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Early talk
Actually a hang glider has a glide ratio of about 15, with even 17 for a rigid hang glider.
Open-class sailplanes such as a Nimbus 4 or ASH25 probably have glide-ratios of approximately 60:1 but such small angles are difficult to measure
VASI links here, redirected from "glide slope". Somebody should fix either the redirect or this page to talk about what glide slope means in approach procedures.
Glide slopes ARE different from this issue and should not be redirected here. The correct info for a Cessna 150 (about 8.8:1) is available from its POH (Pilot's Operating Handbook, a relatively new term in FAA parlance). You'd measure a 60:1 glide angle by, say, a release in still air at 100 feet AGL or so, and seeing if you'd go a nautical mile, over flat terrain. —Preceding unsigned comment added by Tszekely (talk • contribs) 21:15, 10 September 2007 (UTC)
Merge with Lift-to-drag ratio
Looks like ""Glide ratio, also called, Lift-to-drag ratio" and that "The terms glide ratio and lift-to-drag ratio are interchangeable", according to this article. So a merge seems to make sense. Yet I know nothing about this... - Nabla (talk) 17:40, 6 August 2008 (UTC)
- I suppose the optimum glide ratio and optimum L/D are different though. The Gimli glider managed 12, whereas a 767 should be nearer 18.- (User) WolfKeeper (Talk) 22:37, 6 August 2008 (UTC)
- I guess they happen to compute to the same value, but strictly speaking they have different definitions:
- glide ratio is the ratio of horizontal distance made to altitude lost, i.e. a ratio of lengths
- lift-to-drag ratio is the ratio of the lifting forces versus drag, i.e. a ratio of forces
- I haven't looked deeper into how the literature uses these terms, but maybe saying that they are synonyms is not putting it quiet right.
- If the two articles are merged, it should be pointed out that:
- they are strictly speaking two different things
- in most applications they have the same value so they can be considered interchangable
- the underlying reason for this: when gliding with constant velocity, all forces must some up to zero (as vectors), so drag and lift just add up to the negative of gravity. Drag (by definition) is parallel to the velocity vector and lift is perpendicular, hence the ratio of lift-to-drag is equal to the ratio of horizontal speed to vertical speed, hence is equal to the glide ratio. A simple diagram of the forces might help illustrating this.
- 67.180.29.122 (talk) 07:46, 9 August 2008 (UTC)
There is now an article on gliding flight. Most of the information in glide ratio is now in this. I think that Lift to drag ratio can remain and that this article can become a redirect to gliding flight. JMcC (talk) 17:17, 9 April 2009 (UTC)