Through training and still to this day, I keep on using these reference points to judge if I am at the right distance from the runway or the field I aim to land at (forced landing).

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    $\begingroup$ Use of such references is dependent on the aircraft. $\endgroup$ Mar 22 at 17:09
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    $\begingroup$ P.S. Your confusion is unclear and that is why you are getting the close votes. If you knew the exact glide angle of your aircraft, and depending on seat position you could correlate it to a feature on the airframe that would give you the ability to estimate whether a geographic feature such as a runway or field is above or below your glidepath, that would be useful. That is "how" it works, but a general statement for all high and low wing aircraft is neither accurate nor useful unless you put in some qualifying statements. $\endgroup$ Mar 22 at 17:36
  • $\begingroup$ Those little short cuts are just to get you started. You need to learn to judge those things just by the sight picture so aren't dependent on aircraft specific crutches like that. $\endgroup$
    – John K
    Mar 23 at 3:11

1 Answer 1


I suspect this is just a rule of thumb thing that works out just about right.

The geometry will have to do with the approximate height of your head vs the strut/aeileron, the altitude of your aircraft (when you commence a PFL) and the glide ratio of a typical trainer working out just about right to glide the distance to that point.

You simply do not have time to do complex calculations of glide range from the 1000-2000ft you would normally commence such an exercise. So a basic rule of thumb, that you can use by just turning your head, is as good an estimation as any. If it works, it works.


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