Stalls and Angle of Attack.......(Split)
Thread Starter
Joined: Oct 1999
Posts: 3,325
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From: UK
Only three things cause any given wing in any given configuration to stall:
1) Angle of attack
2) Angle of attack
3) Angle of attack
Absolutly nothing else will. So think 'AoA' when you fly, not speed, and all will be well (aeros will teach you that). The most significant instrument missing from the average GA panal is an AoA indicator - there's plenty of stuff on the Chippie's panel I'd gladly swap for one.
SSD
1) Angle of attack
2) Angle of attack
3) Angle of attack
Absolutly nothing else will. So think 'AoA' when you fly, not speed, and all will be well (aeros will teach you that). The most significant instrument missing from the average GA panal is an AoA indicator - there's plenty of stuff on the Chippie's panel I'd gladly swap for one.
SSD
Joined: Jun 2003
Posts: 13,787
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From: EuroGA.org
True, however this is not a terribly helpful explanation because the AOA is the final result of everything that causes the air to flow over the wing.
That "everything" includes the effect of the propwash, which (for this aircraft type) would be flowing over the inboard portion of the wing. So I would expect a slightly lower stall speed if the engine power is higher, particularly as many wings are designed to stall inboard first (for aileron control reasons).
But it would not be a strong effect.
That "everything" includes the effect of the propwash, which (for this aircraft type) would be flowing over the inboard portion of the wing. So I would expect a slightly lower stall speed if the engine power is higher, particularly as many wings are designed to stall inboard first (for aileron control reasons).
But it would not be a strong effect.
Thread Starter
Joined: Oct 1999
Posts: 3,325
Likes: 2
From: UK
Originally Posted by IO540
True, however this is not a terribly helpful explanation because the AOA is the final result of everything that causes the air to flow over the wing.
That "everything" includes the effect of the propwash, which (for this aircraft type) would be flowing over the inboard portion of the wing. So I would expect a slightly lower stall speed if the engine power is higher, particularly as many wings are designed to stall inboard first (for aileron control reasons).
But it would not be a strong effect.
That "everything" includes the effect of the propwash, which (for this aircraft type) would be flowing over the inboard portion of the wing. So I would expect a slightly lower stall speed if the engine power is higher, particularly as many wings are designed to stall inboard first (for aileron control reasons).
But it would not be a strong effect.
In aeros the concept of 'loading' and 'unloading' the wing (increasing and decreasing AoA) is vital, and becomes second nature.
But you are correct in that we can only judge AoA rather imprecisely (though if we train ourselves to 'think' AoA rtaher than airspeed many stall/spin scnarios would be avoided), hence my call for an AoA indicator - common only in fast jets and Concorde, but not a particularly complex bit of kit.
SSD
Last edited by Shaggy Sheep Driver; 21st July 2006 at 10:31.
Joined: Apr 2003
Posts: 2,359
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From: Midlands
AoA devices are becoming popular in permit machines. For example, an MCR01 has to have a stall warning or AoA device fitted. I had a ride in one which talked to you via the intercom, but it did seem a bit OTT to me.
Rod1
Rod1
Joined: Oct 2005
Posts: 913
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From: somewhere in Oz
Thinking AoA is all well and good, but relative to what? It needs to be airflow, but the brain doesn't sense that too well without reference to a gauge. All it sees is attitude and that doesn't take into consideration the vertical airspeed, which whilst decending increases the AoA relative to the 'conventionally percieved' AoA (i.e. attitude) This is possibly why stall/spin accidents on turning final are not as rare as they should be.
When I was practicing PFL's I was surprised initially that I felt like I had to dive at the ground when rolling on bank for a turn in order to maintain airspeed. IMHO, the reasons behind this were not adequately explained/reinforced in my training and hence it was something I 'learnt by experience' rather than was expecting to see and experience from theory.
A
When I was practicing PFL's I was surprised initially that I felt like I had to dive at the ground when rolling on bank for a turn in order to maintain airspeed. IMHO, the reasons behind this were not adequately explained/reinforced in my training and hence it was something I 'learnt by experience' rather than was expecting to see and experience from theory.
A
