Taildraggers

When did aircraft designers decide to make the switch?

There were two factors that really led to the switch to mostly tri gear configurations, one is obviously the better visibility, but the the other is engines and their weight. On most early aeroplanes the weight of the engine was a big issue, since engines were often milled from blocks steel as opposed to being made from the modern lightweight alloys that typical aero engines are cast in these days, where only the cylinders are sleeved with steel. As a result of that design and technology difference, many old aero engines were pretty poor in terms of power to weight ratio, some having only one horsepower per two pounds of weight, although a few were a bit better than this.You can see that affecting aircraft design most evidently in WW1 fighter aeroplanes such as the Fokker Dr1 Triplane, Sopwith Camel, Nieuport etc, see this pic: http://en.wikipedia.org/wiki/Nieuport_17The noses of early aircraft are often extremely short, to the extent that the engine is sometimes actually underneath the top wing, with the wheels almost directly under the engine too, in order to support the weight. Placing the vast majority of the aircraft's weight near the centre of the aircraft does make it more maneuverable - and more unstable, which is desirable in a fighter - but the weight factor of the engines was the main reason for that positioning, so obviously, having a nose wheel would place more weight up front, even if the nose had been long enough to make such a layout possible, and was therefore best avoided.Tri-gears really started become the preferred choice in WW2 as power to weight ratios on engines improved, with some odd configurations tried in order to make that possible at first, one of the more unusual ones being the Bell P-39 Airacobra, see pic: http://en.wikipedia.org/wiki/Bell_P-39_AiracobraThe P-39 was the first production fighter to have such a landing gear configuration. It had the engine behind the pilot, driving a prop shaft to a propeller on the nose. This left plenty of room and weight capability up front, so it could have both a nosewheel and a big-&@($* cannon slap bang in the centre of the fuselage.The twin-engined Messerschmitt 262 jet fighter originally had a tailwheel, but it was found that the thing could not easily get up onto its main wheels without the pilot having to stab the brakes briefly on the take off roll in order to pitch the thing nose forward and up onto its main wheels so that the jet thrust would accelerate it fully and the wing would be at the right angle of attack for take off, needless to say, this was soon changed for a nosewheel layout. You can see the tail-wheel equipped Me-262 prototype making its maiden flight on this video: http://www.youtube.com/watch?v=h3VzThjMOdE&feature=relatedAl