Hi,
1. Lack of a tailplane gives a couple of advantages:
- the fuselage can be shorter, what gives less drag from the fuselage and less weight;
- the fuselage can be lighter even more, as it doesn't bear any loadings from the tailplane - so its construction can be more fragile; the tailplane itself is a little bit troublesome at high speeds, as e.g. it often tends to vibrate, it can also cause problems in certains angles of attack;
- there's no drag from the tailplane; these drag problems are even more important in high speed flight (OK, 'high speed' in 2nd WW standards, i.e. around 800 km/h and faster
) where drag is rapidly increasing.
2. Yes, you are right.
Swept wing has of course another advantages in high speeds (lower local speed of air flow), but this knowledge was barely being born in the final stages of the 2nd WW; but swept wings were commonly used in tailless designs from the early 20th century.
3. Not exactly; let's imagine two aircraft, a conventional one and a tailless one, both with the same engine, fuel load, armament, purpose, etc. Generally the tailless one will be lighter, with better power-to-weight ratio (that's what I meant 'powerful'), faster (due to smaller drag and less problems at high speed) and probaly also more maneuverable. Not accidentally the Komet had such excellent glide characteristics, that people observing it in glide couldn't believe it flew with no power. Lippisch strongly opposed to an idea to equip the Komet with a tailplane (born at some moment due to certain problems experienced), what - according to his point of view - would ruin Komet's aerodynamical quality.
But we have to remember one more thing - the Komet was an early trial to built a high speed aircraft, when high speed flight was still a pretty mysterious area. The relatively simple shape of the Komet simply caused less problems at high speeds. The 'improved Komet', Me 263 with its longer fuselage and a teardrop canopy (but the same wings and fin) had actually lower allowed Mach number - 0.8 as opposed to Komet's 0,82 (and was generally heavier and slower, even with a more powerful engine), what means that the aircraft showed undesirable signs of nearing to the speed of sound at lower speed of flight.
Tailless aircraft hasn't become popular as they are really hard to design well, while almost the same quality can be achieved in more conventional way.
Tendency to climb is a fault rather than an advantage of a tailless design. As everyone who built a flying aircraft models knows
, a conventional aircraft has its centre of gravity in approx. 1/4-1/3 of the wing chord. The tailplane simply counters any pitch deviations in the same fashion as a tail of a kite - the tailplane has basically no other influence on aircraft's behaviour in flight (save for steering of course
).
Canards and tailless aircraft (including flying wings) are nose heavy, i.e. their COG is placed more forward than in a conventional aircraft, what would cause it to dive instead of glide. This 'diving' momentum is balanced by opposing ('climbing') momentum produced by a canard (i.e. forward mounted horizontal stabilizer) in case of a canard aircraft, or selfstabilizing wing profile or twisted sweptback wings in case of a tailless aircraft. As the 'climbing' momentum is produced by airflow, it varies with varying speed and needs to be countered every time a canard or tailless aircraft changes its speed but has to stay at the same pitch. Simply - a tailless aircraft strongly rises its nose when accelerating, while decelerating makes it to dive.
Kind regards
Grzesio