All I can think about is the location of doublers. I have used these to indicate the location of 1/32 ply doublers on solid sheet fuselage sides.
Howdy !
>
> Does anyone here know what the "filled triangle" and "hollow triangle"
> symbols refer to on scratch-build airplane
> plans? On my plans they are located in pairs in the side view of the
> fuselage pointed "Out" and usally in a pair,
> ie one solid triangle next to one hollow triangle. In the aft part of the
> fuselage there are only triangles located
> at regular intervals along the fuselage
>
> --
> Thanks !
>
>
> Matt
> seattle, WA
>
>