Some people consider flying small planes very dangerous. Just how dangerous is it to fly in a light single-engine plane? For example, how does the fatality rate compare to driving a car, riding a motorcycle, etc.?
I get this question a lot from people who are apprehensive about flying with a private pilot. I'm afraid I won't be reducing these fears in any way. Let's review some general statistics during 2008. Note - these stats aren't specific to light or single engine aircraft:
NTSB reported there were 1.21 fatalities per 100,000 flight hours for private aircraft (Part 91 operators).
NHTSA reported there were 1.26 fatalities per 100 million miles travelled by automobile
We can equate that to about 2 million hours (estimating an average speed of 50mph). This gives us 0.063 fatalities per 100,000 driving hours.
Private aircraft have a fatality rate about 19 times greater than driving. It is also true that a majority of the accidents that occur are pilot error (71%) and could have been prevented.
There are risks involved when taking to the sky as a private pilot and understanding these risks is part of the continual learning process. The key to safety is performing careful planning, keeping current and proficient, knowing when to cancel flights or turn around and not to exceed your capabilities or the capabilities of your aircraft.
Since Geoff took the devil's advocate position, I'll play cheerleader.
If you look at the statistics another way, like AOPA does, you'll find that General Aviation has "about one-sixth as many accidents on a per-vehicle-mile basis" compared to driving.
Or to put it another way I'm 6 times more likely to get in a car accident driving to the airport as I am doing an equivalent number of miles puttering around in the pattern (my drive isn't that far - it's only worth a few laps around the pattern).
So now I've gone and left you with two essentially contradictory answers, both based on statistics from the same source, and both equally valid from a cold, unfeeling, numerical standpoint. But the answer isn't important.
Geoff and I are both really making the same point:
Each flight is as safe as the pilot wants to make it.
The pilot comes up with a plan for the flight, gathers as much information as they can about the weather, the aircraft, the route, etc., and then assess the situation.
They weigh the risks and determine whether or not the level of risk in making that flight is acceptable.
The statistics are useful. Most pilots I know spend a lot of time thinking about them (mainly why they're so lousy, and how we can make them better), but as a passenger remember they lump in the professionals with the students, and the conscientious pilot doing a thorough preflight with the one who haphazardly kicks the tire as he's climbing in for a 500 mile trip as his first flight in 6 months.
Which kind of pilot are you flying with?
Because I'm both a single engine pilot and motorcycle rider, the way I explain risk to new passengers is as follows:
Daytime flight over non-mountainous terrain: Like riding a motorcycle with full gear.
Daytime flight in instrument conditions or over mountainous terrain in clear air: Like riding a motorcycle with only a helmet.
Night flight over non-mountainous terrain: Like riding a motorcycle with a helmet but no headlight.
Night flight in instrument conditions over non-mountainous terrain: Like riding a motorcycle at night with a headlight but no helmet.
Night flight in instrument conditions over mountainous terrain: Like riding a motorcycle at night with no helmet, in the rain, over the speed limit.
Any flight in which the pilot says 'watch this sh*t' - Like riding a motorcycle at night with no helmet, over the speed limit, while drunk.
Flying a single engine airplane is more dangerous than 'driving to the airport'.
Flying in a small aircraft is far more dangerous than other methods of transportation (see statistics in other answers). I would not recommend it unless you have a positive reason to use a small plane. Thrill seeking or taking aircraft flights for "fun" is not a good idea from a statistical point of view. I fly strictly for practical reasons and I would recommend that as a general policy for anyone considering flying either as a pilot or a passenger.
Flying in a small aircraft is not as dangerous as base jumping or scuba diving.
Pilot nature, skill and attitude have a large impact on the danger in a flight. Most people get killed in small planes because the pilot did something that was either foolish (like taking shortcuts in the pattern), reckless (flying into storms) or because they panicked. If a pilot acts cocky, that is a huge warning sign.