in a larger number of accidents. In the
five years leading up to 2010, the number
of homebuilts had increased by about 15
percent, while the number of accidents
increased by only 8 percent.
Why the sudden drop in accidents
in 2010? While it would be nice to credit
various safety initiatives within aviation, their contribution was probably
slight. Accidents due to all major causes
dropped, not just in those categories
typically addressed by education efforts.
Add to that the fact that, overall, GA
accidents also decreased, reaching a
20-year low in 2010 (as reported by
the AOPA). Simpler forces are at work
here, affecting all private flying, not
The most probable explanation is
a reduction in flying hours. The cost
of crude oil nearly doubled from January 2009 to December 2010. The record
number of disaster declarations by FEMA
in 2010 indicates that weather may have
also been a factor. Coupled with general
economic woes, a reduction in flight
hours appears to be the best explanation
for the steep drop in accidents.
Of course, why accidents occur is just as
important as the totals. Forty-six cause
categories were tracked. For this report,
they were combined as follows:
Pilot Mis-control: Stick-and-rudder
errors on the part of the pilot. This
includes factors such as undershooting
or overshooting, ground loops, accidental stalls, etc.
Pilot Judgment: Decision-making
errors on the part of the pilot: continuing VFR into IFR conditions, running
out of fuel, CG mistakes, inadequate
preflight inspections, etc.
Mechanical Failure: Equipment failures
that were not attributed to mistakes made
by the builder or during maintenance.
Builder Error: Mechanical issues
directly traced to errors made during
Maintainer Error: Accidents attributed
to mistakes made during maintenance,
including failures to detect deteriorat-
Undetermined Loss of Power:
Accidents that were caused by a loss of
engine power, but for which the NTSB
could not determine a cause.