Stalls and Thoughts

On Mar 15, 9:52 pm, Dudley Henriques wrote:
Dan wrote:

Wouldn't a more exact definition be that the "region of reversed
command" is that condition where induced drag is at its greatest,
pitch only controls airspeed, and power only controls altitude?
One can "drag in" and airplane and not meet all the aforementioned
conditions.
The usefulness of this condition is apparent in short field landings.


What I think he's saying Dan is that you can drag it in and plop it down
if you do it right and don't screw it up, but it's not the best
procedure and can get you into trouble real fast.
It's not necessary to fly a behind the curve approach into a short
field. In fact, the accepted procedure for short field is nowhere near
back side.

--
Dudley Henriques

So when flying 1.3 Vso is the airplane in or not in the region of
reversed command?

At 67 KIAS in an A36 on final any increase in pitch results in a
descent.

I agree you have to be on top of things in this PAC, but a short field
landing is considered a maximum performance maneuver, and 1.3 Vso is
the target airspeed.


Dan

Dan wrote:
On Mar 15, 9:52 pm, Dudley Henriques wrote:
Dan wrote:

Wouldn't a more exact definition be that the "region of reversed
command" is that condition where induced drag is at its greatest,
pitch only controls airspeed, and power only controls altitude?
One can "drag in" and airplane and not meet all the aforementioned
conditions.
The usefulness of this condition is apparent in short field landings.

What I think he's saying Dan is that you can drag it in and plop it down
if you do it right and don't screw it up, but it's not the best
procedure and can get you into trouble real fast.
It's not necessary to fly a behind the curve approach into a short
field. In fact, the accepted procedure for short field is nowhere near
back side.

--
Dudley Henriques

So when flying 1.3 Vso is the airplane in or not in the region of
reversed command?

At 67 KIAS in an A36 on final any increase in pitch results in a
descent.

I agree you have to be on top of things in this PAC, but a short field
landing is considered a maximum performance maneuver, and 1.3 Vso is
the target airspeed.


Dan



What's the airspeed for maximum endurance in the A36?

--
Dudley Henriques

Bob F. wrote:
Thanks for the response. I heard different stories but nothing that
made sense to me. The closest partial story had something to do with
the props slipstream on the stabilizer (H or V, I don't know) gave them
better performance (whatever that means) in high speed, high powered
dives. I could never get a complete story. I even talked with 3 of the
last pilots that shot down Adm. Yamamoto, when they gave a talk at the
Boeing Museum about 20 years ago. They had no idea either.

The slipstream I believe could very well have been a factor although
I've never seen the Schlieren photography from the tunnel tests.
Apparently the direction of the slip stream spiral hitting the vertical
stabilizer from the inward props was causing issues, most likely from
any asymmetricals or differentials in the throttle settings during
gunnery. The guns solution requires a center ball or there's a high
degree of trajectory shift .
Tony LeVier would have been the guy to settle up on this issue. He and
Kelsey did most of the tests on the 38. I met him during the L1011
program. Great guy.


--
Dudley Henriques

On Mar 16, 6:58 am, Dudley Henriques wrote:
Dan wrote:
On Mar 15, 9:52 pm, Dudley Henriques wrote:
Dan wrote:

Wouldn't a more exact definition be that the "region of reversed
command" is that condition where induced drag is at its greatest,
pitch only controls airspeed, and power only controls altitude?
One can "drag in" and airplane and not meet all the aforementioned
conditions.
The usefulness of this condition is apparent in short field landings.

What I think he's saying Dan is that you can drag it in and plop it down
if you do it right and don't screw it up, but it's not the best
procedure and can get you into trouble real fast.
It's not necessary to fly a behind the curve approach into a short
field. In fact, the accepted procedure for short field is nowhere near
back side.

--
Dudley Henriques

So when flying 1.3 Vso is the airplane in or not in the region of
reversed command?

At 67 KIAS in an A36 on final any increase in pitch results in a
descent.

I agree you have to be on top of things in this PAC, but a short field
landing is considered a maximum performance maneuver, and 1.3 Vso is
the target airspeed.

Dan

What's the airspeed for maximum endurance in the A36?

--
Dudley Henriques

110 KIAS

On Mar 16, 6:58 am, Dudley Henriques wrote:
Dan wrote:
On Mar 15, 9:52 pm, Dudley Henriques wrote:
Dan wrote:

Wouldn't a more exact definition be that the "region of reversed
command" is that condition where induced drag is at its greatest,
pitch only controls airspeed, and power only controls altitude?
One can "drag in" and airplane and not meet all the aforementioned
conditions.
The usefulness of this condition is apparent in short field landings.

What I think he's saying Dan is that you can drag it in and plop it down
if you do it right and don't screw it up, but it's not the best
procedure and can get you into trouble real fast.
It's not necessary to fly a behind the curve approach into a short
field. In fact, the accepted procedure for short field is nowhere near
back side.

--
Dudley Henriques

So when flying 1.3 Vso is the airplane in or not in the region of
reversed command?

At 67 KIAS in an A36 on final any increase in pitch results in a
descent.

I agree you have to be on top of things in this PAC, but a short field
landing is considered a maximum performance maneuver, and 1.3 Vso is
the target airspeed.

Dan

What's the airspeed for maximum endurance in the A36?

--
Dudley Henriques

110 KIAS is book value. To arrive at the exact figure would require a
bit of extrapolation, but wouldn't vary much more than 5 KIAS in
either direction.

Bob F. wrote:
Thanks for the response. I heard different stories but nothing that
made sense to me. The closest partial story had something to do with
the props slipstream on the stabilizer (H or V, I don't know) gave them
better performance (whatever that means) in high speed, high powered
dives. I could never get a complete story. I even talked with 3 of the
last pilots that shot down Adm. Yamamoto, when they gave a talk at the
Boeing Museum about 20 years ago. They had no idea either.

It was good to see Barber finally get his just due on the Yamamoto
issue. Rex was a true gentlemen. He avoided the mess with Lamphier all
through his life.

--
Dudley Henriques

Dan wrote:
On Mar 16, 6:58 am, Dudley Henriques wrote:
Dan wrote:
On Mar 15, 9:52 pm, Dudley Henriques wrote:
Dan wrote:
Wouldn't a more exact definition be that the "region of reversed
command" is that condition where induced drag is at its greatest,
pitch only controls airspeed, and power only controls altitude?
One can "drag in" and airplane and not meet all the aforementioned
conditions.
The usefulness of this condition is apparent in short field landings.
What I think he's saying Dan is that you can drag it in and plop it down
if you do it right and don't screw it up, but it's not the best
procedure and can get you into trouble real fast.
It's not necessary to fly a behind the curve approach into a short
field. In fact, the accepted procedure for short field is nowhere near
back side.
--
Dudley Henriques
So when flying 1.3 Vso is the airplane in or not in the region of
reversed command?
At 67 KIAS in an A36 on final any increase in pitch results in a
descent.
I agree you have to be on top of things in this PAC, but a short field
landing is considered a maximum performance maneuver, and 1.3 Vso is
the target airspeed.
Dan
What's the airspeed for maximum endurance in the A36?

--
Dudley Henriques

110 KIAS is book value. To arrive at the exact figure would require a
bit of extrapolation, but wouldn't vary much more than 5 KIAS in
either direction.

The accepted point that separates the front and back side of the power
curve should be the maximum endurance airspeed for the airplane, but
this assumes a constantly maintained altitude as the airspeed decreases.
Transition into slow flight while maintaining altitude is a good example
of transition along the curve.

--
Dudley Henriques

On Mar 16, 7:22 am, Dudley Henriques wrote:
Dan wrote:
On Mar 16, 6:58 am, Dudley Henriques wrote:
Dan wrote:
On Mar 15, 9:52 pm, Dudley Henriques wrote:
Dan wrote:
Wouldn't a more exact definition be that the "region of reversed
command" is that condition where induced drag is at its greatest,
pitch only controls airspeed, and power only controls altitude?
One can "drag in" and airplane and not meet all the aforementioned
conditions.
The usefulness of this condition is apparent in short field landings.
What I think he's saying Dan is that you can drag it in and plop it down
if you do it right and don't screw it up, but it's not the best
procedure and can get you into trouble real fast.
It's not necessary to fly a behind the curve approach into a short
field. In fact, the accepted procedure for short field is nowhere near
back side.
--
Dudley Henriques
So when flying 1.3 Vso is the airplane in or not in the region of
reversed command?
At 67 KIAS in an A36 on final any increase in pitch results in a
descent.
I agree you have to be on top of things in this PAC, but a short field
landing is considered a maximum performance maneuver, and 1.3 Vso is
the target airspeed.
Dan
What's the airspeed for maximum endurance in the A36?

--
Dudley Henriques

110 KIAS is book value. To arrive at the exact figure would require a
bit of extrapolation, but wouldn't vary much more than 5 KIAS in
either direction.

The accepted point that separates the front and back side of the power
curve should be the maximum endurance airspeed for the airplane, but
this assumes a constantly maintained altitude as the airspeed decreases.
Transition into slow flight while maintaining altitude is a good example
of transition along the curve.

--
Dudley Henriques

Thereby any speed under 110 KIAS could be considered "dragging it in",
which means there's something unclear about the terms.

In the A36, 70 KIAS gives best short field performance -- there's
enough energy to flare if power is lost (not much, but enough), and
yet the airplane lands and stops in a very short distance.

I don't consider that "dragging it in" but it is on the high induced
drag side of the curve.

I think "dragging it in" refers to the practice of setting up a
landing configuration far from the touchdown point, and then applying
lots of power to overcome the high drag configuration to make the
runway.

If you're flying 1.3 Vso you will have a steeper descent angle, which
means kinetic energy is supplementing whatever power may be set, so
you're not at 80% power just to maintain that airspeed.

That's my understanding -- if this is wrong I'd like to know!


Dan

Minor point. In aircraft engineering, you can interpolate but never
extrapolate, as the saying goes. IOW, given two data points, it's
acceptable to find a third in the middle someplace (interpolation), but
never go beyond or outside the graph numbers (extrapolation). You should
not make any predictions about what's out there. That's test pilot area.

--
BobF.
"Dan" wrote in message
...
On Mar 16, 6:58 am, Dudley Henriques wrote:
Dan wrote:
On Mar 15, 9:52 pm, Dudley Henriques wrote:
Dan wrote:

Wouldn't a more exact definition be that the "region of reversed
command" is that condition where induced drag is at its greatest,
pitch only controls airspeed, and power only controls altitude?
One can "drag in" and airplane and not meet all the aforementioned
conditions.
The usefulness of this condition is apparent in short field
landings.

What I think he's saying Dan is that you can drag it in and plop it
down
if you do it right and don't screw it up, but it's not the best
procedure and can get you into trouble real fast.
It's not necessary to fly a behind the curve approach into a short
field. In fact, the accepted procedure for short field is nowhere near
back side.

--
Dudley Henriques

So when flying 1.3 Vso is the airplane in or not in the region of
reversed command?

At 67 KIAS in an A36 on final any increase in pitch results in a
descent.

I agree you have to be on top of things in this PAC, but a short field
landing is considered a maximum performance maneuver, and 1.3 Vso is
the target airspeed.

Dan

What's the airspeed for maximum endurance in the A36?

--
Dudley Henriques

110 KIAS is book value. To arrive at the exact figure would require a
bit of extrapolation, but wouldn't vary much more than 5 KIAS in
either direction.

On Sat, 15 Mar 2008 19:39:13 -0400, Dudley Henriques
wrote:


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.

I thought coffin corner was the point where if you go slower you stall
and if you go faster you hit critical mach number?