How do you know 'when' an aircraft has stalled?

[Teckair]

If this is incorrect someone correct me, But I do believe Thrusters need a lot of forward stick to 'stay flying' when the power is idle, due to the amount of drag, they are draggy little planes... And remember: Stalling only has to do with the Angle of Attack. I think some people are thinking it is to do with airspeed... If you dont exceed the critical angle of attack, but are low airspeed and descending, chances are you havent stalled.

By staying flying I mean not stalled which is what will happen without forward stick when the power is off, this used to bring a lot of GA guys undone in the early days of ultralighting and in fact gave ultralights a bad name and led to the AUF changing it's name.

 

 

[Teckair]

Does a thruster pitch up into a nose high attitude when the power is brought back to idle?

No, but due to drag it will slow instantly and stall if the appropriate action is not taken, this is much the same for many of the slow flying rag and tube style aircraft.

 

 

[turboplanner]

So much incorrect data here, turbo, please get it fixed. We can't let this forum be like a discussion - you must correct each post the instant it appears. Have fun, bye.

Not me DJ, your question, your fallout.

 

 

[djpacro]

No fallout - people are free to discuss.

 

You are the one who wanted every single statement to be correct.

 

Not my question here - I have anwered it to those I have discussed it with, yeah even answered it here but you didn't like it so I deleted my posts.

 

As for your allegation that thousands of people saw that question buried elsewhere on the internet, gee, even my close friends who frequent that other place did not notice it - and if thousands (more likely a dozen) did go and read it - great.

 

Every pilot has practiced stalls - presumably they know whether they did it or not, if not its time they considered what it was they actually did at the time. Don't need to know any theory just the practical knowledge of what your aeroplane does when it stalls.

 

... the stall stick position is always the same for a given loaded configuration and therefore flight.

Suggest you consider this statement some more - anything which produces a pitching moment is a factor and therefore will change the SSP to the extent determined by that pitching moment change. Some-one demonstrates SSP in an aeroplane where the cg is pretty much the same every flight, no flaps and minimal pitch change with power that is fine but doesn't mean you can extrapolate that information to other types.

[David Isaac]

Suggest you consider this statement some more - anything which produces a pitching moment is a factor and therefore will change the SSP to the extent determined by that pitching moment change. Some-one demonstrates SSP in an aeroplane where the cg is pretty much the same every flight, no flaps and minimal pitch change with power that is fine but doesn't mean you can extrapolate that information to other types.

Thanks David, I appreciate your input. The dangers of being technically too general for simplicity sake on my part.

 

In the context in which I was referring to SSP I was speaking in terms of an ordinary aeroplane that a typical pilot would fly through a range of normal maneuvers (a loop and roll being normal in this context) in conditions where the Cof G and weight are constant for the particular flight and the wing shape remains constant (no slats, flaps excetera), so in that context the SSP position is constant and should give a pilot an accurate feel for stall onset and stall. Do you agree?

 

P.S. I am going to email you regarding another matter.

 

 

[facthunter]

Generalising.. With Aircraft that have the engine thrust line displaced from the line where the drag acts, there will be a large pitch effect when the power is put on or taken off. Some aircraft have a large pitch change when the flaps are lowered, similarly, because the lift line shifts (rearwards usually).

 

Another fact is that the elevators are your method of getting the wing to be at the angle you want to the airflow, ( relative) for the aeroplane to perform the way you want it to. The fuselage is attached to the wings at a fixed angle ( the riggers angle of incidence) so it moves with the wings (We all know that but a plane could be designed otherwise)..

 

I can't think where a plane would stall without the pitch control coming into it. I include the trim in that and assume that the CofG hasn't been altered.

 

Take a plane like a Thruster and close the throttle. and do nothing, ( except move the rudder a little to stop it turning). It certainly will lose a lot of it's speed quickly, and normally you pitch the plane forward rapidly and get the plane to a fairly steep nose down attitude to maintain a safe manoeuver speed, which is probably less than 10 mph below your normal cruise speed, if you intend to do some turning.

 

This requires a fair bit of forward stick force, but I don't believe the plane would stall if you didn't , not the least reason being, that you need ALL of the backstick to three-point it, when you are landing., and even then you have difficulty getting the tailwheel to contact at the same time as the mains.

 

. .If you are balloon busting, streamer cutting or mock combat, you can legitimately regard a certain stick position as being where the stall happens, and I can't see it as being a concept that will get you into much trouble. In fact I think it is a big safety plus.

 

The pilot is the cause of all stalls that I can think of where the plane is in normal conditions . Nev

 

 

[dazza 38]

OK Folks.I am going too quote directly from Fly Better.In the hope that, people who have not read it.Understand where I and others are coming from.I agree with all of Noel Kruse's statements im about to type here.If people do not agree, thats is perfectly OK.I would like to know though, the reasons for not agreeing.Just to see others point of view.

 

Book one- Aerodynamics Page 231

 

"An aeroplane can be stalled at any Airspeed and in any Attitude or Not stalled at any Airspeed or Attitude.

 

It all depends on where YOU put the stick.

 

Page 234- General symptoms of a approaching stall.

 

1- Stick position moving towards the Stick Stall Position

 

2-increasing control and airframe buffet

 

3- maybe a electric warning horn.

 

4-Finally with the stick at (or beyond) the stall position,the aircraft departs from the desired flight path.

 

WHERE THE NOSE IS POINTING AND WHAT THE AIRSPEED IS , IS IRRELEVENT.

 

I have typed some things in capitals, the reason is that it is Highlighted in the book.Nothing to do with anger or anything.I thought i better mention that incase somebody gets the wrong idea.