Is the simple wings frame(spar,ribs)of this maxair hummer structurally sound? I am asking because I'm considering using thesame wing design on my homebuilt ultralight.enter image description here

  • $\begingroup$ The wing has to withstand forces without breaking and at the same time have little weight. A very simple construction will be heavier than an optimized, more complicated design. Your choice. $\endgroup$
    – ghellquist
    Aug 29, 2018 at 20:47
  • $\begingroup$ This looks like a standard fabric-covered construction. That's how all aircraft were built in the first, say, 20 years (except the ribs were full, which is the only way to make them from wood and would probably be better when using metal too). Simple, but not extremely so (constructions like Rogallo wing are simpler still). $\endgroup$
    – Jan Hudec
    Aug 29, 2018 at 21:46

1 Answer 1


The simple answer is yes. There are many examples of working tube and fabric aircraft, both ultralights and larger designs, that make use of wing designs similar to your example.

The more complex answer is that it depends on a lot of things:

  • Did the designer anticipate flight loads correctly?
  • Did the designer model flight loads correctly when validating the wing design?
  • Do the materials used to construct the wing have physical properties close enough to the model used during design?
  • Was the aircraft built correctly according to the design?
  • Was the aircraft damaged such that the structure was compromised?

I don't want to discourage you from designing and building your own aircraft--one of the most exciting things about ultralights is how accessible they are to people with little or no formal training. Before you build and fly though, you should either learn how to determine the safety of a wing design using analytical methods, or stick to copying proven designs exactly.


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