Hey Dudley, detailed analysis of these?

Bertie the Bunyip wrote:


OK, the first one should have been the T6 slow roll where he dished out
in the end.(orange one in south america?)
Looks like he had nothing even beginning the roll and had completely
lost the plot by the time he reached even 45 degrees and should have
just thrown it away at that point.
To me, the KC accident looked like the result of a way too low energy
state going through the top gate. He should have had at least 150
indicated inverted on top but it looked like he lost his energy to
drag going up the up line by pulling too much g. He was practically
dead in the water on top but apparently at fairly high power. This
looked like it torqued him in roll pretty good and he lost it coming
through the gate. He recovered as the angle of attack narrowed back
into the work range but by then he was committed way too nose low and
had no radial g available to affect the recovery.

The guy in the T6, rolling right, judging from the clip, never made the
rudder switch from left to right rudder as he passed through inverted.
His held in left rudder became bottom rudder as he passed through
inverted then yawed him hard as he reached the second knife edge. Add to
this he didn't have enough forward stick in either as he went through
inverted. The combination of the two errors caused the nose to come down
as he rolled into the 3rd quarter.

You just don't do this in a low altitude roll and survive. To me it
looked like bad control coordination beginning at inverted and held
through impact . The first half of the roll looked good BTW. He just
blew it on the second half.
His airspeed looked fine for a T6 going into the roll set so energy
wasn't the issue here.

--
Dudley Henriques

Dudley Henriques wrote in
:

Bertie the Bunyip wrote:


OK, the first one should have been the T6 slow roll where he dished
out
in the end.(orange one in south america?)
Looks like he had nothing even beginning the roll and had completely
lost the plot by the time he reached even 45 degrees and should have
just thrown it away at that point.
To me, the KC accident looked like the result of a way too low
energy
state going through the top gate. He should have had at least 150
indicated inverted on top but it looked like he lost his energy to
drag going up the up line by pulling too much g. He was practically
dead in the water on top but apparently at fairly high power. This
looked like it torqued him in roll pretty good and he lost it coming
through the gate. He recovered as the angle of attack narrowed back
into the work range but by then he was committed way too nose low
and
had no radial g available to affect the recovery.

The guy in the T6, rolling right, judging from the clip, never made
the
rudder switch from left to right rudder as he passed through inverted.
His held in left rudder became bottom rudder as he passed through
inverted then yawed him hard as he reached the second knife edge. Add
to
this he didn't have enough forward stick in either as he went through
inverted. The combination of the two errors caused the nose to come
down
as he rolled into the 3rd quarter.

You just don't do this in a low altitude roll and survive. To me it
looked like bad control coordination beginning at inverted and held
through impact . The first half of the roll looked good BTW. He just
blew it on the second half.
His airspeed looked fine for a T6 going into the roll set so energy
wasn't the issue here.



Hmm, yes, OK. Looked at it again a few times. I still think he's a bit
nose low at the first 90 point which would have exacerbated the nose
down inverted, though. I usually looked for the side of the cowl to be
resting on the horizon at the 90 before commiting to inverted.
I think you're right about the rudder coming through inverted, he got
so absorbed in that problem his rudder control went astray and it
degenerated into just panic thrashing and pulling and hoping for the
best.


Bertie

Bertie the Bunyip wrote:
Dudley Henriques wrote in
:

Bertie the Bunyip wrote:


OK, the first one should have been the T6 slow roll where he dished
out
in the end.(orange one in south america?)
Looks like he had nothing even beginning the roll and had completely
lost the plot by the time he reached even 45 degrees and should have
just thrown it away at that point.
To me, the KC accident looked like the result of a way too low
energy
state going through the top gate. He should have had at least 150
indicated inverted on top but it looked like he lost his energy to
drag going up the up line by pulling too much g. He was practically
dead in the water on top but apparently at fairly high power. This
looked like it torqued him in roll pretty good and he lost it coming
through the gate. He recovered as the angle of attack narrowed back
into the work range but by then he was committed way too nose low
and
had no radial g available to affect the recovery.
The guy in the T6, rolling right, judging from the clip, never made
the
rudder switch from left to right rudder as he passed through inverted.
His held in left rudder became bottom rudder as he passed through
inverted then yawed him hard as he reached the second knife edge. Add
to
this he didn't have enough forward stick in either as he went through
inverted. The combination of the two errors caused the nose to come
down
as he rolled into the 3rd quarter.

You just don't do this in a low altitude roll and survive. To me it
looked like bad control coordination beginning at inverted and held
through impact . The first half of the roll looked good BTW. He just
blew it on the second half.
His airspeed looked fine for a T6 going into the roll set so energy
wasn't the issue here.



Hmm, yes, OK. Looked at it again a few times. I still think he's a bit
nose low at the first 90 point which would have exacerbated the nose
down inverted, though. I usually looked for the side of the cowl to be
resting on the horizon at the 90 before commiting to inverted.
I think you're right about the rudder coming through inverted, he got
so absorbed in that problem his rudder control went astray and it
degenerated into just panic thrashing and pulling and hoping for the
best.


Bertie

The best technique to use in low altitude roll entries is to use adverse
yaw to your advantage as you enter the roll. You need top rudder anyway
and that's the way the nose will go if you don't use rolling rudder into
the roll to coordinate the entry. I just allow the yaw and follow it
closely with top rudder as the roll stabilizes.

A lot of these guys doing low altitude rolls will use inside rudder with
aileron entering the roll because it's the "natural" thing to do. If the
rudder isn't switched immediately to opposite rudder as the roll
initiates, this will naturally be bottom rudder and pull the nose down.
At low altitude, this can get you killed.


--
Dudley Henriques

Dudley Henriques wrote in
:

The best technique to use in low altitude roll entries is to use adverse
yaw to your advantage as you enter the roll. You need top rudder anyway
and that's the way the nose will go if you don't use rolling rudder into
the roll to coordinate the entry. I just allow the yaw and follow it
closely with top rudder as the roll stabilizes.

A lot of these guys doing low altitude rolls will use inside rudder with
aileron entering the roll because it's the "natural" thing to do. If the
rudder isn't switched immediately to opposite rudder as the roll
initiates, this will naturally be bottom rudder and pull the nose down.
At low altitude, this can get you killed.



OK, that's the way I always did it. Rudder into roll until the adverse yaw
is no longer a problem at say about 30 deg. Swiftly to top rudder then. I
found, in most of the draggy things I flew, that if you didn;t, you lost
the point. With the roll rates I'd be dealing with a large aileron input
was required (max aileron, to get even a 2.5 to 3 second roll) and adverse
yaw could be fierce. rudder required was only light though and I was fully
mindful of the consequences of not getting top rudder in quickly! I'm
having trouble remembering how I did a lot of things though since at the
end of the day I just kept the point in place and did the neccesary to keep
it there. I'll have to re-educate myself procedurally, though.


Bertie

Bertie the Bunyip wrote:
Dudley Henriques wrote in
:
The best technique to use in low altitude roll entries is to use adverse
yaw to your advantage as you enter the roll. You need top rudder anyway
and that's the way the nose will go if you don't use rolling rudder into
the roll to coordinate the entry. I just allow the yaw and follow it
closely with top rudder as the roll stabilizes.

A lot of these guys doing low altitude rolls will use inside rudder with
aileron entering the roll because it's the "natural" thing to do. If the
rudder isn't switched immediately to opposite rudder as the roll
initiates, this will naturally be bottom rudder and pull the nose down.
At low altitude, this can get you killed.



OK, that's the way I always did it. Rudder into roll until the adverse yaw
is no longer a problem at say about 30 deg. Swiftly to top rudder then. I
found, in most of the draggy things I flew, that if you didn;t, you lost
the point. With the roll rates I'd be dealing with a large aileron input
was required (max aileron, to get even a 2.5 to 3 second roll) and adverse
yaw could be fierce. rudder required was only light though and I was fully
mindful of the consequences of not getting top rudder in quickly! I'm
having trouble remembering how I did a lot of things though since at the
end of the day I just kept the point in place and did the neccesary to keep
it there. I'll have to re-educate myself procedurally, though.


Bertie
Coordinated rudder into the roll followed by the switch as you indicate
is indeed the normal way to enter a slow roll. At low altitude however,
as a safety margin for airplanes like a T6 or a 51, I like using the
adverse yaw to negate the switch and give me just that little extra of
nose up in case something "unusual" happens like a bird strike for
example. You can't really see the difference from the ground unless it's
excessive so the roll axis still looks smooth and precise.
In other words, at low altitude you need that nose pointing up at all
times. The Blue Angels use nose down trim for the same reason. Inverted
they have a slight "edge" in case they are distracted for a nano-second
by something unexpected happening with the airplane.
Unless you are doing low altitude work, using coordinated rudder into
the roll entry then switching to top rudder is just fine.

--
Dudley Henriques

"Dudley Henriques" wrote in message
Unless you are doing low altitude work, using coordinated rudder into the
roll entry then switching to top rudder is just fine.

I took (a little) aerobatic instruction from Ken Hadden and he would call
out "kick the sky! kick the sky!"
as a way to coach you to switch to the top rudder input as the airplane
rolled.

Regards
Todd

Todd W. Deckard wrote:
"Dudley Henriques" wrote in message
Unless you are doing low altitude work, using coordinated rudder into the
roll entry then switching to top rudder is just fine.

I took (a little) aerobatic instruction from Ken Hadden and he would call
out "kick the sky! kick the sky!"
as a way to coach you to switch to the top rudder input as the airplane
rolled.

Regards
Todd


Each acro instructor will pick up little subtle ways of getting
something through to a student that can be easily remembered under
pressure. "Kick the sky" seems to be a good method of presentation for
your instructor.


--
Dudley Henriques