Accident Statistics: Certified vs. Non-Certified Engines

Ron Wanttaja wrote in message . ..
A while back, I posted the result of a cursory look at the accident
statistics for aircraft powered by auto engine conversions. It *was* an
awful shallow pass, and at the time I promised to look into the issue
deeper.

I have since obtained the NTSB accident databases for the years 1998, 1999,
and 2000, and am ready to provide more exact figures.

The nice thing about the accident databases is that they usually describe
the type of engine that powers the aircraft. Unfortunately, the FAA
registration database is a lot more vague. A lot homebuilts are merely
described as having experimental engines; a number don't even have an
entry. So we can't do the classic "x% of auto engined-airplanes have
accidents every year vs. y% Lycont-powered planes."

Does this take into account things like modified Lycomings? We have
an O-360 with an Ellison TBI. It isn't a certified engine, but it's
not an auto conversion or rotax or something either.