Pilot error actually is 78% of all accidents, according to the NTSB
(http://www.ntsb.gov/Publictn/1998/ARG9801.pdf, Annual Review of Aviation
Accident Data - U.S. General Aviation, Calendar Year 1995):
Seventy-eight percent of pilots involved in accidents were cited as either a
cause or
contributing factor; in fatal accidents, 87 percent of pilots were cited. The
environment
(including weather, light, objects, and terrain conditions) was cited for 41
percent of accident-involved
aircraft and 39 percent of those in fatal accidents. Thirty percent of the
aircraft involved
in accidents were found to be a cause or contributing factor; 21percent in fatal
accidents.
Being a pilot myself, I am quite sensitive to numbers like the one you gave
without source.
-JoeF