He died because his experimental light plane didn't work as advertised. I doubt his depression had anything to do with his risk-taking, given that most people I know with depression (self included) are complete slugs when in the midst of an episode. When just managing to take a shower and get dressed are herculean efforts, going hang-gliding or whatever he was doing isn't too likely. :-) So maybe his depression was at bay at that time.

Candy