Thinking about stalls

[WingFlaps]

Hi All,

Imagine a plane in 2 conditions.

1) Climbing with full power
2) Descending fast with 50% power.

Both have constant rates of ascent and descent.

Question A: Which wing is closer to stall?
Question B: A big updraft occurs, which is more likely to stall?

If you vote first it _may_ lead to some good discussion later...

Cheers

[Jim Logajan]

WingFlaps > wrote:
> Hi All,
>
> Imagine a plane in 2 conditions.
>
> 1) Climbing with full power
> 2) Descending fast with 50% power.

Waitaminute - how can a plane be in both conditions at the same time!?

> Both have constant rates of ascent and descent.

But are they the same rates or different?
What are the angles of attack on the wings in both cases?
What are the indicated airspeeds - the same or different?

> Question A: Which wing is closer to stall?

The left one. I think. Except if it's a biplane and Tuesday, in which case
it would be the red one.

> Question B: A big updraft occurs, which is more likely to stall?

The one whose condition was closer to stall.
;-)

[WingFlaps]

On Mar 13, 1:41*pm, Jim Logajan > wrote:
> WingFlaps > wrote:
> > Hi All,
>
> > Imagine a plane in 2 conditions.
>
> > 1) Climbing with full power
> > 2) Descending fast with 50% power.
>
> Waitaminute - how can a plane be in both conditions at the same time!?
>
> > Both have constant rates of ascent and descent.
>
> But are they the same rates or different?
> What are the angles of attack on the wings in both cases?
> What are the indicated airspeeds - the same or different?
>
> > Question A: Which wing is closer to stall?
>
> The left one. I think. Except if it's a biplane and Tuesday, in which case
> it would be the red one.
>
> > Question B: A big updraft occurs, which is more likely to stall?
>
> The one whose condition was closer to stall.
> ;-)

Aha, too deep for you eh? :-P

Cheers

[Jim Logajan]

WingFlaps > wrote:
> On Mar 13, 1:41*pm, Jim Logajan > wrote:
>> WingFlaps > wrote:
>> > Hi All,
>>
>> > Imagine a plane in 2 conditions.
>>
>> > 1) Climbing with full power
>> > 2) Descending fast with 50% power.
>>
>> Waitaminute - how can a plane be in both conditions at the same
>> time!?
>>
>> > Both have constant rates of ascent and descent.
>>
>> But are they the same rates or different?
>> What are the angles of attack on the wings in both cases?
>> What are the indicated airspeeds - the same or different?
>>
>> > Question A: Which wing is closer to stall?
>>
>> The left one. I think. Except if it's a biplane and Tuesday, in which
>> case
>
>> it would be the red one.
>>
>> > Question B: A big updraft occurs, which is more likely to stall?
>>
>> The one whose condition was closer to stall.
>> ;-)
>
> Aha, too deep for you eh? :-P

Much too deep. But if you want a straight answer, I'd say a climbing plane
would be more likely to stall if a big updraft occurs. The plane's inertia
comes into play and causes the airflow to slow up over the wings (maybe
even reversing direction!?) coupled with the pilot's Hawaiian shirt all
conspire to cause the lift demons to depart. I least I think so.

[WingFlaps]

On Mar 13, 3:13*pm, Jim Logajan > wrote:
> WingFlaps > wrote:
> > On Mar 13, 1:41*pm, Jim Logajan > wrote:
> >> WingFlaps > wrote:
> >> > Hi All,
>
> >> > Imagine a plane in 2 conditions.
>
> >> > 1) Climbing with full power
> >> > 2) Descending fast with 50% power.
>
> >> Waitaminute - how can a plane be in both conditions at the same
> >> time!?
>
> >> > Both have constant rates of ascent and descent.
>
> >> But are they the same rates or different?
> >> What are the angles of attack on the wings in both cases?
> >> What are the indicated airspeeds - the same or different?
>
> >> > Question A: Which wing is closer to stall?
>
> >> The left one. I think. Except if it's a biplane and Tuesday, in which
> >> case
>
> >> it would be the red one.
>
> >> > Question B: A big updraft occurs, which is more likely to stall?
>
> >> The one whose condition was closer to stall.
> >> ;-)
>
> > Aha, too deep for you eh? *:-P
>
> Much too deep. But if you want a straight answer, I'd say a climbing plane
> would be more likely to stall if a big updraft occurs. The plane's inertia
> comes into play and causes the airflow to slow up over the wings (maybe
> even reversing direction!?) coupled with the pilot's Hawaiian shirt all
> conspire to cause the lift demons to depart. I least I think so.- Hide quoted text -
>

So, 1 vote for B1 and what about question A?

Cheers

[Jim Logajan]

WingFlaps > wrote:
>> >> > Imagine a plane in 2 conditions.
>>
>> >> > 1) Climbing with full power
>> >> > 2) Descending fast with 50% power.
>> >> > Question A: Which wing is closer to stall?
>
> So, 1 vote for B1 and what about question A?

I don't know. Maybe the angle of attack on the wings can be determined by
the information you provide for both conditions, but if so it is beyond my
limited capabilities. As it stands, I'm inclined to say you aren't
providing enough information to make an informed decision.

[[email protected]]

On Mar 12, 5:14 pm, WingFlaps > wrote:
> Hi All,
>
> Imagine a plane in 2 conditions.
>
> 1) Climbing with full power
> 2) Descending fast with 50% power.
>
> Both have constant rates of ascent and descent.
>
> Question A: Which wing is closer to stall?
> Question B: A big updraft occurs, which is more likely to stall?
>
> If you vote first it _may_ lead to some good discussion later...
>
> Cheers

The aircraft in climb will have the lower airspeed and therefore
the higher AOA. Lower airspeed means higher AOA to lift the same
weight. A cruising descent is a high airspeed, so AOA is much lower.
Both will be in a 1 G condition.
An updraft increases AOA, so the climbing airplane is closer to
stall. A cruising descent in the yellow arc, OTOH, might get the wings
torn off in a "big" updraft. Stall doesn't matter anymore.

Dan

[Phil J]

On Mar 12, 7:14*pm, WingFlaps > wrote:
> Hi All,
>
> Imagine a plane in 2 conditions.
>
> 1) Climbing with full power
> 2) Descending fast with 50% power.
>
> Both have constant rates of ascent and descent.
>
> Question A: Which wing is closer to stall?
> Question B: A big updraft occurs, which is more likely to stall?
>
> If you vote first it _may_ lead to some good discussion later...
>
> Cheers

It would depend on the angle of attack. You could be in a very
shallow climb at full power, and have lots of margin above the stall.
On the other hand, you could be descending at 50% power in a very nose-
high attitude, and have very little margin above the stall. Plus,
there's the cost of the hamburger you are flying towards.

Phil

[WingFlaps]

On Mar 13, 3:41*pm, wrote:
> On Mar 12, 5:14 pm, WingFlaps > wrote:
>
> > Hi All,
>
> > Imagine a plane in 2 conditions.
>
> > 1) Climbing with full power
> > 2) Descending fast with 50% power.
>
> > Both have constant rates of ascent and descent.
>
> > Question A: Which wing is closer to stall?
> > Question B: A big updraft occurs, which is more likely to stall?
>
> > If you vote first it _may_ lead to some good discussion later...
>
> > Cheers
>
> * * * The aircraft in climb will have the lower airspeed and therefore
> the higher AOA. Lower airspeed means higher AOA to lift the same
> weight. A cruising descent is a high airspeed, so AOA is much lower.
> Both will be in a 1 G condition.

OK... but is the climbing or descending wing generating the most
lift?

> * * * An updraft increases AOA, so the climbing airplane is closer to
> stall. A cruising descent in the yellow arc, OTOH, might get the wings
> torn off in a "big" updraft. Stall doesn't matter anymore.
>

Cheers

[Big John]

On Wed, 12 Mar 2008 17:14:17 -0700 (PDT), WingFlaps
> wrote:

>Hi All,
>
>Imagine a plane in 2 conditions.
>
>1) Climbing with full power
>2) Descending fast with 50% power.
>
>Both have constant rates of ascent and descent.
>
>Question A: Which wing is closer to stall?
>Question B: A big updraft occurs, which is more likely to stall?
>
>If you vote first it _may_ lead to some good discussion later...
>
>Cheers

***************************************
Obviously #2. Any one should be able to see that.

Big John

[WingFlaps]

On Mar 13, 6:45*pm, Big John > wrote:
> On Wed, 12 Mar 2008 17:14:17 -0700 (PDT), WingFlaps
>
>
>
>
>
> > wrote:
> >Hi All,
>
> >Imagine a plane in 2 conditions.
>
> >1) Climbing with full power
> >2) Descending fast with 50% power.
>
> >Both have constant rates of ascent and descent.
>
> >Question A: Which wing is closer to stall?
> >Question B: A big updraft occurs, which is more likely to stall?
>
> >If you vote first it _may_ lead to some good discussion later...
>
> >Cheers
>
> ***************************************
> Obviously #2. Any one should be able to see that.
>

Aha, so it is closer to the stall?

Cheers

[Bertie the Bunyip[_24_]]

Jim Logajan > wrote in
:

> WingFlaps > wrote:
>> Hi All,
>>
>> Imagine a plane in 2 conditions.
>>
>> 1) Climbing with full power
>> 2) Descending fast with 50% power.
>
> Waitaminute - how can a plane be in both conditions at the same time!?
>

Ken can probably explain it better than anyone.


Bertie

[gatt[_2_]]

"WingFlaps" > wrote in message
...
> Hi All,
>
> Imagine a plane in 2 conditions.
>
> 1) Climbing with full power
> 2) Descending fast with 50% power.
>
> Both have constant rates of ascent and descent.
>
> Question A: Which wing is closer to stall?
> Question B: A big updraft occurs, which is more likely to stall?


I'm not sure if there's enough information. If it's a typical prop plant I
would expect that there would be a difference between a high wing and a low
wing due to slipstream effects, but my guess would be that the right wing
would be closer. Or, are you asking which of the two scenarios is
closer/more likely to stall. In that case, I'd say the first
configuration. Full-power departure stalls are easy to encounter.

-c

[TakeFlight]

Put me in the "not enough info" column.

Plane #2 could be in fact _in_ a stall (or spin), "descending fast
with 50% power" or _more_. Think Delta Flight 191, for example.



On Mar 12, 8:14 pm, WingFlaps > wrote:
> Hi All,
>
> Imagine a plane in 2 conditions.
>
> 1) Climbing with full power
> 2) Descending fast with 50% power.
>
> Both have constant rates of ascent and descent.
>
> Question A: Which wing is closer to stall?
> Question B: A big updraft occurs, which is more likely to stall?
>
> If you vote first it _may_ lead to some good discussion later...
>
> Cheers

[Brian[_1_]]

> OK... *but is the climbing or descending wing generating the most
> lift?
>
I agree, your original question is missing some critical information.
Such as:

1. are the airspeeds the same for each aircraft?
2. confirm that the decending aircraft is not already stalled
3. Do the airplanes weigh the same?


As for your question above, given that the airplanes are ascending or
decending at constant rates then the lift is equal to the wieght of
the airplane in both cases. If the aircraft are the same wieght then
the lift generated will be the same.

Brian CFIIG/ASEL

[WingFlaps]

On Mar 14, 9:11*am, Brian > wrote:

>
> As for your question above, given that the airplanes are ascending or
> decending at constant rates then the lift is equal to the wieght of
> the airplane in both cases. If the aircraft are the same wieght then
> the lift generated will be the same.
>

That is not correct.

Cheers

[WingFlaps]

On Mar 14, 4:02*am, "gatt" > wrote:
> "WingFlaps" > wrote in message
>
> ...
>
> > Hi All,
>
> > Imagine a plane in 2 conditions.
>
> > 1) Climbing with full power
> > 2) Descending fast with 50% power.
>
> > Both have constant rates of ascent and descent.
>
> > Question A: Which wing is closer to stall?
> > Question B: A big updraft occurs, which is more likely to stall?
>
> I'm not sure if there's enough information. *If it's a typical prop plant I
> would expect that there would be a difference between a high wing and a low
> wing due to slipstream effects, but my guess would be that the right wing
> would be closer. * Or, are you asking which of the two scenarios is
> closer/more likely to stall. * *In that case, I'd say the first
> configuration. * *Full-power departure stalls are easy to encounter.
>

Ok good, but let's say both planes have the same airspeed. Does that
change anything?
Cheers

[Jim Logajan]

WingFlaps > wrote:
> On Mar 14, 9:11*am, Brian > wrote:
>> As for your question above, given that the airplanes are ascending or
>> decending at constant rates then the lift is equal to the wieght of
>> the airplane in both cases. If the aircraft are the same wieght then
>> the lift generated will be the same.
>>
>
> That is not correct.

Hmmm. Brian's statement appears essentially correct - and you are correct
too. The "gotcha" is that the vertical component of the lift force exceeds
the weight only during the transition from level flight to constant
ascending flight. And the lift force is less than the weight during the
transition from level flight to constant descending flight.

But once the vertical speed becomes constant (whether up or down) the
vertical component of lift has to equal the downward force of gravity. If
it didn't, then the aircraft would begin _accelerating_ up or down,
depending on the difference.

[WingFlaps]

On Mar 14, 9:33*am, Jim Logajan > wrote:
> WingFlaps > wrote:
> > On Mar 14, 9:11*am, Brian > wrote:
> >> As for your question above, given that the airplanes are ascending or
> >> decending at constant rates then the lift is equal to the wieght of
> >> the airplane in both cases. If the aircraft are the same wieght then
> >> the lift generated will be the same.
>
> > That is not correct.
>
> Hmmm. Brian's statement appears essentially correct - and you are correct
> too. The "gotcha" is that the vertical component of the lift force exceeds
> the weight only during the transition from level flight to constant
> ascending flight. And the lift force is less than the weight during the
> transition from level flight to constant descending flight.
>
> But once the vertical speed becomes constant (whether up or down) the
> vertical component of lift has to equal the downward force of gravity. If
> it didn't, then the aircraft would begin _accelerating_ up or down,
> depending on the difference.

Nope, if the airspeed is constant, the lift from the two wings is not
the same. This is thought provoking discussion I was hoping to start!
Can you see why lift does not equal weight in both cases?

Cheers

[Jim Logajan]

WingFlaps > wrote:
> On Mar 14, 9:33*am, Jim Logajan > wrote:
>> WingFlaps > wrote:
>> > On Mar 14, 9:11*am, Brian > wrote:
>> >> As for your question above, given that the airplanes are ascending
>> >> or decending at constant rates then the lift is equal to the
>> >> wieght of the airplane in both cases. If the aircraft are the same
>> >> wieght then the lift generated will be the same.
>>
>> > That is not correct.
>>
>> Hmmm. Brian's statement appears essentially correct - and you are
>> correct too. The "gotcha" is that the vertical component of the lift
>> force exceeds
>
>> the weight only during the transition from level flight to constant
>> ascending flight. And the lift force is less than the weight during
>> the transition from level flight to constant descending flight.
>>
>> But once the vertical speed becomes constant (whether up or down) the
>> vertical component of lift has to equal the downward force of
>> gravity. If it didn't, then the aircraft would begin _accelerating_
>> up or down, depending on the difference.
>
> Nope, if the airspeed is constant, the lift from the two wings is not
> the same. This is thought provoking discussion I was hoping to start!
> Can you see why lift does not equal weight in both cases?

I don't wish to be confrontational since you are looking for thought
provoking discussion, but I am pretty sure there is a fair amount of
imprecision, and therefore ambiguity, in your statements. This tends to
make it difficult to get very far in these discussions.

Would it help any if I presented the 2-D equations of force involved?
And perhaps you could do the same?

[[email protected]]

On Mar 13, 1:37 pm, WingFlaps > wrote:

> Nope, if the airspeed is constant, the lift from the two wings is not
> the same. This is thought provoking discussion I was hoping to start!
> Can you see why lift does not equal weight in both cases?

Common misconception: that a climbing wing is generating more
lift than a descending wing. If the flight paths are both straight
lines, whether climbing or descending, the lift is the same in both
cases. As Jim said, only a change in the direction of flight will
change the lift/weight ratio. A G-meter (such as in our Citabrias)
will prove it.
If the airspeeds are the same and the flight paths are both
straight, the AOAs are both the same, too. But change the speeds while
leaving the flight paths alone, and the AOA will change. It's why the
airplane has a nose-high attitude in level slow flight as opposed to a
lower nose attitude in level cruise.

Dan

[WingFlaps]

On Mar 14, 9:59*am, Jim Logajan > wrote:
> WingFlaps > wrote:
> > On Mar 14, 9:33*am, Jim Logajan > wrote:
> >> WingFlaps > wrote:
> >> > On Mar 14, 9:11*am, Brian > wrote:
> >> >> As for your question above, given that the airplanes are ascending
> >> >> or decending at constant rates then the lift is equal to the
> >> >> wieght of the airplane in both cases. If the aircraft are the same
> >> >> wieght then the lift generated will be the same.
>
> >> > That is not correct.
>
> >> Hmmm. Brian's statement appears essentially correct - and you are
> >> correct too. The "gotcha" is that the vertical component of the lift
> >> force exceeds
>
> >> the weight only during the transition from level flight to constant
> >> ascending flight. And the lift force is less than the weight during
> >> the transition from level flight to constant descending flight.
>
> >> But once the vertical speed becomes constant (whether up or down) the
> >> vertical component of lift has to equal the downward force of
> >> gravity. If it didn't, then the aircraft would begin _accelerating_
> >> up or down, depending on the difference.
>
> > Nope, if the airspeed is constant, the lift from the two wings is not
> > the same. This is thought provoking discussion I was hoping to start!
> > Can you see why lift does not equal weight in both cases?
>
> I don't wish to be confrontational since you are looking for thought
> provoking discussion, but I am pretty sure there is a fair amount of
> imprecision, and therefore ambiguity, in your statements. This tends to
> make it difficult to get very far in these discussions.
>
> Would it help any if I presented the 2-D equations of force involved?
> And perhaps you could do the same?- Hide quoted text -
>

Sure here you go:
D=drag
L=lift
W=weight
T=thrust
alpha=angle of thrust

For no acceleration in any plane:

W=Tsin(alpha) + L
D=Tcos(alpha)

What you and many other texts have missed is that the thrust angle
changes...
What this means is that when you make a plane climb at constant speed
you are deliberately reducing lift from from the wing and supplanting
it with engine thrust! To extend this idea further, it is not the
climb per se that may be the problem but a decaying airspeed... The
above equations can be extended to the AOA and airspeed but the
conclusion remains the same.

Now, what about that tricky updraft? Is this thought provoking :-)

Cheers

[WingFlaps]

On Mar 14, 1:00*pm, wrote:
> On Mar 13, 1:37 pm, WingFlaps > wrote:
>
> > Nope, if the airspeed is constant, the lift from the two wings is not
> > the same. This is thought provoking discussion I was hoping to start!
> > Can you see why lift does not equal weight in both cases?
>
> * * * Common misconception: that a climbing wing is generating more
> lift than a descending wing. If the flight paths are both straight
> lines, whether *climbing or descending, the lift is the same in both
> cases. As Jim said, only a change in the direction of flight will
> change the lift/weight ratio. A G-meter (such as in our Citabrias)
> will prove it.
> * * * If the airspeeds are the same and the flight paths are both
> straight, the AOAs are both the same, too. But change the speeds while
> leaving the flight paths alone, and the AOA will change. It's why the
> airplane has a nose-high attitude in level slow flight as opposed to a
> lower nose attitude in level cruise.
>

Hi Dan see my rely to Jim. In fact, lift is reduced in a steady climb.

Cheers

[Dan[_10_]]

On Mar 13, 8:50 pm, WingFlaps > wrote:
> On Mar 14, 1:00 pm, wrote:
>
>
>
> > On Mar 13, 1:37 pm, WingFlaps > wrote:
>
> > > Nope, if the airspeed is constant, the lift from the two wings is not
> > > the same. This is thought provoking discussion I was hoping to start!
> > > Can you see why lift does not equal weight in both cases?
>
> > Common misconception: that a climbing wing is generating more
> > lift than a descending wing. If the flight paths are both straight
> > lines, whether climbing or descending, the lift is the same in both
> > cases. As Jim said, only a change in the direction of flight will
> > change the lift/weight ratio. A G-meter (such as in our Citabrias)
> > will prove it.
> > If the airspeeds are the same and the flight paths are both
> > straight, the AOAs are both the same, too. But change the speeds while
> > leaving the flight paths alone, and the AOA will change. It's why the
> > airplane has a nose-high attitude in level slow flight as opposed to a
> > lower nose attitude in level cruise.
>
> Hi Dan see my rely to Jim. In fact, lift is reduced in a steady climb.
>
> Cheers

The trust vector is added to the lift vector in a climb, as the drag
is added to weight.

Dan Mc

[WingFlaps]

On Mar 14, 2:46*pm, Dan > wrote:
> On Mar 13, 8:50 pm, WingFlaps > wrote:
>
>
>
>
>
> > On Mar 14, 1:00 pm, wrote:
>
> > > On Mar 13, 1:37 pm, WingFlaps > wrote:
>
> > > > Nope, if the airspeed is constant, the lift from the two wings is not
> > > > the same. This is thought provoking discussion I was hoping to start!
> > > > Can you see why lift does not equal weight in both cases?
>
> > > * * * Common misconception: that a climbing wing is generating more
> > > lift than a descending wing. If the flight paths are both straight
> > > lines, whether *climbing or descending, the lift is the same in both
> > > cases. As Jim said, only a change in the direction of flight will
> > > change the lift/weight ratio. A G-meter (such as in our Citabrias)
> > > will prove it.
> > > * * * If the airspeeds are the same and the flight paths are both
> > > straight, the AOAs are both the same, too. But change the speeds while
> > > leaving the flight paths alone, and the AOA will change. It's why the
> > > airplane has a nose-high attitude in level slow flight as opposed to a
> > > lower nose attitude in level cruise.
>
> > Hi Dan see my rely to Jim. In fact, lift is reduced in a steady climb.
>
> > Cheers
>
> The trust vector is added to the lift vector in a climb, as the drag
> is added to weight.
>

Are you saying that wing lift does not change with attitude in a non-
accelerating frame?

Cheers

[Dan[_10_]]

On Mar 13, 9:57 pm, WingFlaps > wrote:
> On Mar 14, 2:46 pm, Dan > wrote:
>
>
>
> > On Mar 13, 8:50 pm, WingFlaps > wrote:
>
> > > On Mar 14, 1:00 pm, wrote:
>
> > > > On Mar 13, 1:37 pm, WingFlaps > wrote:
>
> > > > > Nope, if the airspeed is constant, the lift from the two wings is not
> > > > > the same. This is thought provoking discussion I was hoping to start!
> > > > > Can you see why lift does not equal weight in both cases?
>
> > > > Common misconception: that a climbing wing is generating more
> > > > lift than a descending wing. If the flight paths are both straight
> > > > lines, whether climbing or descending, the lift is the same in both
> > > > cases. As Jim said, only a change in the direction of flight will
> > > > change the lift/weight ratio. A G-meter (such as in our Citabrias)
> > > > will prove it.
> > > > If the airspeeds are the same and the flight paths are both
> > > > straight, the AOAs are both the same, too. But change the speeds while
> > > > leaving the flight paths alone, and the AOA will change. It's why the
> > > > airplane has a nose-high attitude in level slow flight as opposed to a
> > > > lower nose attitude in level cruise.
>
> > > Hi Dan see my rely to Jim. In fact, lift is reduced in a steady climb.
>
> > > Cheers
>
> > The trust vector is added to the lift vector in a climb, as the drag
> > is added to weight.
>
> Are you saying that wing lift does not change with attitude in a non-
> accelerating frame?
>
> Cheers

Of course it does.

However -- In a climb thrust acts contrary to drag some component of
weight (depending on the angle of climb). Thus the angle of attack is
not *necessarily* equal to the angle of climb.


Dan Mc

[WingFlaps]

On Mar 15, 12:08 am, Dan > wrote:
> On Mar 13, 9:57 pm, WingFlaps > wrote:
>
>
>
>
>
> > On Mar 14, 2:46 pm, Dan > wrote:
>
> > > On Mar 13, 8:50 pm, WingFlaps > wrote:
>
> > > > On Mar 14, 1:00 pm, wrote:
>
> > > > > On Mar 13, 1:37 pm, WingFlaps > wrote:
>
> > > > > > Nope, if the airspeed is constant, the lift from the two wings is not
> > > > > > the same. This is thought provoking discussion I was hoping to start!
> > > > > > Can you see why lift does not equal weight in both cases?
>
> > > > > Common misconception: that a climbing wing is generating more
> > > > > lift than a descending wing. If the flight paths are both straight
> > > > > lines, whether climbing or descending, the lift is the same in both
> > > > > cases. As Jim said, only a change in the direction of flight will
> > > > > change the lift/weight ratio. A G-meter (such as in our Citabrias)
> > > > > will prove it.
> > > > > If the airspeeds are the same and the flight paths are both
> > > > > straight, the AOAs are both the same, too. But change the speeds while
> > > > > leaving the flight paths alone, and the AOA will change. It's why the
> > > > > airplane has a nose-high attitude in level slow flight as opposed to a
> > > > > lower nose attitude in level cruise.
>
> > > > Hi Dan see my rely to Jim. In fact, lift is reduced in a steady climb.
>
> > > > Cheers
>
> > > The trust vector is added to the lift vector in a climb, as the drag
> > > is added to weight.
>
> > Are you saying that wing lift does not change with attitude in a non-
> > accelerating frame?
>
> > Cheers
>
> Of course it does.
>
> However -- In a climb thrust acts contrary to drag some component of
> weight (depending on the angle of climb). Thus the angle of attack is
> not *necessarily* equal to the angle of climb.
>
I'm sorry but I'm having trouble understanding where you are coming
from. In my equations above I wrote that D=Tcos(alpha) and this is
based on the idea that W,D and L are 3 orthogonal forces. Of course
you can rewrite them non orthogonally if you please but my expression
makes good sense (to me anyway). This is why: Imagine a jet in a
steady vertical climb (alpha=90 degrees). My equation says D=0 so how
can that be? The answer is that this simplified (wing + engine) model
is really only considering induced drag and that the thrust line is
close to 0 AOA (not bad approximations IMHO). For induced drag to be
zero, wing LIFT _must_ be zero and so we see that Weight =Tsin(90) + L
-> W=T -exactly as it should be for a vertical climb! The pilot has
reduced AOA to zero, the wing produces NO lift and the plane climbs
vertically. Again, I say L should be dropped to zero for a true steady
vertical climb and L=W only in straight and level flight or if the
plane is gliding (T=0). In all steady climbs L<W and all descents L>W.

I was a bit surprised when I realized that to be in a steady climb
the pilot must be operating the plane in a condition where wing lift
and AOA are actually lower than in straight and level -all thanks to
a component of thrust adding to lift !!! Although the effect may not
be large for low power planes (T<<W) , if what I'm saying makes sense,
one may see some advantages in this approach -e.g. why increasing
power leads to a nice steady climb or cutting power causes the nose to
drop and a descent to begin...

Cheers

[Bertie the Bunyip[_24_]]

TakeFlight > wrote in news:935d6394-8224-482e-9428-
:

> Put me in the "not enough info" column.
>
> Plane #2 could be in fact _in_ a stall (or spin), "descending fast
> with 50% power" or _more_. Think Delta Flight 191, for example.


That was something else entirely. That was a microburst. The rules pretty
much go out the window with one of those.
not to say the laws of physics are suspended, but it's a scenario that is
so different from what we learn as pilots that drastic retraining was
introduced right across the board after it. Flight guidance systems were
modified to account for the new methods, so it's not really relevant.

Just to give you some idea of what I mean, I'll give you a scenario. You've
just aken off and yoou're climibing away at best rate. Suddenly, your
airspeed increases by a fairly large lump. 15-20 knots, say. you increase
your pitcha bit to absorb it and your speed bleeds back a tad. Still plenty
in hand, though. all the sudden the pitch you have is dragging your speed
back and it's beginning to decrease as the wind that delivered that extra
speed vanishes. You're still OK and back to your orignal pitch and have a
couple of knots more than you had at the beginning. All the sudden, the
bottom falls out of your airplane. Your climb stops and then a second later
you begin to sink, and fast. another second or two and your speed washes
off even further and now you're sinkng and your stall warning is starting
to squeak.

you gotta do something and right now. you still have some altitude, say 400
feet. what do you do?



Bertie

[[email protected]]

On Mar 14, 11:37*am, Bertie the Bunyip > wrote:
> TakeFlight > wrote in news:935d6394-8224-482e-9428-
> :
>
> > Put me in the "not enough info" column.
>
> > Plane #2 could be in fact _in_ a stall (or spin), "descending fast
> > with 50% power" or _more_. *Think Delta Flight 191, for example.
>
> That was something else entirely. That was a microburst. The rules pretty
> much go out the window with one of those.
> not to say the laws of physics are suspended, but it's a scenario that is
> so different from what we learn as pilots that drastic retraining was *
> introduced right across the board after it. Flight guidance systems were
> modified to account for the new methods, so it's not really relevant.
>
> Just to give you some idea of what I mean, I'll give you a scenario. You've
> just aken off and yoou're climibing away at best rate. Suddenly, your
> airspeed increases by a fairly large lump. 15-20 knots, say. you increase
> your pitcha bit to absorb it and your speed bleeds back a tad. Still plenty
> in hand, though. all the sudden the pitch you have is dragging your speed
> back and it's beginning to decrease as the wind that delivered that extra
> speed vanishes. You're still OK and back to your orignal pitch and have a
> couple of knots more than you had at the beginning. All the sudden, the
> bottom falls out of your airplane. Your climb stops and then a second later *
> you begin to sink, and fast. another second or two and your speed washes
> off even further and now you're sinkng and your stall warning is starting
> to squeak.
>
> you gotta do something and right now. you still have some altitude, say 400
> feet. what do you do?
>
> Bertie

Alt-Ctl-Del

No, wait, change my underwear.

Yoke forward, nose down and max power?

Richard

[Bertie the Bunyip[_24_]]

wrote in
:

> On Mar 14, 11:37*am, Bertie the Bunyip > wrote:
>> TakeFlight > wrote in
>> news:935d6394-8224-482e-9428-
>> :
>>
>> > Put me in the "not enough info" column.
>>
>> > Plane #2 could be in fact _in_ a stall (or spin), "descending fast
>> > with 50% power" or _more_. *Think Delta Flight 191, for example.
>>
>> That was something else entirely. That was a microburst. The rules
>> pretty much go out the window with one of those.
>> not to say the laws of physics are suspended, but it's a scenario
>> that is so different from what we learn as pilots that drastic
>> retraining was * introduced right across the board after it. Flight
>> guidance systems were modified to account for the new methods, so
>> it's not really relevant.
>>
>> Just to give you some idea of what I mean, I'll give you a scenario.
>> You'v
> e
>> just aken off and yoou're climibing away at best rate. Suddenly, your
>> airspeed increases by a fairly large lump. 15-20 knots, say. you
>> increase your pitcha bit to absorb it and your speed bleeds back a
>> tad. Still plent
> y
>> in hand, though. all the sudden the pitch you have is dragging your
>> speed back and it's beginning to decrease as the wind that delivered
>> that extra speed vanishes. You're still OK and back to your orignal
>> pitch and have a couple of knots more than you had at the beginning.
>> All the sudden, the bottom falls out of your airplane. Your climb
>> stops and then a second late
> r *
>> you begin to sink, and fast. another second or two and your speed
>> washes off even further and now you're sinkng and your stall warning
>> is starting to squeak.
>>
>> you gotta do something and right now. you still have some altitude,
>> say 40
> 0
>> feet. what do you do?
>>
>> Bertie
>
> Alt-Ctl-Del
>
> No, wait, change my underwear.
>
> Yoke forward, nose down and max power?

That's what the Delta guys did. And that 727 in New Orleans. A different
approach was needed and what they came up with was full power. and in a
jet that means firewall and overboost to your little heart's contenet,
and nose up as much as you can. The stall warnign should be ringing off
the wall ( we have stick shakers, but same thing) and you keep this up
til you fly out the other side of the mess. It goes against everything
we've learned but that's what they tell us to do. There's generally some
guidance form the flight director as well. On some it's a set of yellow
"antlers" that give you best pitch and on others the pitch bar on the
flight director just gives you all the pitch info you need ( you just
put the airplane wings on a magenta bar, no brains required)
note this is for a sustained and powerful microburst and not for
recovery form a tiny bit of wind shear in a 20 knot wind.

Bertie

[[email protected]]

On Mar 14, 11:58*am, Bertie the Bunyip > wrote:
> wrote :
>
>
>
> > On Mar 14, 11:37*am, Bertie the Bunyip > wrote:
> >> TakeFlight > wrote in
> >> news:935d6394-8224-482e-9428-
> >> :
>
> >> > Put me in the "not enough info" column.
>
> >> > Plane #2 could be in fact _in_ a stall (or spin), "descending fast
> >> > with 50% power" or _more_. *Think Delta Flight 191, for example.
>
> >> That was something else entirely. That was a microburst. The rules
> >> pretty much go out the window with one of those.
> >> not to say the laws of physics are suspended, but it's a scenario
> >> that is so different from what we learn as pilots that drastic
> >> retraining was * introduced right across the board after it. Flight
> >> guidance systems were modified to account for the new methods, so
> >> it's not really relevant.
>
> >> Just to give you some idea of what I mean, I'll give you a scenario.
> >> You'v
> > e
> >> just aken off and yoou're climibing away at best rate. Suddenly, your
> >> airspeed increases by a fairly large lump. 15-20 knots, say. you
> >> increase your pitcha bit to absorb it and your speed bleeds back a
> >> tad. Still plent
> > y
> >> in hand, though. all the sudden the pitch you have is dragging your
> >> speed back and it's beginning to decrease as the wind that delivered
> >> that extra speed vanishes. You're still OK and back to your orignal
> >> pitch and have a couple of knots more than you had at the beginning.
> >> All the sudden, the bottom falls out of your airplane. Your climb
> >> stops and then a second late
> > r *
> >> you begin to sink, and fast. another second or two and your speed
> >> washes off even further and now you're sinkng and your stall warning
> >> is starting to squeak.
>
> >> you gotta do something and right now. you still have some altitude,
> >> say 40
> > 0
> >> feet. what do you do?
>
> >> Bertie
>
> > Alt-Ctl-Del
>
> > No, wait, change my underwear.
>
> > Yoke forward, nose down and max power?
>
> That's what the Delta guys did. And that 727 in New Orleans. A different
> approach was needed and what they came up with was full power. and in a
> jet that means firewall and overboost to your little heart's contenet,
> and nose up as much as you can. The stall warnign should be ringing off
> the wall ( we have stick shakers, but same thing) and you keep this up
> til you fly out the other side of the mess. It goes against everything
> we've learned but that's what they tell us to do. There's generally some
> guidance form the flight director as well. On some it's a set of yellow
> "antlers" that give you best pitch and on others the pitch bar on the
> flight director just gives you all the pitch info you need ( you just
> put the airplane wings on a magenta bar, no brains required)
> note this is for a sustained and powerful microburst and not for
> recovery form a tiny bit of wind shear in a 20 knot wind.
>
> Bertie

That's what I couldn't remember; I recalled the DFW incident (drove by
a couple of weeks after- messy) and remembered reading about the sim
duplication. Yep. Pull back would take some sim work I'd think to
ingrain something that seems so counter-intuitive.

So, pull back, firewall, recover, enjoy the shaking hands/knees,
change underwear. Gotcha. Oh, land, have beer.

[Bertie the Bunyip[_24_]]

wrote in
:

> On Mar 14, 11:58*am, Bertie the Bunyip > wrote:
>> wrote
>> innews:b887a328-823a-4aa9-8af0-75e24eadf0f2@p25
> g2000hsf.googlegroups.com:
>>
>>
>>
>> > On Mar 14, 11:37*am, Bertie the Bunyip > wrote:
>> >> TakeFlight > wrote in
>> >> news:935d6394-8224-482e-9428-
>> >> :
>>
>> >> > Put me in the "not enough info" column.
>>
>> >> > Plane #2 could be in fact _in_ a stall (or spin), "descending
>> >> > fast with 50% power" or _more_. *Think Delta Flight 191, for
>> >> > example.
>>
>> >> That was something else entirely. That was a microburst. The rules
>> >> pretty much go out the window with one of those.
>> >> not to say the laws of physics are suspended, but it's a scenario
>> >> that is so different from what we learn as pilots that drastic
>> >> retraining was * introduced right across the board after it.
>> >> Flight guidance systems were modified to account for the new
>> >> methods, so it's not really relevant.
>>
>> >> Just to give you some idea of what I mean, I'll give you a
>> >> scenario. You'v
>> > e
>> >> just aken off and yoou're climibing away at best rate. Suddenly,
>> >> your airspeed increases by a fairly large lump. 15-20 knots, say.
>> >> you increase your pitcha bit to absorb it and your speed bleeds
>> >> back a tad. Still plent
>> > y
>> >> in hand, though. all the sudden the pitch you have is dragging
>> >> your speed back and it's beginning to decrease as the wind that
>> >> delivered that extra speed vanishes. You're still OK and back to
>> >> your orignal pitch and have a couple of knots more than you had at
>> >> the beginning. All the sudden, the bottom falls out of your
>> >> airplane. Your climb stops and then a second late
>> > r *
>> >> you begin to sink, and fast. another second or two and your speed
>> >> washes off even further and now you're sinkng and your stall
>> >> warning is starting to squeak.
>>
>> >> you gotta do something and right now. you still have some
>> >> altitude, say 40
>> > 0
>> >> feet. what do you do?
>>
>> >> Bertie
>>
>> > Alt-Ctl-Del
>>
>> > No, wait, change my underwear.
>>
>> > Yoke forward, nose down and max power?
>>
>> That's what the Delta guys did. And that 727 in New Orleans. A
>> different approach was needed and what they came up with was full
>> power. and in a jet that means firewall and overboost to your little
>> heart's contenet, and nose up as much as you can. The stall warnign
>> should be ringing off the wall ( we have stick shakers, but same
>> thing) and you keep this up til you fly out the other side of the
>> mess. It goes against everything we've learned but that's what they
>> tell us to do. There's generally some guidance form the flight
>> director as well. On some it's a set of yellow "antlers" that give
>> you best pitch and on others the pitch bar on the flight director
>> just gives you all the pitch info you need ( you just put the
>> airplane wings on a magenta bar, no brains required) note this is for
>> a sustained and powerful microburst and not for recovery form a tiny
>> bit of wind shear in a 20 knot wind.
>>
>> Bertie
>
> That's what I couldn't remember; I recalled the DFW incident (drove by
> a couple of weeks after- messy) and remembered reading about the sim
> duplication. Yep. Pull back would take some sim work I'd think to
> ingrain something that seems so counter-intuitive.


Exactly.
>
> So, pull back, firewall, recover, enjoy the shaking hands/knees,
> change underwear. Gotcha. Oh, land, have beer.

Absolutely!

Best to stay well away form them anyway!
Oh yeah. I almost forgot, we have a computer that detects windshear and
we get an aural warning and an annunciator. All a legacy of that
accident..


Bertie
>

[[email protected]]

On Mar 14, 12:08*pm, Bertie the Bunyip > wrote:
> wrote :
>
>
>
> > On Mar 14, 11:58*am, Bertie the Bunyip > wrote:
> >> wrote
> >> innews:b887a328-823a-4aa9-8af0-75e24eadf0f2@p25
> > g2000hsf.googlegroups.com:
>
> >> > On Mar 14, 11:37*am, Bertie the Bunyip > wrote:
> >> >> TakeFlight > wrote in
> >> >> news:935d6394-8224-482e-9428-
> >> >> :
>
> >> >> > Put me in the "not enough info" column.
>
> >> >> > Plane #2 could be in fact _in_ a stall (or spin), "descending
> >> >> > fast with 50% power" or _more_. *Think Delta Flight 191, for
> >> >> > example.
>
> >> >> That was something else entirely. That was a microburst. The rules
> >> >> pretty much go out the window with one of those.
> >> >> not to say the laws of physics are suspended, but it's a scenario
> >> >> that is so different from what we learn as pilots that drastic
> >> >> retraining was * introduced right across the board after it.
> >> >> Flight guidance systems were modified to account for the new
> >> >> methods, so it's not really relevant.
>
> >> >> Just to give you some idea of what I mean, I'll give you a
> >> >> scenario. You'v
> >> > e
> >> >> just aken off and yoou're climibing away at best rate. Suddenly,
> >> >> your airspeed increases by a fairly large lump. 15-20 knots, say.
> >> >> you increase your pitcha bit to absorb it and your speed bleeds
> >> >> back a tad. Still plent
> >> > y
> >> >> in hand, though. all the sudden the pitch you have is dragging
> >> >> your speed back and it's beginning to decrease as the wind that
> >> >> delivered that extra speed vanishes. You're still OK and back to
> >> >> your orignal pitch and have a couple of knots more than you had at
> >> >> the beginning. All the sudden, the bottom falls out of your
> >> >> airplane. Your climb stops and then a second late
> >> > r *
> >> >> you begin to sink, and fast. another second or two and your speed
> >> >> washes off even further and now you're sinkng and your stall
> >> >> warning is starting to squeak.
>
> >> >> you gotta do something and right now. you still have some
> >> >> altitude, say 40
> >> > 0
> >> >> feet. what do you do?
>
> >> >> Bertie
>
> >> > Alt-Ctl-Del
>
> >> > No, wait, change my underwear.
>
> >> > Yoke forward, nose down and max power?
>
> >> That's what the Delta guys did. And that 727 in New Orleans. A
> >> different approach was needed and what they came up with was full
> >> power. and in a jet that means firewall and overboost to your little
> >> heart's contenet, and nose up as much as you can. The stall warnign
> >> should be ringing off the wall ( we have stick shakers, but same
> >> thing) and you keep this up til you fly out the other side of the
> >> mess. It goes against everything we've learned but that's what they
> >> tell us to do. There's generally some guidance form the flight
> >> director as well. On some it's a set of yellow "antlers" that give
> >> you best pitch and on others the pitch bar on the flight director
> >> just gives you all the pitch info you need ( you just put the
> >> airplane wings on a magenta bar, no brains required) note this is for
> >> a sustained and powerful microburst and not for recovery form a tiny
> >> bit of wind shear in a 20 knot wind.
>
> >> Bertie
>
> > That's what I couldn't remember; I recalled the DFW incident (drove by
> > a couple of weeks after- messy) and remembered reading about the sim
> > duplication. *Yep. *Pull back would take some sim work I'd think to
> > ingrain something that seems so counter-intuitive.
>
> Exactly.
>
>
>
> > So, pull back, firewall, recover, enjoy the shaking hands/knees,
> > change underwear. *Gotcha. Oh, land, have beer.
>
> Absolutely!
>
> Best to stay well away form them anyway!
> Oh yeah. I almost forgot, we have a computer that detects windshear and
> we get an aural warning and an annunciator. All a legacy of that
> accident..
>
> Bertie
>
>


Got me thinking about beer:30 after jumping. Sigh. Now I miss the
planes, the jumping, the women, the beer. Hanging under a ram air on
high altitude (12K) jump and floating for 20 minutes in the cool
air...unlimited visibility. Just you, the harness and 200 sqft of
nylon. Think I'll have a beer. But I do miss the flying.

[Dan[_10_]]

On Mar 14, 9:27 am, WingFlaps > wrote:
> On Mar 15, 12:08 am, Dan > wrote:
>
> > On Mar 13, 9:57 pm, WingFlaps > wrote:
>
> > > On Mar 14, 2:46 pm, Dan > wrote:
>
> > > > On Mar 13, 8:50 pm, WingFlaps > wrote:
>
> > > > > On Mar 14, 1:00 pm, wrote:
>
> > > > > > On Mar 13, 1:37 pm, WingFlaps > wrote:
>
> > > > > > > Nope, if the airspeed is constant, the lift from the two wings is not
> > > > > > > the same. This is thought provoking discussion I was hoping to start!
> > > > > > > Can you see why lift does not equal weight in both cases?
>
> > > > > > Common misconception: that a climbing wing is generating more
> > > > > > lift than a descending wing. If the flight paths are both straight
> > > > > > lines, whether climbing or descending, the lift is the same in both
> > > > > > cases. As Jim said, only a change in the direction of flight will
> > > > > > change the lift/weight ratio. A G-meter (such as in our Citabrias)
> > > > > > will prove it.
> > > > > > If the airspeeds are the same and the flight paths are both
> > > > > > straight, the AOAs are both the same, too. But change the speeds while
> > > > > > leaving the flight paths alone, and the AOA will change. It's why the
> > > > > > airplane has a nose-high attitude in level slow flight as opposed to a
> > > > > > lower nose attitude in level cruise.
>
> > > > > Hi Dan see my rely to Jim. In fact, lift is reduced in a steady climb.
>
> > > > > Cheers
>
> > > > The trust vector is added to the lift vector in a climb, as the drag
> > > > is added to weight.
>
> > > Are you saying that wing lift does not change with attitude in a non-
> > > accelerating frame?
>
> > > Cheers
>
> > Of course it does.
>
> > However -- In a climb thrust acts contrary to drag some component of
> > weight (depending on the angle of climb). Thus the angle of attack is
> > not *necessarily* equal to the angle of climb.
>
> I'm sorry but I'm having trouble understanding where you are coming
> from. In my equations above I wrote that D=Tcos(alpha) and this is
> based on the idea that W,D and L are 3 orthogonal forces. Of course
> you can rewrite them non orthogonally if you please but my expression
> makes good sense (to me anyway). This is why: Imagine a jet in a
> steady vertical climb (alpha=90 degrees). My equation says D=0 so how
> can that be? The answer is that this simplified (wing + engine) model
> is really only considering induced drag and that the thrust line is
> close to 0 AOA (not bad approximations IMHO). For induced drag to be
> zero, wing LIFT _must_ be zero and so we see that Weight =Tsin(90) + L
> -> W=T -exactly as it should be for a vertical climb! The pilot has
> reduced AOA to zero, the wing produces NO lift and the plane climbs
> vertically. Again, I say L should be dropped to zero for a true steady
> vertical climb and L=W only in straight and level flight or if the
> plane is gliding (T=0). In all steady climbs L<W and all descents L>W.
>
> I was a bit surprised when I realized that to be in a steady climb
> the pilot must be operating the plane in a condition where wing lift
> and AOA are actually lower than in straight and level -all thanks to
> a component of thrust adding to lift !!! Although the effect may not
> be large for low power planes (T<<W) , if what I'm saying makes sense,
> one may see some advantages in this approach -e.g. why increasing
> power leads to a nice steady climb or cutting power causes the nose to
> drop and a descent to begin...
>
> Cheers

Consider -- if you are straight and level at 150 knots with a 3 degree
AOA and you increase the angle of attack to 8 degrees, with no change
in power, what happens?

[WingFlaps]

On Mar 15, 10:32*am, Dan > wrote:
> On Mar 14, 9:27 am, WingFlaps > wrote:
>
>
>
>
>
> > On Mar 15, 12:08 am, Dan > wrote:
>
> > > On Mar 13, 9:57 pm, WingFlaps > wrote:
>
> > > > On Mar 14, 2:46 pm, Dan > wrote:
>
> > > > > On Mar 13, 8:50 pm, WingFlaps > wrote:
>
> > > > > > On Mar 14, 1:00 pm, wrote:
>
> > > > > > > On Mar 13, 1:37 pm, WingFlaps > wrote:
>
> > > > > > > > Nope, if the airspeed is constant, the lift from the two wings is not
> > > > > > > > the same. This is thought provoking discussion I was hoping to start!
> > > > > > > > Can you see why lift does not equal weight in both cases?
>
> > > > > > > * * * Common misconception: that a climbing wing is generating more
> > > > > > > lift than a descending wing. If the flight paths are both straight
> > > > > > > lines, whether *climbing or descending, the lift is the same in both
> > > > > > > cases. As Jim said, only a change in the direction of flight will
> > > > > > > change the lift/weight ratio. A G-meter (such as in our Citabrias)
> > > > > > > will prove it.
> > > > > > > * * * If the airspeeds are the same and the flight paths are both
> > > > > > > straight, the AOAs are both the same, too. But change the speeds while
> > > > > > > leaving the flight paths alone, and the AOA will change. It's why the
> > > > > > > airplane has a nose-high attitude in level slow flight as opposed to a
> > > > > > > lower nose attitude in level cruise.
>
> > > > > > Hi Dan see my rely to Jim. In fact, lift is reduced in a steady climb.
>
> > > > > > Cheers
>
> > > > > The trust vector is added to the lift vector in a climb, as the drag
> > > > > is added to weight.
>
> > > > Are you saying that wing lift does not change with attitude in a non-
> > > > accelerating frame?
>
> > > > Cheers
>
> > > Of course it does.
>
> > > However -- In a climb thrust acts contrary to drag some component of
> > > weight (depending on the angle of climb). Thus the angle of attack is
> > > not *necessarily* equal to the angle of climb.
>
> > I'm sorry but I'm having trouble understanding where you are coming
> > from. In my equations above I wrote that D=Tcos(alpha) and this is
> > based on the idea that W,D and L are 3 orthogonal forces. Of course
> > you can rewrite them non orthogonally if you please but my expression
> > makes good sense (to me anyway). This is why: Imagine a jet in a
> > steady vertical climb (alpha=90 degrees). My equation says D=0 so how
> > can that be? The answer is that this simplified (wing + engine) model
> > is really only considering induced drag and that the thrust line is
> > close to 0 AOA (not bad approximations IMHO). For induced drag to be
> > zero, wing LIFT _must_ be zero and so we see that Weight =Tsin(90) + L
> > -> *W=T -exactly as it should be for a vertical climb! The pilot has
> > reduced AOA to zero, the wing produces NO lift and the plane climbs
> > vertically. Again, I say L should be dropped to zero for a true steady
> > vertical climb and L=W only in straight and level flight or if the
> > plane is gliding (T=0). In all steady climbs L<W and all descents L>W.
>
> > I was a bit surprised when I realized that *to be in a steady climb
> > the pilot must be operating the plane in a condition where wing lift
> > and AOA *are actually lower than in straight and level -all thanks to
> > a component of thrust adding to lift !!! Although the effect may not
> > be large for low power planes (T<<W) , if what I'm saying makes sense,
> > one may see some advantages in this approach -e.g. why increasing
> > power leads to a nice steady climb or cutting power causes the nose to
> > drop and a descent to begin...
>
> > Cheers
>
> Consider -- if you are straight and level at 150 knots with a 3 degree
> AOA and you increase the angle of attack to 8 degrees, with no change
> in power, what happens?- Hide quoted text -
>

You initially increase lift so the plane starts to acclerate in the
vertical plane and the increased drag starts to slow you down -so your
airspeed also comes back. As the airspeed deacys lift starts to drop
(with V^2) and, if you have enough power on to establish a steady
climb at 8 degrees AOA, you achieve a new state where you have a lower
airspeed and the vertical component of lift from the wing is slightly
less than before you started the climb -the lost lift is replaced by
the engine thrust component. If you don't get it, keep thinking about
the steady vertical climb -what is the force that opposes weight? It's
thrust pure and simple right? That force is a sine function of
angle... OK?

Cheers

[Dan[_10_]]

On Mar 14, 5:59 pm, WingFlaps > wrote:
> On Mar 15, 10:32 am, Dan > wrote:
>
>
>
> > On Mar 14, 9:27 am, WingFlaps > wrote:
>
> > > On Mar 15, 12:08 am, Dan > wrote:
>
> > > > On Mar 13, 9:57 pm, WingFlaps > wrote:
>
> > > > > On Mar 14, 2:46 pm, Dan > wrote:
>
> > > > > > On Mar 13, 8:50 pm, WingFlaps > wrote:
>
> > > > > > > On Mar 14, 1:00 pm, wrote:
>
> > > > > > > > On Mar 13, 1:37 pm, WingFlaps > wrote:
>
> > > > > > > > > Nope, if the airspeed is constant, the lift from the two wings is not
> > > > > > > > > the same. This is thought provoking discussion I was hoping to start!
> > > > > > > > > Can you see why lift does not equal weight in both cases?
>
> > > > > > > > Common misconception: that a climbing wing is generating more
> > > > > > > > lift than a descending wing. If the flight paths are both straight
> > > > > > > > lines, whether climbing or descending, the lift is the same in both
> > > > > > > > cases. As Jim said, only a change in the direction of flight will
> > > > > > > > change the lift/weight ratio. A G-meter (such as in our Citabrias)
> > > > > > > > will prove it.
> > > > > > > > If the airspeeds are the same and the flight paths are both
> > > > > > > > straight, the AOAs are both the same, too. But change the speeds while
> > > > > > > > leaving the flight paths alone, and the AOA will change. It's why the
> > > > > > > > airplane has a nose-high attitude in level slow flight as opposed to a
> > > > > > > > lower nose attitude in level cruise.
>
> > > > > > > Hi Dan see my rely to Jim. In fact, lift is reduced in a steady climb.
>
> > > > > > > Cheers
>
> > > > > > The trust vector is added to the lift vector in a climb, as the drag
> > > > > > is added to weight.
>
> > > > > Are you saying that wing lift does not change with attitude in a non-
> > > > > accelerating frame?
>
> > > > > Cheers
>
> > > > Of course it does.
>
> > > > However -- In a climb thrust acts contrary to drag some component of
> > > > weight (depending on the angle of climb). Thus the angle of attack is
> > > > not *necessarily* equal to the angle of climb.
>
> > > I'm sorry but I'm having trouble understanding where you are coming
> > > from. In my equations above I wrote that D=Tcos(alpha) and this is
> > > based on the idea that W,D and L are 3 orthogonal forces. Of course
> > > you can rewrite them non orthogonally if you please but my expression
> > > makes good sense (to me anyway). This is why: Imagine a jet in a
> > > steady vertical climb (alpha=90 degrees). My equation says D=0 so how
> > > can that be? The answer is that this simplified (wing + engine) model
> > > is really only considering induced drag and that the thrust line is
> > > close to 0 AOA (not bad approximations IMHO). For induced drag to be
> > > zero, wing LIFT _must_ be zero and so we see that Weight =Tsin(90) + L
> > > -> W=T -exactly as it should be for a vertical climb! The pilot has
> > > reduced AOA to zero, the wing produces NO lift and the plane climbs
> > > vertically. Again, I say L should be dropped to zero for a true steady
> > > vertical climb and L=W only in straight and level flight or if the
> > > plane is gliding (T=0). In all steady climbs L<W and all descents L>W.
>
> > > I was a bit surprised when I realized that to be in a steady climb
> > > the pilot must be operating the plane in a condition where wing lift
> > > and AOA are actually lower than in straight and level -all thanks to
> > > a component of thrust adding to lift !!! Although the effect may not
> > > be large for low power planes (T<<W) , if what I'm saying makes sense,
> > > one may see some advantages in this approach -e.g. why increasing
> > > power leads to a nice steady climb or cutting power causes the nose to
> > > drop and a descent to begin...
>
> > > Cheers
>
> > Consider -- if you are straight and level at 150 knots with a 3 degree
> > AOA and you increase the angle of attack to 8 degrees, with no change
> > in power, what happens?- Hide quoted text -
>
> You initially increase lift so the plane starts to acclerate in the
> vertical plane and the increased drag starts to slow you down -so your
> airspeed also comes back. As the airspeed deacys lift starts to drop
> (with V^2) and, if you have enough power on to establish a steady
> climb at 8 degrees AOA, you achieve a new state where you have a lower
> airspeed and the vertical component of lift from the wing is slightly
> less than before you started the climb -the lost lift is replaced by
> the engine thrust component. If you don't get it, keep thinking about
> the steady vertical climb -what is the force that opposes weight? It's
> thrust pure and simple right? That force is a sine function of
> angle... OK?
>
> Cheers

I know the answer..wasn't sure if you were thinking beyond the slide
rule.

[WingFlaps]

On Mar 15, 11:08*am, Dan > wrote:
> On Mar 14, 5:59 pm, WingFlaps > wrote:
>
>
>
>
>
> > On Mar 15, 10:32 am, Dan > wrote:
>
> > > On Mar 14, 9:27 am, WingFlaps > wrote:
>
> > > > On Mar 15, 12:08 am, Dan > wrote:
>
> > > > > On Mar 13, 9:57 pm, WingFlaps > wrote:
>
> > > > > > On Mar 14, 2:46 pm, Dan > wrote:
>
> > > > > > > On Mar 13, 8:50 pm, WingFlaps > wrote:
>
> > > > > > > > On Mar 14, 1:00 pm, wrote:
>
> > > > > > > > > On Mar 13, 1:37 pm, WingFlaps > wrote:
>
> > > > > > > > > > Nope, if the airspeed is constant, the lift from the two wings is not
> > > > > > > > > > the same. This is thought provoking discussion I was hoping to start!
> > > > > > > > > > Can you see why lift does not equal weight in both cases?
>
> > > > > > > > > * * * Common misconception: that a climbing wing is generating more
> > > > > > > > > lift than a descending wing. If the flight paths are both straight
> > > > > > > > > lines, whether *climbing or descending, the lift is the same in both
> > > > > > > > > cases. As Jim said, only a change in the direction of flight will
> > > > > > > > > change the lift/weight ratio. A G-meter (such as in our Citabrias)
> > > > > > > > > will prove it.
> > > > > > > > > * * * If the airspeeds are the same and the flight paths are both
> > > > > > > > > straight, the AOAs are both the same, too. But change the speeds while
> > > > > > > > > leaving the flight paths alone, and the AOA will change. It's why the
> > > > > > > > > airplane has a nose-high attitude in level slow flight as opposed to a
> > > > > > > > > lower nose attitude in level cruise.
>
> > > > > > > > Hi Dan see my rely to Jim. In fact, lift is reduced in a steady climb.
>
> > > > > > > > Cheers
>
> > > > > > > The trust vector is added to the lift vector in a climb, as the drag
> > > > > > > is added to weight.
>
> > > > > > Are you saying that wing lift does not change with attitude in a non-
> > > > > > accelerating frame?
>
> > > > > > Cheers
>
> > > > > Of course it does.
>
> > > > > However -- In a climb thrust acts contrary to drag some component of
> > > > > weight (depending on the angle of climb). Thus the angle of attack is
> > > > > not *necessarily* equal to the angle of climb.
>
> > > > I'm sorry but I'm having trouble understanding where you are coming
> > > > from. In my equations above I wrote that D=Tcos(alpha) and this is
> > > > based on the idea that W,D and L are 3 orthogonal forces. Of course
> > > > you can rewrite them non orthogonally if you please but my expression
> > > > makes good sense (to me anyway). This is why: Imagine a jet in a
> > > > steady vertical climb (alpha=90 degrees). My equation says D=0 so how
> > > > can that be? The answer is that this simplified (wing + engine) model
> > > > is really only considering induced drag and that the thrust line is
> > > > close to 0 AOA (not bad approximations IMHO). For induced drag to be
> > > > zero, wing LIFT _must_ be zero and so we see that Weight =Tsin(90) + L
> > > > -> *W=T -exactly as it should be for a vertical climb! The pilot has
> > > > reduced AOA to zero, the wing produces NO lift and the plane climbs
> > > > vertically. Again, I say L should be dropped to zero for a true steady
> > > > vertical climb and L=W only in straight and level flight or if the
> > > > plane is gliding (T=0). In all steady climbs L<W and all descents L>W.
>
> > > > I was a bit surprised when I realized that *to be in a steady climb
> > > > the pilot must be operating the plane in a condition where wing lift
> > > > and AOA *are actually lower than in straight and level -all thanks to
> > > > a component of thrust adding to lift !!! Although the effect may not
> > > > be large for low power planes (T<<W) , if what I'm saying makes sense,
> > > > one may see some advantages in this approach -e.g. why increasing
> > > > power leads to a nice steady climb or cutting power causes the nose to
> > > > drop and a descent to begin...
>
> > > > Cheers
>
> > > Consider -- if you are straight and level at 150 knots with a 3 degree
> > > AOA and you increase the angle of attack to 8 degrees, with no change
> > > in power, what happens?- Hide quoted text -
>
> > You initially increase lift so the plane starts to acclerate in the
> > vertical plane and the increased drag starts to slow you down -so your
> > airspeed also comes back. As the airspeed deacys lift starts to drop
> > (with V^2) and, if you have enough power on to establish a steady
> > climb at 8 degrees AOA, you achieve a new state where you have a lower
> > airspeed and the vertical component of lift from the wing is slightly
> > less than before you started the climb -the lost lift is replaced by
> > the engine thrust component. If you don't get it, keep thinking about
> > the steady vertical climb -what is the force that opposes weight? It's
> > thrust pure and simple right? That force is a sine function of
> > angle... OK?
>
> > Cheers
>
> I know the answer..wasn't sure if you were thinking beyond the slide
> rule.- Hide quoted text -
>

You used slide rules too? Good on ya! So, you agree that vertical lift
is lower in a steady climb -if so is the wing closer to a stall when
climbing or descending at the same speed -is this as thought provoking
as I hoped?

Cheers

[Dan[_10_]]

On Mar 14, 6:42 pm, WingFlaps > wrote:
> On Mar 15, 11:08 am, Dan > wrote:
>
>
>
> > On Mar 14, 5:59 pm, WingFlaps > wrote:
>
> > > On Mar 15, 10:32 am, Dan > wrote:
>
> > > > On Mar 14, 9:27 am, WingFlaps > wrote:
>
> > > > > On Mar 15, 12:08 am, Dan > wrote:
>
> > > > > > On Mar 13, 9:57 pm, WingFlaps > wrote:
>
> > > > > > > On Mar 14, 2:46 pm, Dan > wrote:
>
> > > > > > > > On Mar 13, 8:50 pm, WingFlaps > wrote:
>
> > > > > > > > > On Mar 14, 1:00 pm, wrote:
>
> > > > > > > > > > On Mar 13, 1:37 pm, WingFlaps > wrote:
>
> > > > > > > > > > > Nope, if the airspeed is constant, the lift from the two wings is not
> > > > > > > > > > > the same. This is thought provoking discussion I was hoping to start!
> > > > > > > > > > > Can you see why lift does not equal weight in both cases?
>
> > > > > > > > > > Common misconception: that a climbing wing is generating more
> > > > > > > > > > lift than a descending wing. If the flight paths are both straight
> > > > > > > > > > lines, whether climbing or descending, the lift is the same in both
> > > > > > > > > > cases. As Jim said, only a change in the direction of flight will
> > > > > > > > > > change the lift/weight ratio. A G-meter (such as in our Citabrias)
> > > > > > > > > > will prove it.
> > > > > > > > > > If the airspeeds are the same and the flight paths are both
> > > > > > > > > > straight, the AOAs are both the same, too. But change the speeds while
> > > > > > > > > > leaving the flight paths alone, and the AOA will change. It's why the
> > > > > > > > > > airplane has a nose-high attitude in level slow flight as opposed to a
> > > > > > > > > > lower nose attitude in level cruise.
>
> > > > > > > > > Hi Dan see my rely to Jim. In fact, lift is reduced in a steady climb.
>
> > > > > > > > > Cheers
>
> > > > > > > > The trust vector is added to the lift vector in a climb, as the drag
> > > > > > > > is added to weight.
>
> > > > > > > Are you saying that wing lift does not change with attitude in a non-
> > > > > > > accelerating frame?
>
> > > > > > > Cheers
>
> > > > > > Of course it does.
>
> > > > > > However -- In a climb thrust acts contrary to drag some component of
> > > > > > weight (depending on the angle of climb). Thus the angle of attack is
> > > > > > not *necessarily* equal to the angle of climb.
>
> > > > > I'm sorry but I'm having trouble understanding where you are coming
> > > > > from. In my equations above I wrote that D=Tcos(alpha) and this is
> > > > > based on the idea that W,D and L are 3 orthogonal forces. Of course
> > > > > you can rewrite them non orthogonally if you please but my expression
> > > > > makes good sense (to me anyway). This is why: Imagine a jet in a
> > > > > steady vertical climb (alpha=90 degrees). My equation says D=0 so how
> > > > > can that be? The answer is that this simplified (wing + engine) model
> > > > > is really only considering induced drag and that the thrust line is
> > > > > close to 0 AOA (not bad approximations IMHO). For induced drag to be
> > > > > zero, wing LIFT _must_ be zero and so we see that Weight =Tsin(90) + L
> > > > > -> W=T -exactly as it should be for a vertical climb! The pilot has
> > > > > reduced AOA to zero, the wing produces NO lift and the plane climbs
> > > > > vertically. Again, I say L should be dropped to zero for a true steady
> > > > > vertical climb and L=W only in straight and level flight or if the
> > > > > plane is gliding (T=0). In all steady climbs L<W and all descents L>W.
>
> > > > > I was a bit surprised when I realized that to be in a steady climb
> > > > > the pilot must be operating the plane in a condition where wing lift
> > > > > and AOA are actually lower than in straight and level -all thanks to
> > > > > a component of thrust adding to lift !!! Although the effect may not
> > > > > be large for low power planes (T<<W) , if what I'm saying makes sense,
> > > > > one may see some advantages in this approach -e.g. why increasing
> > > > > power leads to a nice steady climb or cutting power causes the nose to
> > > > > drop and a descent to begin...
>
> > > > > Cheers
>
> > > > Consider -- if you are straight and level at 150 knots with a 3 degree
> > > > AOA and you increase the angle of attack to 8 degrees, with no change
> > > > in power, what happens?- Hide quoted text -
>
> > > You initially increase lift so the plane starts to acclerate in the
> > > vertical plane and the increased drag starts to slow you down -so your
> > > airspeed also comes back. As the airspeed deacys lift starts to drop
> > > (with V^2) and, if you have enough power on to establish a steady
> > > climb at 8 degrees AOA, you achieve a new state where you have a lower
> > > airspeed and the vertical component of lift from the wing is slightly
> > > less than before you started the climb -the lost lift is replaced by
> > > the engine thrust component. If you don't get it, keep thinking about
> > > the steady vertical climb -what is the force that opposes weight? It's
> > > thrust pure and simple right? That force is a sine function of
> > > angle... OK?
>
> > > Cheers
>
> > I know the answer..wasn't sure if you were thinking beyond the slide
> > rule.- Hide quoted text -
>
> You used slide rules too? Good on ya! So, you agree that vertical lift
> is lower in a steady climb -if so is the wing closer to a stall when
> climbing or descending at the same speed -is this as thought provoking
> as I hoped?
>
> Cheers

Slide rules -- oh so long ago! Though I can still spin a whiz wheel...

Vertical lift may be equal to lift in a descent, or in straight and
level.

N'est pas?

Dan Mcc

[WingFlaps]

On Mar 15, 1:31*pm, Dan > wrote:
> On Mar 14, 6:42 pm, WingFlaps > wrote:
>
>
>
>
>
> > On Mar 15, 11:08 am, Dan > wrote:
>
> > > On Mar 14, 5:59 pm, WingFlaps > wrote:
>
> > > > On Mar 15, 10:32 am, Dan > wrote:
>
> > > > > On Mar 14, 9:27 am, WingFlaps > wrote:
>
> > > > > > On Mar 15, 12:08 am, Dan > wrote:
>
> > > > > > > On Mar 13, 9:57 pm, WingFlaps > wrote:
>
> > > > > > > > On Mar 14, 2:46 pm, Dan > wrote:
>
> > > > > > > > > On Mar 13, 8:50 pm, WingFlaps > wrote:
>
> > > > > > > > > > On Mar 14, 1:00 pm, wrote:
>
> > > > > > > > > > > On Mar 13, 1:37 pm, WingFlaps > wrote:
>
> > > > > > > > > > > > Nope, if the airspeed is constant, the lift from the two wings is not
> > > > > > > > > > > > the same. This is thought provoking discussion I was hoping to start!
> > > > > > > > > > > > Can you see why lift does not equal weight in both cases?
>
> > > > > > > > > > > * * * Common misconception: that a climbing wing is generating more
> > > > > > > > > > > lift than a descending wing. If the flight paths are both straight
> > > > > > > > > > > lines, whether *climbing or descending, the lift is the same in both
> > > > > > > > > > > cases. As Jim said, only a change in the direction of flight will
> > > > > > > > > > > change the lift/weight ratio. A G-meter (such as in our Citabrias)
> > > > > > > > > > > will prove it.
> > > > > > > > > > > * * * If the airspeeds are the same and the flight paths are both
> > > > > > > > > > > straight, the AOAs are both the same, too. But change the speeds while
> > > > > > > > > > > leaving the flight paths alone, and the AOA will change. It's why the
> > > > > > > > > > > airplane has a nose-high attitude in level slow flight as opposed to a
> > > > > > > > > > > lower nose attitude in level cruise.
>
> > > > > > > > > > Hi Dan see my rely to Jim. In fact, lift is reduced in a steady climb.
>
> > > > > > > > > > Cheers
>
> > > > > > > > > The trust vector is added to the lift vector in a climb, as the drag
> > > > > > > > > is added to weight.
>
> > > > > > > > Are you saying that wing lift does not change with attitude in a non-
> > > > > > > > accelerating frame?
>
> > > > > > > > Cheers
>
> > > > > > > Of course it does.
>
> > > > > > > However -- In a climb thrust acts contrary to drag some component of
> > > > > > > weight (depending on the angle of climb). Thus the angle of attack is
> > > > > > > not *necessarily* equal to the angle of climb.
>
> > > > > > I'm sorry but I'm having trouble understanding where you are coming
> > > > > > from. In my equations above I wrote that D=Tcos(alpha) and this is
> > > > > > based on the idea that W,D and L are 3 orthogonal forces. Of course
> > > > > > you can rewrite them non orthogonally if you please but my expression
> > > > > > makes good sense (to me anyway). This is why: Imagine a jet in a
> > > > > > steady vertical climb (alpha=90 degrees). My equation says D=0 so how
> > > > > > can that be? The answer is that this simplified (wing + engine) model
> > > > > > is really only considering induced drag and that the thrust line is
> > > > > > close to 0 AOA (not bad approximations IMHO). For induced drag to be
> > > > > > zero, wing LIFT _must_ be zero and so we see that Weight =Tsin(90) + L
> > > > > > -> *W=T -exactly as it should be for a vertical climb! The pilot has
> > > > > > reduced AOA to zero, the wing produces NO lift and the plane climbs
> > > > > > vertically. Again, I say L should be dropped to zero for a true steady
> > > > > > vertical climb and L=W only in straight and level flight or if the
> > > > > > plane is gliding (T=0). In all steady climbs L<W and all descents L>W.
>
> > > > > > I was a bit surprised when I realized that *to be in a steady climb
> > > > > > the pilot must be operating the plane in a condition where wing lift
> > > > > > and AOA *are actually lower than in straight and level -all thanks to
> > > > > > a component of thrust adding to lift !!! Although the effect may not
> > > > > > be large for low power planes (T<<W) , if what I'm saying makes sense,
> > > > > > one may see some advantages in this approach -e.g. why increasing
> > > > > > power leads to a nice steady climb or cutting power causes the nose to
> > > > > > drop and a descent to begin...
>
> > > > > > Cheers
>
> > > > > Consider -- if you are straight and level at 150 knots with a 3 degree
> > > > > AOA and you increase the angle of attack to 8 degrees, with no change
> > > > > in power, what happens?- Hide quoted text -
>
> > > > You initially increase lift so the plane starts to acclerate in the
> > > > vertical plane and the increased drag starts to slow you down -so your
> > > > airspeed also comes back. As the airspeed deacys lift starts to drop
> > > > (with V^2) and, if you have enough power on to establish a steady
> > > > climb at 8 degrees AOA, you achieve a new state where you have a lower
> > > > airspeed and the vertical component of lift from the wing is slightly
> > > > less than before you started the climb -the lost lift is replaced by
> > > > the engine thrust component. If you don't get it, keep thinking about
> > > > the steady vertical climb -what is the force that opposes weight? It's
> > > > thrust pure and simple right? That force is a sine function of
> > > > angle... OK?
>
> > > > Cheers
>
> > > I know the answer..wasn't sure if you were thinking beyond the slide
> > > rule.- Hide quoted text -
>
> > You used slide rules too? Good on ya! So, you agree that vertical lift
> > is lower in a steady climb -if so is the wing closer to a stall when
> > climbing or descending at the same speed -is this as thought provoking
> > as I hoped?
>
> > Cheers
>
> Slide rules -- oh so long ago! Though I can still spin a whiz wheel...
>
> Vertical lift may be equal to lift in a descent, or in straight and
> level.
>
> N'est pas?
>

Yes, but not equal to weight unless thrust is purely horizontal. Not
sure about the French tho' is that slang for n'est-ce pas?

Cheers

[James Carlson]

writes:
> That's what I couldn't remember; I recalled the DFW incident (drove by
> a couple of weeks after- messy) and remembered reading about the sim
> duplication. Yep. Pull back would take some sim work I'd think to
> ingrain something that seems so counter-intuitive.
>
> So, pull back, firewall, recover, enjoy the shaking hands/knees,
> change underwear. Gotcha. Oh, land, have beer.

One beer? Now that's nerves of steel.

--
James Carlson, Solaris Networking >
Sun Microsystems / 35 Network Drive 71.232W Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677

[Roger[_4_]]

On Fri, 14 Mar 2008 16:58:35 +0000 (UTC), Bertie the Bunyip >
wrote:

wrote in
:
>
>> On Mar 14, 11:37*am, Bertie the Bunyip > wrote:
>>> TakeFlight > wrote in
>>> news:935d6394-8224-482e-9428-
>>> :
>>>
>>> > Put me in the "not enough info" column.
>>>
>>> > Plane #2 could be in fact _in_ a stall (or spin), "descending fast
>>> > with 50% power" or _more_. *Think Delta Flight 191, for example.
>>>
>>> That was something else entirely. That was a microburst. The rules
>>> pretty much go out the window with one of those.
>>> not to say the laws of physics are suspended, but it's a scenario
>>> that is so different from what we learn as pilots that drastic
>>> retraining was * introduced right across the board after it. Flight
>>> guidance systems were modified to account for the new methods, so
>>> it's not really relevant.
>>>
>>> Just to give you some idea of what I mean, I'll give you a scenario.
>>> You'v
>> e
>>> just aken off and yoou're climibing away at best rate. Suddenly, your
>>> airspeed increases by a fairly large lump. 15-20 knots, say. you
>>> increase your pitcha bit to absorb it and your speed bleeds back a
>>> tad. Still plent
>> y
>>> in hand, though. all the sudden the pitch you have is dragging your
>>> speed back and it's beginning to decrease as the wind that delivered
>>> that extra speed vanishes. You're still OK and back to your orignal
>>> pitch and have a couple of knots more than you had at the beginning.
>>> All the sudden, the bottom falls out of your airplane. Your climb
>>> stops and then a second late
>> r *
>>> you begin to sink, and fast. another second or two and your speed
>>> washes off even further and now you're sinkng and your stall warning
>>> is starting to squeak.
>>>
>>> you gotta do something and right now. you still have some altitude,
>>> say 40
>> 0
>>> feet. what do you do?
>>>
>>> Bertie
>>
>> Alt-Ctl-Del
>>
>> No, wait, change my underwear.
>>
>> Yoke forward, nose down and max power?
>
>That's what the Delta guys did. And that 727 in New Orleans. A different
>approach was needed and what they came up with was full power. and in a
>jet that means firewall and overboost to your little heart's contenet,
>and nose up as much as you can. The stall warnign should be ringing off

Bertie, this brings up an incident I had in the Cherokee 180 many
years ago. It resulted in quite a discussion with many asserting I
didn't do the right things and quite possibly I didn't but I'd like
your input.

I was on final for 06 at our airport. It was a gusty day so I was
carrying a good 90 on final when at 300 feet the ASI basically and
abruptly went to zip and I was on the express elevator down. I'd never
seen the ASI drop to the peg like that. I knew two things. What
nature takes away in gusts she eventually gives back. The other was at
300 feet and essentially zero for IAS I'd become a lawn dart if I
shoved the nose down as I was not going to accelerate enough get
flying speed and enough energy to flare in that distance unless the
wind changed. It would have been different if the ASI had been a
little low or at least had some indication.

Of course at the first instance of sink I instinctively went full
power. The only thing I could think of at that point was to put the
plane in the best attitude for survival on impact if it didn't start
flying. The one thing I didn't want was to hit nose low. The
airspeed came back as I was entering ground effect and at that point I
was able to ease the nose down and pick up a enough speed that I made
a normal landing. Actually the landing was a good one if you didn't
count the last few hundred feet of final. <:-))



>the wall ( we have stick shakers, but same thing) and you keep this up
>til you fly out the other side of the mess. It goes against everything
>we've learned but that's what they tell us to do. There's generally some
>guidance form the flight director as well. On some it's a set of yellow
>"antlers" that give you best pitch and on others the pitch bar on the
>flight director just gives you all the pitch info you need ( you just
>put the airplane wings on a magenta bar, no brains required)
>note this is for a sustained and powerful microburst and not for
>recovery form a tiny bit of wind shear in a 20 knot wind.
>
>Bertie
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

[Bertie the Bunyip[_24_]]

Roger > wrote in
:
> Bertie, this brings up an incident I had in the Cherokee 180 many
> years ago. It resulted in quite a discussion with many asserting I
> didn't do the right things and quite possibly I didn't but I'd like
> your input.
>
> I was on final for 06 at our airport. It was a gusty day so I was
> carrying a good 90 on final when at 300 feet the ASI basically and
> abruptly went to zip and I was on the express elevator down. I'd never
> seen the ASI drop to the peg like that. I knew two things. What
> nature takes away in gusts she eventually gives back. The other was at
> 300 feet and essentially zero for IAS I'd become a lawn dart if I
> shoved the nose down as I was not going to accelerate enough get
> flying speed and enough energy to flare in that distance unless the
> wind changed. It would have been different if the ASI had been a
> little low or at least had some indication.
>
> Of course at the first instance of sink I instinctively went full
> power. The only thing I could think of at that point was to put the
> plane in the best attitude for survival on impact if it didn't start
> flying. The one thing I didn't want was to hit nose low. The
> airspeed came back as I was entering ground effect and at that point I
> was able to ease the nose down and pick up a enough speed that I made
> a normal landing. Actually the landing was a good one if you didn't
> count the last few hundred feet of final. <:-))

Yow! Sounds like you did the right thing to me, alright. Proof is in the
pudding of course and you got away with it, but I have to agree with you,
putting the nose down would have been disasterous. I had a similar
experience to your's in a glider which ended up with us landing short of
the field but no damage. Difficut to train for things lke this though.
Familiarity with the feel of the the airplane at and beyond the edge
obviously paid off for you, I'd say!

Bertie

[Frank Olson]

WingFlaps wrote:
> Hi All,
>
> Imagine a plane in 2 conditions.
>
> 1) Climbing with full power
> 2) Descending fast with 50% power.
>
> Both have constant rates of ascent and descent.
>
> Question A: Which wing is closer to stall?
> Question B: A big updraft occurs, which is more likely to stall?
>
> If you vote first it _may_ lead to some good discussion later...
>
> Cheers


Is the "full power" climb with or without afterburner?? :-)

[EridanMan]

You haven't provided enough information.

> 1) Climbing with full power

What Speed? The pilot selects the AOA when he chooses to either climb
out at Vx, Vy, or a Cruise Climb. Of these, Vx is the closest to the
stall, so lets pick that one for the sake of your question.

> 2) Descending fast with 50% power.

Again, what type of descent? Straight forward and clean? Emergency
Dirty? Because Of lack of specificity, I am going to assume you mean
straight forward and clean, and as such, I'm assuming you mean a high-
speed (cruise) descent.

> Both have constant rates of ascent and descent.

So to clarify, your assuming that all 'zooming' energy has been
expended and the aircraft are in a state of equilibrium?

Also, given that you have not specified a particular aircraft, I am
going to use my own personal Bird's speed's as a reference for all
further questions (PA-28-140).

> Question A: Which wing is closer to stall?

In state 1, the ship is operating at 74mph, on the low side of L/D max
operating in the region of reversed control authority.
In state 2, the ship is operating at its parasitic-Drag-Limited
descent-rate. Lets assume that the pilot is descending at 500fpm
(glide rate, power off). Obviously the pilot is going to be doing a
lot faster than the 80mph Vg, since the plane can do that power off,
and in this case the pilot will be suppling a substantial amount of
energy from the mill... in my bird, 50% power on a cruise descent
gives me ~140mph, but in any case you'll be substantially faster than
the best glide speed.

That said, the answer is trivial, of course the 74tas aircraft is
closer to stall than the 80+tas aircraft.

Granted, there is an odd case, its possible that the pilot is
operating at 50% power, but right ahead of the stall regime in the
region of reversed command authority. In that case, if he is
requiring 50% of his power to maintain a 500fpm descent, he's probably
pretty damn close to the wing's stall threshold... But that would just
be poor judgement on the pilot's part.

> Question B: A big updraft occurs, which is more likely to stall?

I'm not sure Updrafts are your problem so much as tail-winds, but in
any case, obviously the ship that is operating closer to Stall will
have less margin for variances an ambient wind direction.

> If you vote first it _may_ lead to some good discussion later...