As I've now seen and recognize your posts for what they are and where you're trying to go with them; I'll answer accordingly. But first I'm going to ask for clarification, because (as usual) you've already gone off on tangents that give windows for you to challenge the answers (that's what you're really after (and that's OK. I like debate.discussion too         )).  

Will we agree that sans thrust, all drag is parasitic ?

We're going to have to pick a wing "type" too. Your statements/questions make huge assumptions on L/D and where it peaks/diminishes. Your relationships between L/D, airpseed and RoD are far from universal.

I'm not touching the no-thrust questions. You're posing impossible scenarios there. Your large wing held at 80 degrees AOA with no thrust would end up having REVERSE airspeed.. IF that AoA could even be held..  (hold off on the AoA versus pitch-angle stuff.. you know what I'm attempting to point out)..

Quote:


LOL  (not that kinda stall)

Sounds like, in your zeal to cover the question in the greatest detail possible it ends up appearing vague and, at times, self contradictory (is that proper grammar?) "....i.e. ".....A plane with zero forward airspeed still cannot drop out of the sky at any high speed ....." I'll try my best though....

chornedsnorkack wrote on Jan 4^th, 2007 at 4:15am:
During a stall, the normal flow of air is disrupted and the normal flight or control of flight is affected. The reason I choose this wording, as opposed to the standard textbook answer, is that an airfoil refers to any airfoil and all airfoils (cannards, vertical stabilizers, horizontal stabilizers etc.) can experience a stalled condition.
At "high angles of attack" both lift and drag are high.

Quote:

Firstly, just as a matter of clarification, reduction of thrust will, on most propeller driven aircraft, mean a reduction of lift. This is due the absence of accelerated slipstream (accelerated air) over the wing.
This aircraft would only fly at "best glide" (assuming a modern positively stable aircraft) if it is trimmed for best glide speed. Otherwise, Hagar’s scenario of series of descending stalls and recoveries would apply or, at the other end of the spectrum, a condition of excessive speed, resultant lift and then finally a climb, ultimately followed by another descent, and so on..... will be the result.

Quote:

This tends to fall into the realm of the "utterly ridiculous" phase of the "lift vs AOA" discussions. Unless you're flying an F-16 or SU-26, vertical flight will only be transitional. This takes us right back to dynamic and static stability. Yes if you really want to take your Cherokee and point it straight up, if only for a moment, with enough forward airspeed, it is possible. I I've done it know some guy that did it.  You have to ask the question; What makes the airplane "go up" for the short period that it does? Inertia. In this case, thrust and inertia are overcoming weight. Once the momentum has been lost, we fall back into the realm of the horizontal, aerodynamic world.
Firstly, the aircraft will fall and then weathervane into forward oriented (hopefully) flight, while pointing straight down. As speed increases, lift increases and a nose-up pitching moment is created by the wing. Eventually, the aircraft will stabilize into the previously trimmed AOA.

Quote:
Does the word contradiction mean anything to you? Unless your theoretical wing is very big and full of helium, it must move in one direction or another. Without thrust or inertia, that will be forward (hopefully) and down, with the rate of each being inversely proportional to the other. Even in a stalled (or "parachuting") condition, the wing produces some lift and is still affected by gravity.


Quote:
I think you might be talking about the same thing. If you literally mean a wing with a parachute attached, I would have to say slower.

Quote:
As opposed to your 90 degree scenario (and even that wing produces some lift with a positive relative wind.....we'll save that for a later discussion)This wing, with a enough relative wind, will still produce lift perpindicular to the relative wind and counter to gravity.  

Quote:
You're really going after the wrong factor in the equation. To understand this better, you need to focus on the relative wind. The airfoil doesn't change. The AOA relative to the airflow does. At "the back of the power curve" the wing is at an extreme angle to the relative wind.  Air flowing over the wing has to make an exaggerated curve over the top of the airfoil. At the point of stall the "curve" becomes too great. The airflow can't make the turn and "tumbles", instead of flowing smoothly.

chornedsnorkack wrote on Jan 5^th, 2007 at 6:25am:

You obviously have a good understanding of aerodynamics but this sort of discussion is in danger of becoming far too technical & you end up not seeing the wood for the trees. What seems logical in theory is often very different in practice. Let's go back to your original question & scenario. Quote:

This is a very good description of a glider or sailplane. Even the most efficient modern sailplane is severely underpowered as it has no power at all, yet it can stilll fly under full control & even do aerobatic manoeuvres. The same basic rules apply to gliders as to all conventional aircraft. I've found that this confuses the general public terribly & when flying my R/C model sailplanes & aerobatic slope-soarers I've lost count of the number of times I've been asked "How can you control it without an engine?"

The point is that a stalled aerofoil (airfoil) produces no lift at all. Once the mainplane is stalled it would be impossible to hold the aircraft in your example at an AoA of 80 or 70 or 60 degrees for any length of time without the nose dropping. Therefore your "parachute" theory is also impossible. The aircraft is at the mercy of gravity until remedial action is taken. I'm talking about conventional aeroplanes here & it's very difficult (practically impossible) to stall pure canards & deltas. These tend to "mush" at low airspeeds & high angles of attack while steadily losing altitude which is more like your description of a "parachute".

Quote:

This is a long way from your original topic. All aircraft have to pass stringent testing by the appropriate authorities before they're certified for flight. This includes stalling & spinning characteristics in all normal configurations. The 'deep stall' phenomenon with high-set "T-tails" was first experienced with jet arliners back in the 1960s. It took the death of BAC test pilot Mike Lithgow in the prototype BAC One Eleven in 1963 before this condition was fully appreciated. Although he must have known he was doomed he talked it right down to the moment of impact over the radio. I've heard a recording of this & it's very moving. Investigations & research following this unfortunate accident helped to make the One Eleven one of the safest airliners of its time. The lessons learned were also passed to other aircraft manufacturers. http://oea.larc.nasa.gov/PAIS/Concept2Reality/deep_stall.html

Quote:

See my above comments on canards & deltas. There are also various high-lift devices to delay the stall or make it almost impossible in normal circumstances. One example of a light aircraft designed from the outset to be almost impossible to stall or spin is the Ercoupe. http://www.gatwick-aviation-museum.co.uk/ercoupe/ercoupe.html
I still have mixed feeling on this idea myself.

chornedsnorkack wrote on Jan 5^th, 2007 at 9:08am:

Not my idea of conventional or typical. The example in your original question is a light aircraft so I assumed this was what we were discussing. The jet airliner with T-tail + swept-wing combination is a comparatively recent development. The rear-mounted engines might also have contributed to the problems.

These posts aren't, nor ever have been, about answers. It's mental/written thumb wrestling.

chornedsnorkack wrote on Jan 5^th, 2007 at 9:08am:
You seem to be fixated on this whole "deep stall" idea. Unfortunatley, that's usually only an issue for Hollywood TopGun actors and Test Pilots. The above hightlighted text is not entirely accurate. The problem with modern, swept wing jets (whether T-Tail, conventional tail, low-wing, high-wing etc. etc. ) is that they have a swept wing. By that distinction, they ALL stall at the wing tip first.
The reality of the matter is; very few if any modern jets fall victim to stall related accidents during normal operations and day-to-day flying. I challenge you to show me a recent accident that occured as a result of failure to maintain proper flying speed (or even an accelerated stall incident). The Wellstone accident is the only one that I can recall and that one isn't even a "swept" aircraft.