On Sun, 18 Jan 2004 08:38:29 -0700, Legrande Harris
wrote:

I think the main reason for a ballistic chute is a major structural
failure. So I guess it comes down to what the odds of a major
structural failure are. I think you are our resident odds maker so
what do you think?

In my analysis of the homebuilt accidents from 1998 through 2000, I count
about 30 cases of either structural damage or control failure on fixed-wing
homebuilts. That's out of about 606 total fixed-wing homebuilt
accidents...about 4.5% of the accidents. There was one additional accident
where the witnesses indicated the wing had failed, but the NTSB could not
verify it from the wreckage (happened at low altitude over a lake).

Of the 30 cases, 11 resulted in fatalities. One had a ballistic chute
(fouled on the structure during deployment). Three involved aerobatics.
One resulted from VFR flight into IFR conditions.

So, if the criteria is limited to fixed-wing structural or control failures
in non-aerobatic VFR flight, there were six accidents in the 1998-2000 time
period where fatalities might have been prevented with either a personal or
ballistic parachute. That's about 1% of total fixed-wing homebuilt
accidents.

This doesn't include the cases of in-flight fires (at least three, during
1998-2000), other common reasons for ballistic-chute use (engine failures
over hostile terrain, etc.), or those accidents which were not included in
the NTSB databases (ultralights, non-reported accidents, etc.).

Ron Wanttaja