I’m looking for the most capable in terms of payload relative to own weight heavier than air vehicle of any type, size or era. Untested designs are of interest too.

Essentially, what is the most efficient way to fly?

I suppose that ultimate vehicle is probably made of top-end composite materials, uses high lift devices and is electric as batteries doesn’t count to the empty weight.

I have done a fair research on the topic from unmanned rc models to Stratolaunch, and so far the best discovery is https://www.nestofdragons.net/weird-airplanes/special-facet-opal/ with 1.73 ratio. This particular aircraft is a very old design and quoted numbers may be not realistic, so I wounder what is the modern record keeper?

  • 1
    $\begingroup$ Take a letter, fold it into a paper airplane and throw it. Payload fraction = 1. $\endgroup$
    – user71659
    Dec 16, 2022 at 21:33
  • $\begingroup$ Batteries don't count towards the empty weight?! Because unless you have the option to remove them they are part of the aircraft and reduce your payload. $\endgroup$ Dec 16, 2022 at 21:35
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    $\begingroup$ Off the top of my head Rutan's Globalflyer: empty weight 1'700kg, take off weight 10'000kg i.e. 0.17 empty-weight fraction. The aircraft you linked had an empty-weight fraction of 0.4 a quite extreme value for homebuilt composite airplane... its end might suggest that it was indeed structurally too extreme $\endgroup$
    – sophit
    Dec 16, 2022 at 21:40
  • $\begingroup$ fuel apparently also counts as useful load, hence no need for electric. There's that thing with counting fuel / batteries as useful load, it's really a bit pointless. What you want really is $\endgroup$
    – Apfelsaft
    Dec 21, 2022 at 7:09
  • $\begingroup$ Judging from your comments, you want best payload weight per unit of drag (which equates to "best energy per payload per distance"). Please edit your question accordingly. $\endgroup$
    – Sanchises
    Dec 25, 2022 at 20:00

1 Answer 1


I guess the lightest aircraft w.r.t. payload will be something like a paraglider .. as an example:

ozone XXLite 19: Glider weight 1.37 kg for payload (pilot) 115kg (https://www.paraglide.co.uk/store/ozone-xxlite-lightweight-paraglider-p-117), so that's approximately 1.2%.

I assume that even with a paramotor the ratio $m_{payload} / m_{TOW}$ still holds as "quite good".

  • $\begingroup$ well, technically this is correct answer, but so would be a tethered kite with even higher useful payload fraction. $\endgroup$ Dec 22, 2022 at 15:11
  • $\begingroup$ There are also very capable wing-shaped airships filled with helium which are net havier than air utilizing aerodynamic lift to fly, but I guess the word "rigid" is missing in the title to meet original expectations $\endgroup$ Dec 22, 2022 at 15:21
  • $\begingroup$ Ok - first, commenting on the kite: i don't know why a tethered kite would have a higher useful load? $\endgroup$
    – Apfelsaft
    Dec 24, 2022 at 5:50
  • $\begingroup$ Concerning the rigid aircraft .. a counter question: is there a specific reason it needs to be rigid? $\endgroup$
    – Apfelsaft
    Dec 24, 2022 at 5:54
  • $\begingroup$ The question is about most efficient way to fly, and all those strings on a paraglider and pilot's harness makes a lot of drag. I think I'm looking for best energy per distance per payload. $\endgroup$ Dec 25, 2022 at 14:50

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