why do as airplane weight increases the glide ability increases?

Question

in compare a light airplane with a heavier like a cessna 172 with an airbus the larger and heavier has a better glide even an airbus with a higher gross weight has much greater glide than an airbus with a lighter weight according to POH of airplane how is it possible?

Answer 1

AS weight increases, the :"best glide speed" increases.
a lightly loaded C172';s best glide is different than if at gross weight. The distance over the ground will be shorter at gross weight.

Answer 2

Yes you may be right. Sometimes an aircraft may glide farther when it is heavier as compared to when its weight is lower. It seems rather strange but those high performance gliders that are used in competitions, usually have a provision for filling them up with water. The purpose is to increase their weight which in turn improves glide performance and range. But I do not know exactly why this happens. Perhaps it allows them to glide at a higher speed which extends their range.

Answer 3

You are looking at two different wing shapes and failing to provide information that can't be looked up on line as the POH (Pilots Operating Handbook) isn't there.
The 172 is a straight thick wing on a plane designed for efficient safe operation at a relatively low speed. It has about a 12:1 glide ratio.
The Airbus statistics I can find, load not specified, say 16-18:1, for a swept wing, higher speed, load carrying aircraft, built to operate at higher altitudes. The glide ratio is discussed in several places as being typical for airliners.
If you are talking about different models of the Airbus, you should have specified that. A plane designed primarily for long distance flight should have a higher glide ratio for better cruising than a plane designed for getting heavy loads (for its size) for shorter distances being designed with maximum lift for getting up to flight altitude as quickly as possible.

Answer 4

It is important to note that weight is not a factor in the Lift,Drag equation. Therefore, it is not a factor in how far an aircraft can glide. An aircraft always achieves maximum glide at a certain angle of attack.
When gliding for maximum range we must always operate at the optimum angle of attack which produces the maximum Lift,Drag ratio. Therefore the heavier aircraft will have to fly at a higher speed, while the lighter aircraft will fly at a slower speed. Both aircraft will be at the same angle of attack however. The ideal instrument for this would be an angle of attack indicator. Unfortunately this instrument is seldom provided in light aircraft. It is however nearly standard equipment in jet aircraft.

So the heavier aircraft mass has to fly faster due to Newton's law and can glide farther because it will glide faster.

The wing design plays a crucial part in determining the lift ratio.
A glider has a longer wing span which reduces drag, but a fighter overcomes the drag of the shorter wing with power.

Also note that with a heavier aircraft, more lift is created because of the weight.
An aircraft's manoeuvring speed decreases with a lighter weight.

Answer 5

You are comparing apples to oranges here. Weight is not the predeterminant of glide range. It has to do with the aerodynamics of the wing, the loading ratio of the wing (pounds per square foot) and the overall drag of the aircraft. A C-152 can glide at something like 7:1, where a sleek airpus can do closer to 12:1. It has longer, skinnier wings (by comparison) and a much sleeker aerodynamic profile.

Answer 6

3 major factors contrubute to a high lift/drag ratio:
W/S (weight/wing area)
AR (aspect ratio, or span/chord)
Cdo (zero lift drag coefficient, the lower the better)

The airbus beats the C-172 in all three parameters. The wing loading is about 10 times higher, the AR is about 9 vs 7 and the Cdo is about .025 compared to about .035. This last is mainly because it has retractable landing gear and no wing struts.

Answer 7

No, that's not right. Glide has to do with weight and lift. The area of the wings is much more important than weight. Take a glider for example, extremely light, long wings, very good gliding.

Answer 8

glide rate depends on the Aspect Ratio of the aircraft, and of course every plane will be different or the same depending on the Aspect Ratio, that's why fighter aircraft can't glide for anything, while airliners and Cessnas are designed to at least glide for a certain range.