Pilots are written down as the Primary cause, but the secondary cause can frequently involve the pilot operating the engine badly. For example: a pilot forgets

Pilots are written down as the Primary cause, but the secondary cause can frequently involve the pilot operating the engine badly. For example: a pilot forgets to turn on the carb heat on descent, leading to loss of engine power, and crash short of the runway. Primary cause is pilot error. The engine on a small plane is failure prone, and easy to make mistakes on. The Beavers in question are operating on an engine design from the 1930s (Pratt and Whitney Wasp 985). The major compnonents on those engines likely haven't (and can't for bureaucratic reasons) changed since the 50s. On a plane like the Beaver, a majority of the gauges are devoted to the engine. If you get a chance to fly on one of these, you'll notice that a majority of what the pilot does pre-takeoff is engine checks. Making the engine simpler is making it easier to fly the plane, and eliminates another source of pilot error.