding.