Hey Dudley, detailed analysis of these?

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 message
...
Bertie the Bunyip wrote:
http://www.youtube.com/watch?v=F4_iJ...eature=related

http://www.youtube.com/watch?v=ZN1lC...eature=related

http://www.youtube.com/watch?v=9txDhi5wC2A

Have my own notions, but would be interested from a pros viewpoint. I'm
assuming that mechanical was not a factor in any of these, BTW.Might have
been, but it appears that in each case the pilot went in with no commital
gates and no escape route. Bertie

Can't say much about the Extra (at least it looked like an Extra) but the
Hurricane and the King Cobra are accidents I've been involved in with
safety discussions within the war bird demonstration community.

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.

What was his "out" once he was inverted and slow?

I assume the proper recovery is to pull back the power to a manageable
level, unload the airplane, and get the nose below the horizon in order to
build some airspeed. Once the airplane is flying again, feed in the power
while rolling level, then pull...



The Hurricane looks like it will come down to a simple brain fart. The guy
was very qualified and had experience. So far it looks like he simply
committed to a Split S below his minimum AGL parameter for the Hurricane.
This one is very similar to the Thunderbird F16 accident at Mountain Home
AFB where the team lost a Viper. Brain fart!


--
Dudley Henriques

"Kyle Boatright" wrote in
:




What was his "out" once he was inverted and slow?

I assume the proper recovery is to pull back the power to a manageable
level, unload the airplane, and get the nose below the horizon in
order to build some airspeed. Once the airplane is flying again, feed
in the power while rolling level, then pull...



Yeah, exactly. Can't see any other way out at the top, but I would have
thought he should have recognised the mess a lot earlier, i.e., at or
before reaching 90deg.
Looks like he was braving it out for the benefit of the crowd.

A bit like this guy..

http://www.youtube.com/watch?v=MUzjLxqHy5g

The show must go on, huh?

Bertie

"Bertie the Bunyip" wrote in message
.. .
"Kyle Boatright" wrote in
:




What was his "out" once he was inverted and slow?

I assume the proper recovery is to pull back the power to a manageable
level, unload the airplane, and get the nose below the horizon in
order to build some airspeed. Once the airplane is flying again, feed
in the power while rolling level, then pull...



Yeah, exactly. Can't see any other way out at the top, but I would have
thought he should have recognised the mess a lot earlier, i.e., at or
before reaching 90deg.
Looks like he was braving it out for the benefit of the crowd.

A bit like this guy..

http://www.youtube.com/watch?v=MUzjLxqHy5g

The show must go on, huh?

Bertie

The strange thing about the Yak near-pancake is that the guy comes over the
top with plenty of airspeed, gets the nose down, and then doesn't pull
enough G's until very late when he's past the vertical. Another quarter or
half G after he'd gotten the nose down and he wouldn't have had a memorable
recovery.

KB

"Kyle Boatright" wrote in
:


"Bertie the Bunyip" wrote in message
.. .
"Kyle Boatright" wrote in
:




What was his "out" once he was inverted and slow?

I assume the proper recovery is to pull back the power to a
manageable level, unload the airplane, and get the nose below the
horizon in order to build some airspeed. Once the airplane is flying
again, feed in the power while rolling level, then pull...



Yeah, exactly. Can't see any other way out at the top, but I would
have thought he should have recognised the mess a lot earlier, i.e.,
at or before reaching 90deg.
Looks like he was braving it out for the benefit of the crowd.

A bit like this guy..

http://www.youtube.com/watch?v=MUzjLxqHy5g

The show must go on, huh?

Bertie

The strange thing about the Yak near-pancake is that the guy comes
over the top with plenty of airspeed, gets the nose down, and then
doesn't pull enough G's until very late when he's past the vertical.
Another quarter or half G after he'd gotten the nose down and he
wouldn't have had a memorable recovery.



Yes, well that;'s all in the name of getting it close enough to make it
spectacular for the crowd of course.

This guy was less lucky..

http://www.youtube.com/watch?v=ifoHKZw_JQs



Bertie

Kyle Boatright wrote:
"Bertie the Bunyip" wrote in message
.. .
"Kyle Boatright" wrote in
:



What was his "out" once he was inverted and slow?

I assume the proper recovery is to pull back the power to a manageable
level, unload the airplane, and get the nose below the horizon in
order to build some airspeed. Once the airplane is flying again, feed
in the power while rolling level, then pull...


Yeah, exactly. Can't see any other way out at the top, but I would have
thought he should have recognised the mess a lot earlier, i.e., at or
before reaching 90deg.
Looks like he was braving it out for the benefit of the crowd.

A bit like this guy..

http://www.youtube.com/watch?v=MUzjLxqHy5g

The show must go on, huh?

Bertie

The strange thing about the Yak near-pancake is that the guy comes over the
top with plenty of airspeed, gets the nose down, and then doesn't pull
enough G's until very late when he's past the vertical. Another quarter or
half G after he'd gotten the nose down and he wouldn't have had a memorable
recovery.

KB


This is why the top gate is so important. You only have so much g you
can pull on the back side depending on the altitude and airspeed you
have when you initiate the down line. Pull too hard and you take the
airplane into drag rise then into high speed stall. Even into drag rise
you can have so much g on the airplane it denies you recovery room.
The Yak clip has been widely distributed in the Warbird community. The
truth is it just doesn't get any closer than this guy had it with a walk
away in your future.
DH

--
Dudley Henriques