Martin Mars Build Thread (ivansplans.com)
Lots of info on these over at RCG, but I've not seen one here, so why not.
Just love watching videos of these dropping water in their role as fire fighters operated by Coulson Flying Tankers, from British Columbia, Canada.
This one spans 10 feet and weighs about 10 pounds. I'm going to use 4 outrunners for power, and hope to modify the design to pick up and drop water.
Here's the beginning of one hull side, made of mostly 1/4x3/16" balsa sticks. Ivan's designs are very light so they can fly slowly and realistically.