Glider Crash - Minden?

"kirk.stant" wrote in message
oups.com...

Plus, 20 seconds is an eternity when it comes to getting out of the
way.

I asked this question several times, and never saw a convincing answer:
exactly how do you use even the 20 seconds if you have them to avoid
something coming at you at 300 (or, it was suggested, possibly much more)
knots? If you start in a thermalling glider at minimum sink speed, you can't
seem to run fast enough far enough given the rate of closure -- and the lack
of time to estimate relative motion precisely enough. We don't have
targeting radars in most of the gliders (not sure about Space Shuttle
though).
--
Yuliy

Yuliy Gerchikov wrote:
"kirk.stant" wrote in message
oups.com...

Plus, 20 seconds is an eternity when it comes to getting out of the
way.

I asked this question several times, and never saw a convincing answer:
exactly how do you use even the 20 seconds if you have them to avoid
something coming at you at 300 (or, it was suggested, possibly much more)
knots?

Stop turning and stick the nose down steeply at the same time.

That's about the quickest way to exit a given volume of air that I can
think of if you're starting from a low airspeed. I'll be interested to
hear of anything that would be faster and/or of something what would
work if you're too low to dive away from the threat.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

If you are on a collision course, how are you going to know whether going
down is the right solution? He might be 50 ft below you, and you are going
to dive right into him. Or he might also decide to descend.

This brings to mind an interesting suggestion that I was taught when I got
my power license about avoiding collisions with birds: Always climb, as the
birds will tend to dive.

Mike Schumann

"Martin Gregorie" wrote in message
...
Yuliy Gerchikov wrote:
"kirk.stant" wrote in message
oups.com...

Plus, 20 seconds is an eternity when it comes to getting out of the
way.

I asked this question several times, and never saw a convincing answer:
exactly how do you use even the 20 seconds if you have them to avoid
something coming at you at 300 (or, it was suggested, possibly much more)
knots?

Stop turning and stick the nose down steeply at the same time.

That's about the quickest way to exit a given volume of air that I can
think of if you're starting from a low airspeed. I'll be interested to
hear of anything that would be faster and/or of something what would work
if you're too low to dive away from the threat.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Mike Schumann wrote:
If you are on a collision course, how are you going to know whether going
down is the right solution? He might be 50 ft below you, and you are going
to dive right into him. Or he might also decide to descend.

Or you could just sit there with your eyes closed and do nothing, if
you have trouble making decisions. If you don't have the eye to know
what is the best move fairly quickly, almost instinctively, either
aviation is not for you, or else you need more hours in the air with
an experienced PIC. Get into the ball sports where an appreciation for
spatial relationships, hand-eye coordination, relative motion on all
planes, and accelerations is programmed into your brain -- though this
is best begun at a very early age.

---

Going down is good if you have the space; turning can work -- I have
most often done both; going up is a very limited option in a glider so
it's here that your timing and judgment are most critical.

If I had to suggest a rule of thumb, it would be to maneuver to a
position behind and below the traffic, and do not delay. The most
natural tendency seems to be to go up as an initial fright response,
so I would anticipate the other pilot will do that, if anything. By
the time you have identified the threat as necessitating an avoidance
reaction and begun your maneuver, his opportunity to make the
situation either better or worse has probably already been
considerably reduced. Of course there is always somebody out there who
is both slow to react and also tends to make exactly the wrong move.
But, if you are doing your part in the see-and-avoid dance you should
already have solved both his problem and yours. Early awareness goes a
long way toward simplifying the decision and enhancing your execution.


This brings to mind an interesting suggestion that I was taught when I got
my power license about avoiding collisions with birds: Always climb, as the
birds will tend to dive.

The birds don't always dive, I promise you. If they are as good at
see-and-avoid as they should be, they frequently do so. Some of them
aren't any better than some of us, however, when it comes to traffic
awareness. The lone hunters tend to be the sharpest, not surprisingly.
The flockers, not so much.


Jack

My point is not to try to avoid the collision, but show how big of a problem
it is when you get too close to some fast iron. It really gets to be
problematic to figure out what the best evasive maneuver is when you have a
very high closure rate.

The best solution is to try to avoid getting into this situation in the 1st
place. Having an operational transponder would be a good way to start.

Mike Schumann

"588" wrote in message
t...
Mike Schumann wrote:
If you are on a collision course, how are you going to know whether going
down is the right solution? He might be 50 ft below you, and you are
going to dive right into him. Or he might also decide to descend.

Or you could just sit there with your eyes closed and do nothing, if you
have trouble making decisions. If you don't have the eye to know what is
the best move fairly quickly, almost instinctively, either aviation is not
for you, or else you need more hours in the air with an experienced PIC.
Get into the ball sports where an appreciation for spatial relationships,
hand-eye coordination, relative motion on all planes, and accelerations is
programmed into your brain -- though this is best begun at a very early
age.

---

Going down is good if you have the space; turning can work -- I have most
often done both; going up is a very limited option in a glider so it's
here that your timing and judgment are most critical.

If I had to suggest a rule of thumb, it would be to maneuver to a position
behind and below the traffic, and do not delay. The most natural tendency
seems to be to go up as an initial fright response, so I would anticipate
the other pilot will do that, if anything. By the time you have identified
the threat as necessitating an avoidance reaction and begun your maneuver,
his opportunity to make the situation either better or worse has probably
already been considerably reduced. Of course there is always somebody out
there who is both slow to react and also tends to make exactly the wrong
move. But, if you are doing your part in the see-and-avoid dance you
should already have solved both his problem and yours. Early awareness
goes a long way toward simplifying the decision and enhancing your
execution.


This brings to mind an interesting suggestion that I was taught when I
got my power license about avoiding collisions with birds: Always climb,
as the birds will tend to dive.

The birds don't always dive, I promise you. If they are as good at
see-and-avoid as they should be, they frequently do so. Some of them
aren't any better than some of us, however, when it comes to traffic
awareness. The lone hunters tend to be the sharpest, not surprisingly. The
flockers, not so much.


Jack

Mike Schumann wrote:
My point is not to try to avoid the collision, but show how big of a problem
it is when you get too close to some fast iron. It really gets to be
problematic to figure out what the best evasive maneuver is when you have a
very high closure rate.

The best solution is to try to avoid getting into this situation in the 1st
place. Having an operational transponder would be a good way to start.


Start with PCAS it's cheaper, uses less power, and helps you control
your own destiny -- if you only have room for one unit. However, the
transponder/PCAS combination gives you everything you need to avoid
the scary big fast airplanes, AND the friendly little gliders in your
own club which are the ships you are most likely to hit. If all
gliders were so equipped we would all be safer.

Stall/spin in the pattern, midair anywhere -- these are the things
that kill glider pilots.

I suspect that after a pilot has flown with PCAS for awhile and has
come to realize how much traffic there is that he was not aware of
before, that pilot will be even more likely to want the transponder, too.


Jack

Mike Schumann wrote:
If you are on a collision course, how are you going to know whether going
down is the right solution? He might be 50 ft below you, and you are going
to dive right into him. Or he might also decide to descend.

If you need to get out from in front while thermalling, you'll need some
more airspeed to do so and that means lowering the nose to accelerate
while, hopefully, turning to aim off to one side of him.

The opposition has first to see you in order to decide to descend. If we
assign equal probabilities to him climbing, turning or diving then
anything you do to move away from his current course has a 75% chance of
being right.

Now lets be generous and give him a 50% chance of seeing you.
Probabilities multiply when they are combined, so that gives you an 87%
chance of being right.

This brings to mind an interesting suggestion that I was taught when I got
my power license about avoiding collisions with birds: Always climb, as the
birds will tend to dive.

That's only useful if you have an engine or airspeed. If you're
thermalling and try that you'll end up descending about 2 seconds later
and, if the opposition saw you pull up, he'll be down there waiting for
you. Besides, if he read the same book you're quoting he'll be more
likely to pull up than to dive.

In any case, you didn't say what you'd do, so I'll ask again. What would
you do that's better than diving out of the way?


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

In article , Martin Gregorie
writes
Mike Schumann wrote:
If you are on a collision course, how are you going to know whether going
down is the right solution? He might be 50 ft below you, and you are going
to dive right into him. Or he might also decide to descend.

If you need to get out from in front while thermalling, you'll need some
more airspeed to do so and that means lowering the nose to accelerate
while, hopefully, turning to aim off to one side of him.

The opposition has first to see you in order to decide to descend. If we
assign equal probabilities to him climbing, turning or diving then
anything you do to move away from his current course has a 75% chance of
being right.

Now lets be generous and give him a 50% chance of seeing you.
Probabilities multiply when they are combined, so that gives you an 87%
chance of being right.

This brings to mind an interesting suggestion that I was taught when I got
my power license about avoiding collisions with birds: Always climb, as the
birds will tend to dive.

That's only useful if you have an engine or airspeed. If you're
thermalling and try that you'll end up descending about 2 seconds later
and, if the opposition saw you pull up, he'll be down there waiting for
you. Besides, if he read the same book you're quoting he'll be more
likely to pull up than to dive.

In any case, you didn't say what you'd do, so I'll ask again. What would
you do that's better than diving out of the way?


Most of the threats round these parts find it a lot easier to
avoid you at the last second by pulling up, so I reckon Martin's advice
is the best going.

One day about 15 years ago I was downwind to land on 03 in the
tug. I saw an A-10 passing west to east about at 500ft over the approach
to this runway. Of course, he would be long gone by the time I got
there, so no problem.

When I landed, people rushed up and said "Did you see him?"
"Who?"
"The A-10"
"Oh, yes, but he was half a mile away over the end of the
airfield"
"No, not him. The other one, which we saw screaming towards you
when you were downwind. He must have seen you at the last moment, he
pulled up and missed you by about 5 feet. We thought we'd be looking to
get a new tug."

I never saw the second A-10. But I'm glad they all went home
when the cold war ended.


--
Mike Lindsay

Assigning equal probabilities won't always work. In the case of the Hawker
collision, the jet was descending, so diving would not have increased
separation as fast as climbing. In that particular region, jets are more
likely to be descending than climbing, so maybe the choice should be
influenced by what one knows about likely traffic in the area. South of
Reno, climb. North of Reno, dive. 'Course, that depends on which way ATC is
directing traffic... which is why Minden's glider educational materials tell
us to listen to ATC once in a while.

But that aside, on average it seems to me that (in a glider) diving would be
better because one will accelerate over time, increasing the distance from
where one started out. Zooming would not be as effective because speed will
decay, so the separation will initially grow but then will not grow so much.
Then one will either have to stay up there or descend back down through the
original altitude.

Since both pilots are nearly equally likely to choose climbing or diving,
leaving a 50% chance of ending up near each others' altitude, it seems to me
that diverting horizontally 90 degrees (perpendicular to the approaching
aircraft's heading) will help just as much as as changing altitude. Again,
both pilots could choose to turn the same way, so a 50% chance of still
being on a collision course. So turn AND climb/dive, and you end up with
more like a 25% chance of being in each others' way.

Roger (who's only had close encounters of the feathered kind)

"Martin Gregorie" wrote in message
...
Mike Schumann wrote:
If you are on a collision course, how are you going to know whether
going
down is the right solution? He might be 50 ft below you, and you are
going
to dive right into him. Or he might also decide to descend.

If you need to get out from in front while thermalling, you'll need some
more airspeed to do so and that means lowering the nose to accelerate
while, hopefully, turning to aim off to one side of him.

The opposition has first to see you in order to decide to descend. If we
assign equal probabilities to him climbing, turning or diving then
anything you do to move away from his current course has a 75% chance of
being right.

Now lets be generous and give him a 50% chance of seeing you.
Probabilities multiply when they are combined, so that gives you an 87%
chance of being right.

This brings to mind an interesting suggestion that I was taught when I
got
my power license about avoiding collisions with birds: Always climb, as
the
birds will tend to dive.

That's only useful if you have an engine or airspeed. If you're
thermalling and try that you'll end up descending about 2 seconds later
and, if the opposition saw you pull up, he'll be down there waiting for
you. Besides, if he read the same book you're quoting he'll be more
likely to pull up than to dive.

In any case, you didn't say what you'd do, so I'll ask again. What would
you do that's better than diving out of the way?


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Considering that the glider in question was in a left thermalling turn, that
the pilot caught just a brief glimpse of the inbound jet, just enough to
identify it as having two engines, before it tore into his glider, and that
the Hawker hit his upper wing about mid-span (or so I'm told), pulling up
may not have been such a good idea (g).

As someone else posted, most power pilots are trained to pull up for birds,
as the bird will invariably fold its wings and dive. I'd venture to say that
absent definitive altitude information about the threat, most power pilots
will pull up to avoid an impact.

My choice goes to diving to avoid a collision while flying a glider. If one
is thermalling at a relatively low speed, there's not going to be a lot of
energy to climb much, or fast.

bumper


"Roger Worden" wrote in message
. net...
Assigning equal probabilities won't always work. In the case of the Hawker
collision, the jet was descending, so diving would not have increased
separation as fast as climbing. In that particular region, jets are more
likely to be descending than climbing, so maybe the choice should be
influenced by what one knows about likely traffic in the area. South of
Reno, climb. North of Reno, dive. 'Course, that depends on which way ATC
is
directing traffic... which is why Minden's glider educational materials
tell
us to listen to ATC once in a while.

But that aside, on average it seems to me that (in a glider) diving would
be
better because one will accelerate over time, increasing the distance from
where one started out. Zooming would not be as effective because speed
will
decay, so the separation will initially grow but then will not grow so
much.
Then one will either have to stay up there or descend back down through
the
original altitude.

Since both pilots are nearly equally likely to choose climbing or diving,
leaving a 50% chance of ending up near each others' altitude, it seems to
me
that diverting horizontally 90 degrees (perpendicular to the approaching
aircraft's heading) will help just as much as as changing altitude. Again,
both pilots could choose to turn the same way, so a 50% chance of still
being on a collision course. So turn AND climb/dive, and you end up with
more like a 25% chance of being in each others' way.

Roger (who's only had close encounters of the feathered kind)

"Martin Gregorie" wrote in message
...
Mike Schumann wrote:
If you are on a collision course, how are you going to know whether
going
down is the right solution? He might be 50 ft below you, and you are
going
to dive right into him. Or he might also decide to descend.

If you need to get out from in front while thermalling, you'll need some
more airspeed to do so and that means lowering the nose to accelerate
while, hopefully, turning to aim off to one side of him.

The opposition has first to see you in order to decide to descend. If we
assign equal probabilities to him climbing, turning or diving then
anything you do to move away from his current course has a 75% chance of
being right.

Now lets be generous and give him a 50% chance of seeing you.
Probabilities multiply when they are combined, so that gives you an 87%
chance of being right.

This brings to mind an interesting suggestion that I was taught when I
got
my power license about avoiding collisions with birds: Always climb,
as
the
birds will tend to dive.

That's only useful if you have an engine or airspeed. If you're
thermalling and try that you'll end up descending about 2 seconds later
and, if the opposition saw you pull up, he'll be down there waiting for
you. Besides, if he read the same book you're quoting he'll be more
likely to pull up than to dive.

In any case, you didn't say what you'd do, so I'll ask again. What would
you do that's better than diving out of the way?


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |