Best Single Engine Glider?

[Lost man standing]

SN3

Ag planes are rarely if ever used in the countries where I fly most. I have no interest in ag flying. Why should I have heard of such a plane? Why does it have any relevance to private flying? What proportion of private pilots fly them?

There is one comment you make that proves you misunderstood all the relevant physics, therefore this is a bit of a pointless conversation. It is the response to my query about how to produce lift without power, by saying "airspeed".

Of course it is impossible to achieve any airspeed (above windspeed), or sustain airspeed against drag, without converting energy. Conversion of energy is power.

A sailplane uses the power in converting potential energy to kinetic energy to produce airflow and thus lift, and takes kinetic energy out of rising air to convert to potential energy and to kinetic energy in another direction. To a physicist that is still power. Power is just rate of conversion of energy. Without power a sailplane cannot fly.

I introduced the helicopter as an extreme example in the consideration of energy used to produce given thrust. The same power producing slower airflow has to move more air and will provide higher thrust. Large props produce low speeds of flow, and note that speed of airflow comes into all the calculations, so large props behave differently. It is standard physics, the same reason a high-bypass turbofan is more efficient than a turbojet. I was talking specifically about propellors, and in physical terms a rotor is a very large propellor, so it was relevant. It should be obvious that an R44 produces far more thrust from its 205 hp than an Arrow does from 200 hp, or the later would be able to hover on its prop.

Helicopters are also relevant if you start to make wild statements like "power doesn't achieve lift". It is a more direct example of power doing just that.

Note I never denied that a prop creates drag, but nor was I trying to make an accurate calculation, as the data are not easily available. In fact I pointed out that it always produces drag. However prop drag is related strongly to prop diameter as is thrust produced by a given power. That is why power of an aircraft with a large prop diameter and poor glide ratio is irrelevant to consideration of something like a PA28 or a 172, with a tiny prop which has a small, although measurable effect on glide ratio (or so I am told by someone who stopped it in the glide, cutting out 95% of prop drag, and made it a little further than otherwise, critically over the airfield fence).

You still haven't come up with any typical GA aircraft with a glide ratio less than 7:1. So what is the point of arguing the case for an ag plane that is irrelevant?