aerodynamic stability to glide down to emergency landing area should problem arise.
more power efficient in cruise flight.
more power efficient in cruise flight.
For General Aviation safety, read the Joseph T. Nall report: https://www.aopa.org/-/media/files/aopa/home/training-and-sa...
To summarize, helicopters and airplanes enjoy a reasonably similar lethality. Approximately 15-20% of accidents (total) are fatal to one or more occupants. However, if you break it down to fatal-accidents-per-100,000-hours then helicopters are worse (1.5 vs 1.0) at least in 2013.
When it comes to general aviation safety, however, the far and away most important factor is the pilot. Unless you get damned unlucky, the vast majority of accidents are either avoidable or survivable if the pilot doesn't do something wrong. In helicopters, a controlled autorotation will be survivable most of the time. In airplanes, a controlled forced landing is the same.
Of course, you can have your cake and eat it too -- I recently purchased a Cirrus SR22-TN (airplane) which has a Ballistic Recovery System aka a parachute. If anything goes wrong you can pull the chute and the entire airplane will descend to the ground. :-)
In a airplane, a loss of engine power translates to slowing down. If you're on top of things, you will notice this and nose-down in order to maintain airspeed. If you fail to notice this, your airplane will stall, but even that can be recovered from by nosing down in time.
In a helicopter when you lose power this translates very quickly (with 4-5 seconds) into loss of rotor RPM. Within 1-2 seconds you must change the angle of the blades in order to enter the autorotation configuration - if your rotor speed drops below a certain RPM before you make this change, you drop out of the sky with no chance of recovery. Making this an automatic reaction is a big part of helicopter pilot training.
Once you have entered autorotation/glide, the next challenge is finding a suitable place to land. In both cases you ideally need a flat hard open surface, though airplanes generally need a longer area than helicopters. Unfortunately a helicopter has a very poor glide ratio - ~5:1 (5 feet horizontal for 1 ft vertical) while a light airplane has something like ~9:1 glide ratio. Furthermore most helicopters cruse at much lower altitudes (1K-3K ft above ground level) vs. light airplanes cruising 4K-8K ft AGL). So you end up having 1/2 to 1/4 the time and distance to find a suitable landing site.
When it comes to the actual landing itself, gliding vs autorotation are different but one is not necessarily more dangerous than the other. In both cases you have a well-defined set of ideal airspeeds, descent rates, etc. which will lead to everyone surviving the experience. And in both cases you don't earn your pilot license until you have demonstrated that you can consistently do this correctly.
One more nuance - light airplanes (eg: Cessnas) are easier to glide than heavier/faster airplanes because everything happens slower. Since light airplanes are also the cheapest to operate, they are most often found in the hands of new/inexperienced pilots - it is good that they are forgiving.
Meanwhile light helicopters like the Robinson R22 are actually much more difficult to autorotate than larger/heavier helicopters - everything happens faster and is less stable. Unfortunately since these helicopters happen to be the cheapest to operate, they also very often find themselves in the hands of new/inexperienced pilots. This was such a big problem that there is a special piece of federal aviation regulation (SFAR 73) which puts additional training requirements on pilots specifically for the Robinson R22 and R44 models.
In the big picture though, general aviation is incredibly safe. The vast majority of non-commercial accidents can be attributed to some form of human error - either poor pilot judgment or lax adherence to maintenance requirements.