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I'm doing some estimations of weight and thrust loading for a college project, and in the formula below the landing distance is not a variable, but should be estimated using similar aircraft and usual runways. (There is also a formula for landing with the same problem)

T.C.Cork, Design of Aircraft

The similar aircrafts are 18-21 meter self-launching motor gliders like DG-505MB, DG-1001M or ASG 32 Mi (but with absolutely no data I have now, information about any other gliders would be appreciated as well).

The only thing I've found was that European Regulations CS-22 allow motor gliders a maximum takeoff distance of 500 metres.

Source; T.C.Cork, Design of Aircraft

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    $\begingroup$ Check the flight manuals, there should be plenty online (e.g. williamssoaring.com/fleet/ASG32_manual.pdf - the ASG 32 Mi needs 470 m to reach 15m taking off a hard runway) $\endgroup$ – Gypaets Nov 18 '18 at 16:55
  • $\begingroup$ Thanks! I just haven't thought of looking somewhere else than manufacturer's website. There seems to be no information about the landing distances though. $\endgroup$ – rafal.sz Nov 18 '18 at 21:08
  • $\begingroup$ The landing distance of gliders is typically smaller than take off distance and therefore not really of interest. I've looked and some motorgliders like the G109 have it, but I couldn't find powered sailplanes with that infomation. $\endgroup$ – Gypaets Nov 19 '18 at 20:13
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You may wish to obtain POH data from the 18-21 meter motor gliders you have listed and compare it to your calculated results. Also look into information such as wing loading, aspect ratio, takeoff speed (or stall speed), and airfoil type in addition to power source to include in your report.

Motor gliders, true to their name, should lift off well before 500 meters. Landing distance would be similar and also available in POH.

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  • $\begingroup$ Thank you! I thought that this was some secret data but it's just the fact that manufacturers don't post their manuals publicly. I found plenty of takeoff distance data, but there seems to be no information about landing distances. Would you think it's safe to assume equal landing and takeoff distances? $\endgroup$ – rafal.sz Nov 18 '18 at 21:05
  • $\begingroup$ I would not assume equal, comparable might be a better term, as takeoff can be more precisely measured. Generally, landings include how far down the runway, ground effect, flaps, braking etc. Since you are working with weight and thrust equation, why not focus on takeoff and use those distances for starters. Curious, what exactly are you trying to calculate? $\endgroup$ – Robert DiGiovanni Nov 18 '18 at 21:46

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