8 minutes ago, FDEdev said:

 

Murmur already wrote:  It is true, as you say, that the AoA is not an indicator of vertical speed. But nobody ever stated that.

Btw, I'm out.

 

Okay, not once did I say that anyone said AoA is an indicator of vertical speed. Just that to state the AoA indicator gives ACCURATE feedback re updrafts and downdrafts is, in my opinion, wrong.

 

It cant do so because it is feasible for updrafts and downdrafts to occur with out the aircrafts velocity changing and thus, without angle of attack changing. Furthermore,  you wouldnt know if that indication on the AoA was just as a result of speed change.

 

So how is the above ACCURATE feedback.

47 minutes ago, FDEdev said:

It's very difficult to stay polite if you are so stubborn and continue your completely wrong claims over and over again. You are disregarding everything w6kd, Murmur and I explained to you. 
What do you expect? 

 

Actually, it's very easy to stay polite. And what I EXPECT is maturity, manners, generally being nice. The reason I'm disregarding what you say to me is easy, its calad disagreeing. 

I will stop disagreeing with points made when I'm convinced. Sorry but I'm not just going to agree with you just to make you happy.

 

It's something we have to accept, that in life others will disagree.

I note, you were tetchy in your very first response.

Edited March 4, 20206 yr by martin-w

5 hours ago, eslader said:

I think if you guys reframe the picture of what is moving, it might clear things up for everyone. Instead of thinking of the plane flying through the air, think of the air moving past the plane.

 

If you're flying straight and level at 100kts on a completely calm day, it's the same thing as the plane being completely still while a 100 knot wind flows from nose to tail.

If the wind changes such that there is an updraft or downdraft in addition to the 100kt horizontal component, then it is no longer a 100 knot wind flowing directly from nose to tail. The vector of the air's velocity has changed - it's either going up or down at an angle rather than straight at the plane.

As it hits the wing, the angle of attack *is* different, even if the plane doesn't climb or descend.

Remember that AOA involves the *relative* wind as measured against the chord of the wing, not the absolute wind.

 

 

A better explanation. And unlike some, politely put too.

What I may have been neglecting is the forward speed. That, plus an up or downdraft even if from directly above, directs the velocity vector somewhat down or up. Hence change in angle of attack.

In fact theres a second factor to consider. In a downdraft the tail drops. In an updraft the tail rises.

 

If I was a better writer, I would soften this up.  As I mean no disrespect, and just want to help.  So hopefully I don't add to the flared tempers in this thread.

  

1 hour ago, martin-w said:

Okay, not once did I say that anyone said AoA is an indicator of vertical speed.

"The premise was that AoA indicator is an accurate indication of vertical speed." - martin-w

1 hour ago, martin-w said:

Just that to state the AoA indicator gives ACCURATE feedback re updrafts and downdrafts is, in my opinion, wrong.

I checked this thread, and you are the only one that has used the word "accurate".  I may have missed a synonym though.  I have never used a AoA in real life.  But I think people are just saying it can indicate a updraft or downdraft .  It is up to the pilot to interpret the display.

 

1 hour ago, martin-w said:

It cant do so because it is feasible for updrafts and downdrafts to occur with out the aircrafts velocity changing and thus, without angle of attack changing.  Furthermore,  you wouldnt know if that indication on the AoA was just as a result of speed change.

I don't see the connection.  If you mount the plane on a pedestal, so "velocity" doesn't change, you can then blow wind on it from different angles to the wings.  So AoA changes, but velocity doesn't.  If this doesn't help, can you give a simple example?

 

OK, we've reached the point of pointlessness here.  Locked.