A few serious points -
In quite a few years as a mustering pilot as well as aircraft recovery for a dealer I have only seen 1 crashed Robinson which burnt(maybe they all ran out of fuel?!?!). Robinsons don't have a lot of frontal impact protection (hollow-point fibreglass projectile!!) but the fuel tanks rarely rupture. I am relatively inexperienced on the B47 but when I did my Ag rating in a Hiller 12E the instructing pilot told me that he refused to get in a B47 due to the fire risk if they crash!
A not so serious point -
The idea of fire retardent clothing is great so that if you manage to crawl from the wreckage you won't get burnt as you light the wreckage with your cigarette lighter. Not worth claiming pro-rata insurance to rebuild it!