T-34 crash

Dave Hyde wrote:
How many g's are required for the "gentlemen's" ACM routinely flown
by these outfits?

In the T-34 accident last year, a video recording showed the aircraft
on the INSIDE of the turn (the one that didn't lose a wing) pulling 5
gees - in a turn. I have no idea what is required - but 5 gees with a
rolling component is excessive.

Saying and doing are two different animals. Since you seem
to give some import to this comment, how many g's did the
'student' apply as a result of the comment - asymmetric
or symmetric?

Enough to pull the wing off.

Dance around this all you want - these weekend warrior operations
account for a minority of the flight time of T-34's, but they account
for 100% of the lost wings. It's not the airplane - it's the
operation.

Michael

Michael wrote

In the T-34 accident last year, a video recording showed the aircraft
on the INSIDE of the turn (the one that didn't lose a wing) pulling 5
gees - in a turn.

So how many g's was the mishap airplane pulling?
The only correct answer you can give is "I don't know."

...how many g's did the
'student' apply as a result of the comment - asymmetric
or symmetric?

Enough to pull the wing off.

That's apparent - now was it below or above the limit?

Dance around this all you want...

No dancing here - I'm pointing out, with your help, that
you have little in the way of facts or experience, but
plenty of supposition and disdain for several parties
involved.

It's not the airplane - it's the operation.

Simply writing "ACM" on a flight card in the airplane
does not cause the wings to fall off. Was the stress
at failure above or below design limits? Until you can
answer that question factually and support it quantitatively
everything else is just throwing stones.

Dave 'innuendo' Hyde

Dave Hyde wrote:
In the T-34 accident last year, a video recording showed the
aircraft
on the INSIDE of the turn (the one that didn't lose a wing) pulling
5
gees - in a turn.

So how many g's was the mishap airplane pulling?
The only correct answer you can give is "I don't know."

Bzzt, wrong, but thanks for playing.

Since the accident aircraft was keeping up, and was on the outside of
the turn, the correct answer is more than five. That's simple physics.
And since it was in a turn, there had to be a rolling component
involved as well at some point.

Keep dancing.

Michael

"Michael" wrote in message
ups.com...

Since the accident aircraft was keeping up, and was on the outside of
the turn, the correct answer is more than five. That's simple
physics.

If you're saying that the aircraft "keeping up" on the outside of the
turn was at a higher g than the 5g's being pulled by the aircraft in
front and inside of him , you are mistaken.
Actually if the trailing aircraft was "keeping up" he would be at co
speed in the turn, and at co speed, the g would be the same on both
aircraft and the trailer would be the defender after 180 degrees of this
somewhat bad situation for the guy in back. This is why the attacking
aircraft can't be at the same g as the bandit and be "keeping up". The
trailer MUST have closure rate and a Ps advantage on the defender to
acheive an attack curve. This can be in a pursuit curve, usually a lag
curve at lower g with a higher attack velocity, or it can be obtained by
the use of cutoff or arcing inside the plane of turn of the defender. In
other words, the guy behind can't "keep up" by having a higher g. He
can't even keep up pulling the same g as the defender since this puts
them both in the same turn radius. The attacker must maintain a higher
attack velocity than the defender which means that in order to effect
closure and reduce angle off, he has to pull a lower g than the
defender.
Assuming both aircraft have the same Vc (corner velocity) which they do
as T34's , the only possible situation that would put the trailer at a
higher g then the defender as you have stated , would be if he was
pulling lead which would put him in a lead pursuit curve and inside the
plane of turn of the defender at a higher g....therefore no longer
"keeping up" so to speak.
Also, the attacker HAS to have a higher airspeed in the attack curve to
acheive nose/tail separation and angle off, which means, if he doesn't
pull higher g than the defender, HE MUST OVERSHOOT if he's in the plane
of turn of the defender. So if he's back there at all, he ain't at co
speed at the same g, and he has to be pulling a LOWER g, not a higher g
than the aircraft with which he's engaged.


Keep dancing.

Why so nasty to this poster? He's only asking a question. Hell, if
you're going to be nasty, at least give him the right answer :-)

Michael

yeah, I know; The ACM expert! :-)

Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/CFI Retired
for email; take out the trash

Dudley Henriques wrote...

Why so nasty to this poster? He's only asking a question. Hell, if
you're going to be nasty, at least give him the right answer :-)

Michael and I have discussed accident investigation techniques
and results both here and face-to-face. Let's just say we're
at opposite ends of the opinion yardstick. And I didn't take
it as particularly nasty.

Dave 'opinion poll' Hyde

Dudley

Long time no talk. Health not good.

You explaination in your post is confusing and in many cases wrong.

To hit a target you have to put the pipper on the aim point which
remains the same as long as the target maintains the same airspeed.
So you aim at the same point when you are 90 degrees or 10 degrees
off. Sight picture looks diffeent but aim point remains the same. Duck
hunters will understand this.

If you fall into trail (say 1000 feet behind target) and put the
pipper on the target you will miss. If you close until all you see in
the wind screen is target then you can point and shoot and kill. Many
of the high scoring Aces flew into that postion to get kills. Others
of course got most of their kills in a pursuit curve (higher angle
off).

If you are flying the same diameter circle as the target and not
closing then you will be pulling the same "g's" as the target. From
that positon to get a kill you have to decrease the diameter of circle
you are flying to get on the pipper on aim point and that makes you
pull more 'G's" than the target.

If you got a 'fur ball' going, then the vaying speed and aim point
causes the 'G' loading to vary through out the fight.

All that being said, I don't remember the latest accident being in a
combat simulation? Just upset training which should be get wings level
right sideup and then recover from dive. No rolling 'G's' in this.

Fly safe and very Merry Xmas to you and yours,

Big John
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~``


On Wed, 15 Dec 2004 04:52:11 GMT, "Dudley Henriques"
wrote:


"Michael" wrote in message
oups.com...

Since the accident aircraft was keeping up, and was on the outside of
the turn, the correct answer is more than five. That's simple
physics.

If you're saying that the aircraft "keeping up" on the outside of the
turn was at a higher g than the 5g's being pulled by the aircraft in
front and inside of him , you are mistaken.
Actually if the trailing aircraft was "keeping up" he would be at co
speed in the turn, and at co speed, the g would be the same on both
aircraft and the trailer would be the defender after 180 degrees of this
somewhat bad situation for the guy in back. This is why the attacking
aircraft can't be at the same g as the bandit and be "keeping up". The
trailer MUST have closure rate and a Ps advantage on the defender to
acheive an attack curve. This can be in a pursuit curve, usually a lag
curve at lower g with a higher attack velocity, or it can be obtained by
the use of cutoff or arcing inside the plane of turn of the defender. In
other words, the guy behind can't "keep up" by having a higher g. He
can't even keep up pulling the same g as the defender since this puts
them both in the same turn radius. The attacker must maintain a higher
attack velocity than the defender which means that in order to effect
closure and reduce angle off, he has to pull a lower g than the
defender.
Assuming both aircraft have the same Vc (corner velocity) which they do
as T34's , the only possible situation that would put the trailer at a
higher g then the defender as you have stated , would be if he was
pulling lead which would put him in a lead pursuit curve and inside the
plane of turn of the defender at a higher g....therefore no longer
"keeping up" so to speak.
Also, the attacker HAS to have a higher airspeed in the attack curve to
acheive nose/tail separation and angle off, which means, if he doesn't
pull higher g than the defender, HE MUST OVERSHOOT if he's in the plane
of turn of the defender. So if he's back there at all, he ain't at co
speed at the same g, and he has to be pulling a LOWER g, not a higher g
than the aircraft with which he's engaged.


Keep dancing.

Why so nasty to this poster? He's only asking a question. Hell, if
you're going to be nasty, at least give him the right answer :-)

Michael

yeah, I know; The ACM expert! :-)

Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/CFI Retired
for email; take out the trash

"Big John" wrote in message
...
Dudley

Long time no talk. Health not good.

You explaination in your post is confusing and in many cases wrong.

I think you're reading it wrong John. Read it again. We're saying
basically the same thing. See my inserts.



To hit a target you have to put the pipper on the aim point which
remains the same as long as the target maintains the same airspeed.
So you aim at the same point when you are 90 degrees or 10 degrees
off. Sight picture looks diffeent but aim point remains the same. Duck
hunters will understand this.

Basically, what you are describing here is a tracking solution.
Regardless of how you acheive positioning, as you slide the pipper up on
the target, the sight is compensating for gravity drop in the vertical
plane, velocity jump, which moves with the plane of symmerty of the
aircraft, and in the case of a gun solution, trajectory shift as well.
Pulling lead on a turning target requires a higher g and tighter radius
than the target. The factors that determine your ability to pull this
lead are dictated by your corner velocity vs the g already being pulled
in the turn by the advesary. Generally, you are in plane with a hot
pipper only as long as you can pull lead on the target. If the pipper
slides off the target, you're in overshoot.

If you fall into trail (say 1000 feet behind target) and put the
pipper on the target you will miss.

This is true. You must pull lead to obtain a tracking solution. You
can't do this in trail.....or "keeping up" as the man said :-)



If you close until all you see in
the wind screen is target then you can point and shoot and kill. Many
of the high scoring Aces flew into that postion to get kills.

This is true enough, but don't forget the differential attack velocity.
You can't go trail without matching g, and if you match g, you're
immediately matching turn at co speed. The aces who flew into the six
and fired, like Hartmann, did this while passing through in
overshoot..in other words, a snap shot, but at low angle off. You can't
sit in the saddle with matching g in a turning fight and fire. You'll
miss! If the target straightens out of the turn, you can saddle up and
nail him. A hard turning target is a whole different ballgame for a
saddle six shot like you're describing. Instead of just filling the
windshield between the frame supports like Hartmann did, you get a close
in snap shot as you pass through the six position, which can be very
effective. The Israiles did magnificent snap shooting during the six day
war, and re-wrote the book for the F4 in ACM.


Others
of course got most of their kills in a pursuit curve (higher angle
off).

Using manual ranging, this type of kill was quite common.

If you are flying the same diameter circle as the target and not
closing then you will be pulling the same "g's" as the target.

You can't fly the same radius circle as the opponent...at any time
during the pass.


From
that positon to get a kill you have to decrease the diameter of circle
you are flying to get on the pipper on aim point and that makes you
pull more 'G's" than the target.

Absolutely. This is pulling lead as I said before.

If you got a 'fur ball' going, then the vaying speed and aim point
causes the 'G' loading to vary through out the fight.

Correct. Generally, a "furball" will result in a decay in airspeed,
altitude, and Ps. It usually will put you in negative Ps if prolonged
against a hard turning opponent. Again, it's highly dependant on who's
flying what and where the fight is taking place in each aircraft's
envelope.

All that being said, I don't remember the latest accident being in a
combat simulation? Just upset training which should be get wings level
right sideup and then recover from dive. No rolling 'G's' in this.

Actually, this is a perfect setup for a rolling pullout. Also, I believe
the major issue with the T34 has involved the fantasy flights and not
upset training.

Fly safe and very Merry Xmas to you and yours,

Also to you and yours.

Bottom line John.
From reading your post, I can't see where we are differing in what each
of us is saying at all :-)

Dudley


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~``


On Wed, 15 Dec 2004 04:52:11 GMT, "Dudley Henriques"
wrote:


"Michael" wrote in message
roups.com...

Since the accident aircraft was keeping up, and was on the outside
of
the turn, the correct answer is more than five. That's simple
physics.

If you're saying that the aircraft "keeping up" on the outside of the
turn was at a higher g than the 5g's being pulled by the aircraft in
front and inside of him , you are mistaken.
Actually if the trailing aircraft was "keeping up" he would be at co
speed in the turn, and at co speed, the g would be the same on both
aircraft and the trailer would be the defender after 180 degrees of
this
somewhat bad situation for the guy in back. This is why the attacking
aircraft can't be at the same g as the bandit and be "keeping up". The
trailer MUST have closure rate and a Ps advantage on the defender to
acheive an attack curve. This can be in a pursuit curve, usually a lag
curve at lower g with a higher attack velocity, or it can be obtained
by
the use of cutoff or arcing inside the plane of turn of the defender.
In
other words, the guy behind can't "keep up" by having a higher g. He
can't even keep up pulling the same g as the defender since this puts
them both in the same turn radius. The attacker must maintain a higher
attack velocity than the defender which means that in order to effect
closure and reduce angle off, he has to pull a lower g than the
defender.
Assuming both aircraft have the same Vc (corner velocity) which they
do
as T34's , the only possible situation that would put the trailer at a
higher g then the defender as you have stated , would be if he was
pulling lead which would put him in a lead pursuit curve and inside
the
plane of turn of the defender at a higher g....therefore no longer
"keeping up" so to speak.
Also, the attacker HAS to have a higher airspeed in the attack curve
to
acheive nose/tail separation and angle off, which means, if he doesn't
pull higher g than the defender, HE MUST OVERSHOOT if he's in the
plane
of turn of the defender. So if he's back there at all, he ain't at co
speed at the same g, and he has to be pulling a LOWER g, not a higher
g
than the aircraft with which he's engaged.


Keep dancing.

Why so nasty to this poster? He's only asking a question. Hell, if
you're going to be nasty, at least give him the right answer :-)

Michael

yeah, I know; The ACM expert! :-)

Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/CFI Retired
for email; take out the trash

Dudley Henriques wrote a bunch of stuff about lead, lag,
and tracking.

That's al well and good, but in your case as with Michael's,
we don't really know what the mishap airplane was actually
doing - all that's been given here is a qualitative 'keeping
up.' Michael has extrapolated that to the extreme steady-state
welded-wing example and you have added the semi-steady-
state example of tracking techniques. You and I both know that
real-life 'keeping up', particularly in an ACM-type environment,
is never steady-state, and all the generalizations fall apart in
the specific, particularly when a limit case is experienced.
So...was the failure stress (STRESS, not normal acceleration)
over the spec value on the mishap airplane? The people shooting
down the investigation results should be prepared to answer this...
quantitatively.

Dave 'rhetorical' Hyde

Michael oglegroups.com...

Since the accident aircraft was keeping up, and was on the outside of
the turn, the correct answer is more than five. That's simple physics.
And since it was in a turn, there had to be a rolling component
involved as well at some point.

How accurate was the accelerometer? What was the load at the
time of failure,. As before, you don't know. You also don't
know if it was above or below the spec stress. The repetetive
theme of the thread is "you don't know". Neither do I, but I
don't claim to, nor do I attribute blame.

Dave 'popup' Hyde