Stalls and Thoughts

wrote:
How much of a new students time is spent
flying in slow flight at the low end of the performance envelope?
Isn't that where all the nasty things can happen?

I spent a fair amount of time, probably close to an hour or two in
slow flight. Maybe a little longer.

I don't think it's the case that slow flight is where all the nasty
things can happen. A stall can happen at any speed in any flight
attitude, and may be worse at higher speeds in certain attitudes than
low speed, upright, straight and level.
This is true. Stalls at 1g are seldom the issue. Accelerated stall is
the stall that will kill you. Pilots are well advised to go WELL beyond
understanding stalls with the airplane at 1g. A good look into the realm
of stall over 1g and in ALL flight attitudes, especially cross
controlled is time well spent.

--
Dudley Henriques

"Dan" wrote in message
...
On Mar 15, 4:33 pm, Dudley Henriques wrote:


The analogy "dragging it in" refers to having the airplane configured
behind the power curve or if you wish, in the area of reverse command,
on final approach....a very dangerous situation.

--
Dudley Henriques

Dangerous, but certainly useful at times!

Such as? (I can think of one instance, but I'd like to know if we're on the
same page)

"Dragging it in" does not necessarily mean "in in the area of reverse
command". It just means that you have added power instead of reducing drag
by retracting flaps or gear, etc. "The area of reverse command" is an
exteme example.

--
BobF.
"Matt W. Barrow" wrote in message
...

"Dan" wrote in message
...
On Mar 15, 4:33 pm, Dudley Henriques wrote:


The analogy "dragging it in" refers to having the airplane configured
behind the power curve or if you wish, in the area of reverse command,
on final approach....a very dangerous situation.

--
Dudley Henriques

Dangerous, but certainly useful at times!

Such as? (I can think of one instance, but I'd like to know if we're on
the same page)

Bob F. wrote:
"Dragging it in" does not necessarily mean "in in the area of reverse
command". It just means that you have added power instead of reducing
drag by retracting flaps or gear, etc. "The area of reverse command"
is an exteme example.

The coffin corner of the back side of the power curve is the extreme.
You can add power flaps or no flaps and still be well on the front side
of the power curve.
Generally speaking, if you are "dragging it in, you are most certainly
in the area of reverse command

--
Dudley Henriques

Matt W. Barrow wrote:
"Dan" wrote in message
...
On Mar 15, 4:33 pm, Dudley Henriques wrote:

The analogy "dragging it in" refers to having the airplane configured
behind the power curve or if you wish, in the area of reverse command,
on final approach....a very dangerous situation.

--
Dudley Henriques
Dangerous, but certainly useful at times!

Such as? (I can think of one instance, but I'd like to know if we're on the
same page)


I hope he's not thinking of carrier approaches; popular misconception!

--
Dudley Henriques

"Generally"?, "most certainly"?, I'd say "in one case". The other way
around is correct. That is "if you are in the area of reverse command, you
are dragging it in". Notwithstanding that the phrase includes the notion of
approaching and/or landing. The coffin corner is also not on the back side
of the power curve. It is at the asymptote and you can never get into the
back side. That's why it a corner. It is certainly not referred to as
"dragging it in" there. Been there with the best test pilots in the world
in a 747-400 while I was testing the 400. No one has ever referred to is as
that.

--
BobF.
"Dudley Henriques" wrote in message
...
Bob F. wrote:
"Dragging it in" does not necessarily mean "in in the area of reverse
command". It just means that you have added power instead of reducing
drag by retracting flaps or gear, etc. "The area of reverse command" is
an exteme example.

The coffin corner of the back side of the power curve is the extreme. You
can add power flaps or no flaps and still be well on the front side of the
power curve.
Generally speaking, if you are "dragging it in, you are most certainly in
the area of reverse command

--
Dudley Henriques

Bob F. wrote:
"Generally"?, "most certainly"?, I'd say "in one case". The other way
around is correct. That is "if you are in the area of reverse command,
you are dragging it in". Notwithstanding that the phrase includes the
notion of approaching and/or landing. The coffin corner is also not on
the back side of the power curve. It is at the asymptote and you can
never get into the back side. That's why it a corner. It is certainly
not referred to as "dragging it in" there. Been there with the best
test pilots in the world in a 747-400 while I was testing the 400. No
one has ever referred to is as that.

You're kidding right?

I believe you are repeating wht I have said. I said that "dragging it
in" generally refers to flying the approach in the area of reverse
command or if you will behind the power curve. This is absolutely
correct. Coffin corner is the area behind the curve where sink rate
can't be stopped with power but requires reduction in angle of attack.
For a perfect example of an aircraft in coffin corner, see the Edwards
AFB accident involving a young AF pilot who got his F100 so deep into
coffin corner behind the curve he couldn't recover the airplane; not
enough air under him to reduce the angle of attack. He applied full
burner but couldn't fly it out on power alone. Reduction of angle of
attack was what he needed and he didn't have the room. THIS is the
definition of coffin corner and it most certainly IS in the area of
reverse command.

--
Dudley Henriques

WrongO againO. The "coffin corner" is an altitude (point on a chart where
the stall speed and Mach come together) with a max power setting. If you go
faster, you get mach buffet. If you go to slow, you stall. If you reduce
power setting, you stall. If you nose over to recover, you mach buffet.
With your example I can see why you're confused.

--
BobF.
"Dudley Henriques" wrote in message
...
Bob F. wrote:
"Generally"?, "most certainly"?, I'd say "in one case". The other way
around is correct. That is "if you are in the area of reverse command,
you are dragging it in". Notwithstanding that the phrase includes the
notion of approaching and/or landing. The coffin corner is also not on
the back side of the power curve. It is at the asymptote and you can
never get into the back side. That's why it a corner. It is certainly
not referred to as "dragging it in" there. Been there with the best test
pilots in the world in a 747-400 while I was testing the 400. No one has
ever referred to is as that.

You're kidding right?

I believe you are repeating wht I have said. I said that "dragging it in"
generally refers to flying the approach in the area of reverse command or
if you will behind the power curve. This is absolutely correct. Coffin
corner is the area behind the curve where sink rate can't be stopped with
power but requires reduction in angle of attack.
For a perfect example of an aircraft in coffin corner, see the Edwards AFB
accident involving a young AF pilot who got his F100 so deep into coffin
corner behind the curve he couldn't recover the airplane; not enough air
under him to reduce the angle of attack. He applied full burner but
couldn't fly it out on power alone. Reduction of angle of attack was what
he needed and he didn't have the room. THIS is the definition of coffin
corner and it most certainly IS in the area of reverse command.

--
Dudley Henriques

Bob F. wrote:
WrongO againO. The "coffin corner" is an altitude (point on a chart
where the stall speed and Mach come together) with a max power setting.
If you go faster, you get mach buffet. If you go to slow, you stall.
If you reduce power setting, you stall. If you nose over to recover,
you mach buffet. With your example I can see why you're confused.

I'm not confused and neither are you. :-))

The coffin corner YOU are describing can be found in the flight envelope
of the U2 (as well as other airplanes) at high altitude cruise. The
coffin corner I'm describing can be found on a dragged in approach AT
LOW ALTITUDE with the aircraft behind where the flight test community
defines the area of reverse command; that being below the airspeed for
maximum endurance. The corner is reached as you get the airplane low
enough on the approach where the sink rate can't be stopped with power
as maximum is already applied. The ONLY way out of the corner is to
reduce angle of attack. If the proximity between the aircraft and the
ground won't allow that angle of attack reduction, you hve what we call
the "coffin corner".

--
Dudley Henriques

"Bob F." wrote in
:

WrongO againO. The "coffin corner" is an altitude (point on a chart
where the stall speed and Mach come together) with a max power
setting. If you go faster, you get mach buffet. If you go to slow,
you stall. If you reduce power setting, you stall. If you nose over
to recover, you mach buffet. With your example I can see why you're
confused.


Acctually, the low side buffet isn't strictly a stall. The proof of this is
it happens at a much higher indicated and much lower alpha than a stall at
low altitudes. The wing doe lose lift, so in the broadest definition of a a
stall the wing stals, but what's actualy happening is that the increased
angle of attack you neccesarily have as you reduce speed increases the
speed of the air over the wing so that there are localised areas of
supersonic flow with an accompanying buffet. So what coffin corner actually
is is an onset of mach buffet caused by any combination of speed and alpha.


Bertie