Can anyone point me to statistics on the safety record of gliders vs. single engine general aviation aircraft?
I had three days to burn so I took a look.)
Comparative data was very difficult to find beyond accident counts, so determining relative safety is problematic. No one that I could find tracks or estimates the number of flights/hours for gliders, even the Soaring Society of America, so this is all interesting but essentially meaningless. Even if such data existed, the difference in use models would cause problems making a fair comparison. So now that I've told you this was a waste of my time to compile, I will make you waste your time to read.
If you could extrapolate single mode pilot certificate counts to a common usage basis, flying a glider is 2.5x safer than flying an airplane, but of course you can't.
NTSB accident count for 2017 shows 56x more airplane accidents and 90x more fatal airplane accidents than glider accidents.
- 271 fatal and 972 non-fatal GA airplane accidents, total 1243
- 3 fatal and 19 non-fatal GA glider accidents, total 22
US Civil Airmen Statistics shows 18x more airplane only pilots than glider only pilots, with 40-80% of both numbers muddied by multiple certificate pilots.
- 14k registered glider only pilots
- 24k registered glider pilots with multiple certificates
- 260k registered airplane only pilots, excluding ATPs
- 190k registered airplane pilots with multiple certificates, excluding ATPs
AOPA had a report for 2009 for all general aviation where the accident rate per 100k hrs is 7.2, and a fatal rate for the same of 1.33.
It is hard to compare because of hours flown... I looked at glider accidents for the last 18 years. There are a lot of non fatal accidents. Fatal glider accidents (no particular order) seems to be in-flight break up, stalls and collision with ground (typically in mountainous terrain). Tow accidents resulting in stalls or loss of control is another critical phase of flight it seems. There are different tows like car, wench and of course tow plane. (I am not a glider pilot but ATP, CFI fixed wing.)
One thing gliders have going for them is the slow stall and sink rate. So even an off field landings should be survivable as the speeds are slow. On the other hand there is not a lot of structure around you. High performance gliders put the pilot stretched out in the very front of the air frame. Fiberglass or Carbon fiber does not bend and absorb impact, it reaches it's limit and ruptures. Aluminum airfares typical of powered fixed wings tend to bend and absorb some energy.
I found a blog post that answers the question by using commercial aviation as a metric.
General aviation (US)
- 1 death in 64,000 hours
- 156x as dangerous as commercial aviation
Flying sailplanes (Germany, France)
- 1 death in 50,000 hours
- 200x as dangerous as commercial aviation
The following graph shows the relative difference between sailplanes and powered planes:
Charts and sources at this link.