Actually, the most common cause of general aviation accidents are pilot error. The most common cause of engine failure in single or multi-engine airplanes (or probably cars for that matter) is fuel starvation/exhaustion. Running out of gas will shut down any number of engines. The major risk of a twin engine airplane is loss of control of the airplane with engine loss on climb or during approach at slow airspeeds. This is occurs as a result of drag from the dead engine, torque from the operating engine both act to force a "VMC Roll" which at low altitude is fatal.<br><br>Military aircraft (helicopters especially) do a lot of low-level flight. This low level flight is often at night with night vision goggles enabling obstacle avoidance and high speeds. Helicopters don't do well with engine failures at low altitudes. Engine failures are treated by autorotation, trading altitude for rotor speed that will cushion the landing. A low altitude engine failure is a bad thing.<br><br>Any aircraft that loses power at night is in a serious hurt. The stress of a real (once in a lifetime) engine failure is bad enough, requiring prompt action. At night, there is little opportunity, if any, to find a suitable landing field, exclude hazards (wires, trees, fences, etc) and execute a safe landing that would be difficult under the best of circumstances.<br><br>The point is that all forms of transportation have their own risks and benefits. I would prefer to fly than drive.<br><br><br>Jeffery S. Anderson, M.D.<br><br>