Only his answer is wrong, Vabsie. The examples he gives are not relevant, as they are not typical light aircraft. I am not sure why he mentions single-seat agricultural plane I have never heard of in 20 years involvement in a variety of sides of aviation to a question in private flying.
You've never heard of the most common agricultural aircraft in the world, and used in every part of the world where agricultural aviation is conducted? Not that it matters, of course. Clearly the example went over your head, but was used as a worse-case example of a poor glide ratio...with an aircraft that has a power to weight ratio the same as the 172 in the example you created...the airplane you said couldn't possibly fly with a 3:1 glide ratio...yet somehow this airplane manages to do very well with even a lesser glide ratio. You don't get why that's relevant? It couldn't possibly be more relevant. What it does do is use a real-world example to show that you're tack here is far off base. A light single with the same power to weight ratio, a lesser glide ratio...and meets the criteria of your example, and it flies despite your predictions that such flight is impossible. How could this be??
SN3 also concentrates on prop drag, which is a problem that can be overcome but is also not as dominant as he suggests. Stopping a propellor cancels out 95% of prop drag, and can be achieved in a light aircraft. However a decision has to be made to do that or concentrate on the glide. Shutting down an engine in a light twin all commercial pilots train in at some point is far more relevant as a demonstration of the prop drag of a light single (similar power per engine) than one of four large radials in a big aircraft. Prop drag is important, but really ain't as much as he suggests. If it was it would be really important to stop the propellor in the glide, but except in marginal conditions it is not.
It very much is as critical as I suggest...with real-world examples provided to boot. In a typical single engine light airplane at lower altitudes, the average pilot may do more harm than good by stopping the prop due to the altitude lost while attempting to do so, to say nothing of the attention required which might be better served elsewhere. That, however, isn't relevant to the discussion...which first and foremost is why a student pilot shouldn't fear an engine failure in a light airplane...because AGAIN...the glide ratio is unimportant, whereas the landing at the end is important, and is entirely within control of the pilot.
What you have dragged into the conversation, needlessly and incorrectly, is the assertion that an airplane with a low glide ratio and the power to weight ratio of a typical light airplane couldn't fly...and that's not true. The fact is that the glide ratio of the airplane with a windmilling propeller has no bearing on the capability of the airplane to fly when under it's own power. It doesn't.
That's the point of the Dromader, in fact....used because it's a light single with a very low glide ratio under certain installations (as previously repeatedly described), the same power to weight ratio as the Cessna 172 you invoked, yet flies very well under it's own power...because the glide ratio has no bearing on the way it flies under it's own power.
Most light airplanes do well without power, because power doesn't create lift, contrary to your own assertions, and can easily trade altitude for airspeed (and thus lift) without any benifit of engine power or thrust, and even in the presence of propeller drag.
There's a reason why some propellers are featherable...because drag is so high.
Point being, your original assertions are incorrect, in the parallel you attempted to draw between powered flight and a windmilling glide. Most light airplane glide ratios are provided given a windmilling glide...and any references to stopped propellers are thus irrelevant to the discussion. You attempted to state that an airplane with a low glide ratio simply can't fly given the power a typical light airplane has...and clearly you're wrong....just as you're incorrect regarding the amount of drag a windmilling propeller creates and the energy it absorbs...again, in excess of the equivilent flat-plate area of the prop disc in many cases.
Forgot to mention that with that large prop the airflow is much slower than the little prop on a normal light single, so the sum changes giving more thrust under power as well as more drag when windmilling.
Your statement makes no sense. "Slower airflow" produces more thrust, you say? What are you trying to say when you say that a large propeller produces slower airflow? Are you trying to say a larger propeller is operated at a slower speed? You're invoking "newtonian physics," and attempt to suggest that moving mass airflow at a slower speed produces more "thrust?" By definition that defies several laws of physics, and while both interesting and incorrect, is also not particularly relevant to the original posters question, or your own assertions.
Shutting down an engine in a light twin all commercial pilots train in at some point is far more relevant as a demonstration of the prop drag of a light single (similar power per engine) than one of four large radials in a big aircraft.
Okay. I've also been unable to maintain altitude in a King Air 90 when a prop wouldn't feather. Also in an Apache. A Cessna 310. A seminole. Yada, yada, yada. Same thing, just not as clear an example of what happens to the airplane with good engines, even multiple good engines, fighting the drag of a single windmilling propeller. Yet another example that sailed right over your educated, newtonian head, in it's 20 year exposure to "a variety of sides of aviation.
You're not going to try to invoke rotor-wing flight again, are you?
Typical light aircraft have a much better glide ratio than he suggests, which is important to people who are planning flights, especially if there are areas where an engine failure would lead to a difficult landing - over water, woodland, mountains or other rough terrain. I have a friend who managed to glide just clear of the rough moorland hillside he had an engine failure over. Poor glide ration would have meant he could not have made the glide off the hills, and had he thought like that he would have concentrated on the wrong thing, minimising impact in a poor location, rather than achieving a safe landing in a good one.
You've never had an engine failure resulting in a forced landing, have you? Your thought process in the matter is still academic, based on what friends did and what you've read...perhaps it's easy to understand, then, why you don't seem to get it. It's becoming clearer.
Worked with a larger prop the force gets higher of course (because energy relates to velocity squared, momentum only to velocity, so the same energy produces less change of momentum if the speed change is higher. Force equates to rate of change of momentum), and with a helicopter rotor diameter much higher still, which is how it can fly.
Ah, well. You're really spinning off into left field now, and have returned to your helicopter discussion. You'd be far better off, and everyone better served, by starting a separate thread to tackle rotor-wing discussions, as they have NO bearing on the question asked by a student-pilot in this thread. What you are managing to do is little more than add incorrect information and confusion to a very simple question. Once again, we're talking about airplanes, here. Not helicopters. You seem to be troubled by examples using light single engine tailwheel airplanes and multi engine airplanes, but have no difficulty trying to introduce the dynamics of the helicopter.
That aside, your last paragraph makes no sense. Try it again.
How does one produce lift without power?
AIRSPEED!!!!!
Have you ever flown an airplane?
Have you ever seen a sailplane? Ever flown one? Ever shut off the engine in a light airplane and glided for a while? Lift is still produced, even with no power. Even with no engine. Imagine that. Airplanes even go back up, even perform entire aerobatic routines with full control, and plenty of lift...all with no power. Does this dazzle your mind? It really shouldn't.
Power is required for autorotation, otherwise one could autorotate and remain level. I suggest you find a physics text book and look up the meaning of the word power. I can assure you it will talk about conversion of energy. Energy can be in the form of potential energy or in the form of chemical energy before its conversion, but power is by definition simply a rate of conversion of energy.
Okay...you're back to helicopters again. Try to focus, will you? We're talking about AIRPLANES. The ones with the wings that don't spin around...take some time, look at some pictures, you'll see the difference. You appear rather confused.
I really have to question if you have any experience or training or education in flying an airplane at all. You don't seem to have a clue what you're talking about. I'll help you out, and then I think it's time to dismiss you as a troll and move on. A helicopter under autorotation is operating with the transmission clutch disengaged; the rotor is not under engine power or the influence of engine power at all. When we speak of powered flight, we speak of various types of internal combustion engines (in most cases) producing power to drive a propeller or rotor, or to produce jet thrust. A helicopter descending in an autorotative state is not doing so under an engine driven rotor, and is not in a powered state. This appears to be a new concept to you, or perhaps you're just overly arguementative...but your arguements have left the realm of rational discussion, relevant discussion, and now you're talking stupidly.
The only exception to powered autorotative flight is the autogryo, or gyroplane, in which the aircraft operates continuously in an autorotative state under power, despite the fact that the rotor itself isn't powered. That's far afield from the original poster's question, and as he's already stated that he's received the answer he desired, I'll end my discussions with you now, and leave you to your ramblings.