A light aircraft will descend faster, so will a heavy one..

[JABBARA]

“If you can’t explain it to a six-year-old, then you don’t understand it yourself” Albert Einstein

Following figure is extracted from AIRBUS Getting the Grips with Aircraft Performance P 163 (attached note boxes are mine)

Commented as:

1. For different weights, if respective Green Dot (GD) speed is maintained, Descent Angle (DA, in another word Glide Path Angle, GPA,) and Descent Range remains same; however with increasing weight, Rate of Descent (RD) increases or vice versa

2. For all different weights, if a fixed (same) speed value, within Standard Descent Speed Range (eg 280K), is maintained, as weight increases, DA (=GPA) and RD decreases, consequently Descent Range increases

3. A counter-intuitive point: Why DA (=GPA) decreases with increasing weight?
ANSWER: During glide, the drag along flight path is balanced with the component of weight along flight path, in the opposite direction with drag. Therefore, as weight increases, less GPA (=DA) becomes enough to counter drag; result is less RD

Full stop

NOTE I have a thread titled "AMC3 CAT.OP.MPA.182 Fuel/energy scheme — aerodrome selection policy — aeroplanes" I need some comments and replies please

Thanks

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