Mid-Air Collisions

(Brad) wrote in message . com...
Here is some more to add to Paul's excellent post:

Paul and I had flown the earlier part of the day team flying for about
3.5 hours or so. We had worked our way from the local foothills and
eventually ended up about 30 miles away over the rugged snowy peaks at
the end of the Skykomish Valley; and the start of the Stevens Pass
highway. This was pretty good considering the day was somewhat windy
and the building high pressure was starting to affect the thermal
activity.

check out the following Powerpoint presentation regarding development of Swiss
anticollision devices for gliders.
www.tcw.ie/download/anticollision.ppt


Bruno

Paul

Thank you for your very honest posting. A major revelation is that you
believe that GPS/cockpit instrumentation was *not* the cause of the
incident.

Ian

"Tom Seim" wrote in message
om...
Your description of the accident was very articulate and sobering.

I would like to hear more about the bailout. In particular:

1. What was your approx. altitude (AGL) at collision.

Roughly 1000-1300' It's hard to say because I'm not sure if we collided
over this little shoulder that juts out from the ridge or out over the steet
terrain below, that drops 3000 feet very quickly.


2. How difficult was it for you to exit the glider and how much
altitude did you lose in the process.

Unknown, I blacked out momentarily, probably due to my head striking the
canopy, so I have no idea how much time elapsed between the collision and
when I began to egress the glider. It could have only been a second or two
because, my glider hit the ridge about 200 or 300 yards from Will's crash
site. See #4 for more detail. I would point out, due to my close proxmity
to the ground, if my canopy had not shattered due to my head and the force
of the collision, I may not have had time to unlatch it AND perform the rest
of the egress.


3. What was your attitude when you pulled the rip cord.

Approximately 500ft, I was under canopy 2 seconds or so before I landed in
the tree. I remember pulling the ripcord and seeing it come out of the
chute in my hand... As I wondered whether something was broken or not I
remember seeing cord and fabric flying out of the corner of my left eye. I
felt the tug of it open, I looked up to see it opening, I looked down and
saw trees everywhere, and then I was in one.


4. Did you have any problems separating from the glider.

It was probably in a spin of some sort due to the wing damage and I remember
really struggling to push myself out. At the time I thought it was the
horrendous wind blowing me back inside, but now I think it probably had more
to do with centripidal force from the glider's flight path. What I ended
up doing is reaching my left arm and elbow out over the back of the left
wing (This was a Libelle 201B) and I leveraged my body out of the cockpit
with that arm and my feet. I don't remember exactly how it happened that
my body rolled over the wing but, I imagine the nose down attitude combined
with the increasing airspeed helped flip me over the wing once my feet and
legs were free of the cockpit. I imagine I was just lucky that I didn't hit
the tail.


5. What brand of chute did you have.

The tag from the chute says Silver Parachute Sales & Service. I bought it
with the glider and took it to a local repacker who checked it out, said it
was in good shape, and repacked it for me. The Canopy was a Steerable
National Phanton 28' which I guess has the longer shrouds for a lower
descent rate and may have saved me a much harder landing. It may not have
mattered though, because I landed in a Hemlock which have very soft tops and
give quite easily. One of the amusing things I look back on now is this
strange, surreal sense of disappointment I had after landing in the tree
that I didn't have time to try steering the chute. The Harness was the
Original Softie Back 0247-S and was maufactured by Para-Phernalia.

I did talk to Allen Silver who runs or owns that above company and he
pointed me to a website and was helpful in providing some information that I
didn't know prior to using this rig. I should mention that I had NOT had
any training in egress or bail out procedures. What I did do is sit in the
glider and pretend I was going down and go through the motions a few times,
I just "thought" about getting out, so when the time came I didn't have to.
It paid off, my hands went right to the appropriate places and preformed
just the right functions. It was especially fortunate I did all this as it
was only my third flight in the Libelle 201B with that rig and belts.


6. Did you have any injuries landing in the trees.

Not that I could tell, I did discover my face injury from the canopy once I
was in the tree. I also discovered my legs were very bruised and sore,
probably from kicking the bottom of the instrument panel while I tried to
bail out.


7. What problems did you have getting down to the ground after landing
in the trees.

I was lucky as the trees were newer growth and smaller diameter, I was able
to use the harness as a swing and get over to another, smaller diameter tree
that I slide down like a pole. There were small twiggy branches that
helped slow my fall, but it wasn't bad. If I had been in much larger trees
with no lower branches and large trunks, I would have probably been stuck.


8. Did either glider have an ELT.

No, and though I may not shell out the bucks for a full size ELT in the
future, I most certainly will purchase the pocket models that can be carried
on one's person. It's easy for me to imagine a scenario where the glider
travels quite a distance from the bail out point and I'd rather have the ELT
on my person than in the glider. Also, I had a portable radio, but it was
hooked to a BNC cable for the ships antennae. If one doesn't have a
protable ELT, I couldn't recommend more just keeping the portable on your
person and buying a fixed ship radio.

thx,

Tom Seim
Richland, WA

A few more thoughts that a private email question spurred me to sha

We were almost exactly at 90 degrees to each others nose at the time of
collision. I could probably have looked 45 degrees to the left and not seen
him in peripheral vision because there was no relative change in his
position to mine. Despite our relative locations though, we had enough
closure for a serious collision. The other oddity; though he was banking
away from me, he was just at his point in the circle where my flight path
was tangent to the outside of his turn. Thus he probably had to look OVER
the high side of his cockpit to see me or perhaps I was even hidden under
his nose as he came around. Judging by his position when I heard his call
over the radio, he saw me in the former situation, probably because he at
first was looking for me in a turn behind him and not out in front.

I realize now that scanning from 100 to 80 degrees on either side of the
cockpit was something I almost never did outside of turns. When I would
make small course adjustments or was flying straight ahead, I think it was
rare for me to look farther than 60 degrees to the side. Also, when IN
turns I think I tend to look around the corner of my turn more often than
straight ahead, perhaps Will did the same thing. With an audio vario my
guess is a pilot might stop looking down to the instrument panel after
establishing a turn and centering the yaw string. If somebody was on a
tangent that would intercept a turn, they might appear right in front or
perhaps under the nose of the glider and stationary. His DG-400 surely had
a few knots over my Libelle, so it may very well have been one of those
situations mentioned in a previous post about lower performance glider
boxing in higher performance glider.

Paul

Bravo Paul, I am glad that someone who has experienced that
you just have, has the cojones to lay out the events
for the rest of us so that we can all put a little
pride aside and learn a little something. Hopefully
your comments will help the rest of us avoid a similar
experience. I am sure, in this newsgroup, your comments will
draw plenty of conjecture from the enlightened, but
from those of us who don't know it all. Thanks!jeff At 02:12 16 April 2004, Paul Adriance wrote:A few more thoughts that a private email question spurred
me to shaWe were almost exactly at 90 degrees to each others
nose at the time ofcollision. I could probably have looked 45 degrees
to the left and not seenhim in peripheral vision because there was no relative
change in hisposition to mine. Despite our relative locations
though, we had enoughclosure for a serious collision. The other oddity;
though he was bankingaway from me, he was just at his point in the circle
where my flight pathwas tangent to the outside of his turn. Thus he probably
had to look OVERthe high side of his cockpit to see me or perhaps I
was even hidden underhis nose as he came around. Judging by his position
when I heard his callover the radio, he saw me in the former situation,
probably because he atfirst was looking for me in a turn behind him and not
out in front.I realize now that scanning from 100 to 80 degrees
on either side of thecockpit was something I almost never did outside of
turns. When I wouldmake small course adjustments or was flying straight
ahead, I think it wasrare for me to look farther than 60 degrees to the
side. Also, when INturns I think I tend to look around the corner of my
turn more often thanstraight ahead, perhaps Will did the same thing. With
an audio vario myguess is a pilot might stop looking down to the instrument
panel afterestablishing a turn and centering the yaw string.
If somebody was on atangent that would intercept a turn, they might appear
right in front orperhaps under the nose of the glider and stationary.
His DG-400 surely hada few knots over my Libelle, so it may very well have
been one of thosesituations mentioned in a previous post about lower
performance gliderboxing in higher performance glider.Paul

Paul and Will's family have my sincere sympathy. What a horrible
tragedy to have to live through, and live with.

But if any good is to come out of such a horrible event, it is for the
rest of us to try and learn how we might reduce the chance of another
such tragedy. For that, Paul and the other posters have my gratitude.
A few thoughts on that topic:

1. While greater use of the radio probably would have prevented this
accident, no one has mentioned the pressure we all feel to minimize
such use so as to not interfere with other pilots who also need the
frequency. There just aren't enough air-to-air frequencies for all of
us to be in constant contact with nearby gliders on a busy day. Anyone
who uses 123.3 or 123.5 as much as they need to always know where
their flying buddy is will get chewed out for overuse of the
frequency.

But there is a solution. Get the people you fly with to get their ham
licenses and radios, or more simply and cheaply (but less range - but
hey, we're talking about midairs) the unlicensed FRS radios. I just
bought two of the latter for well under $100 at Costco since my most
frequent flying buddy has them. I'm also waiting for him to get his
ham license.

2. While, as noted, GPS can be a distraction if misused, it is also
invaluable for collision avoidance. If both gliders have the same
destination dialed in, they can give bearing and distance to quickly
determine when they are in close proximity to one another. Visual
references are much less precise.

3. The European PPT post at first left me thinking, "not much use",
but as I'll explain below, more thought led me to think it may have a
lot of merit. I, as many others, have thought that a low cost device
like that described was a much better approach than the expensive ones
being pursued by the powers that be. If it was portable, there would
be no need for a 337 or other paperwork.

The big problem, and the one that made me have an initial negative
reaction to the utility of the idea, is the "chicken and egg problem."
The device is of no use until a significant fraction of the fleet has
one, and who wants one before it is useful?

So what made me change my mind? The realization that gliders, or other
planes, that fly in close proximity to one another could benefit
immensely from the device even if no one else had it but those two
aircraft. If it were available for a few hundred dollars (and in large
quantity production there's no reason they should cost even that much
-- except for the possible liability and patent issues mentioned in
the PPT slides), I suspect I could convince my frequent flying buddies
to get them too. And, maybe that's the way to get over the chicken and
egg problemfor them to be useful for general midair collision
avoidance. If we ever reached the point that a significant fraction of
the whole fleet bought them to avoid hitting their flying buddies,
then they'd become even more useful.

4. The last point has to do with complacency. When put that way, it
sounds too mundane. We all know the danger of compacency. Or do we?
On reflecting on this thread, I realized I needed to be less
complacent in ways that hadn't hit me before.

I have had a similar situation to Paul and Will's, where I was flying
in close proximity to a friend, one of us moved away, neither of us
had the other in sight, I was concerned, but felt that one more radio
call just to confirm that all was OK would sound compulsive or
amateurish. After all, I've been in that situation many times, with no
ill consequences. And none of the other guys flying close to one
another are constantly checking. Just listen to the frequency. So I
didn't call on the radio for fear of becoming a nuisance either to my
friend or the others on the frequency. But after being a part of this
thread, I am committing to being extra wary of doing that again. One
of the problems with complacency is that it wears many disguises, in
this case that of the competent pilot. In this disguise, we believe
that only a rank beginner or scaredy-cat would be constantly giving in
to his fears of "where did he go" and hitting the PTT each time.

Hoping these thoughts are of some help.

Martin

I'm sure almost every RAS reader has read every word of Paul's account
because we all have been in the same situation numerous times and could see
the same thing happen to us at any moment.

I have a lot of soaring books but it is interesting that little is written
or formally taught about this aspect of soaring. Outside of the basic rule
of gaggle flying in the same direction as others, I think we need a stamdard
protocol for any proximity or formation flying which we all rouinely do.
Outside of stall/spin in the pattern, mid-airs during proximit/formation
flying (including gaggles) is likely the next most dangerous situation we
activily place ourselves in.

1. What is the safest way to enter a gaggle, and what are the most unsafe
ways?
2. If you lose sight of another glider that you are gaggling with, should
you keep thermalling or head away? (assume no radio available)
3. What is the safest way to exit a gaggle, and what are the most unsafe
ways?
4. Pair flying - best practices and worst practices ....?


Let's express our best ideas here and perhaps this too will save lives.

I do know that these recent events have caused members of our local club to
immediately begin studying our local methods and habits, which I think this
activity will result in some pretty healthy positive changes.

One more thought about Mid Air Collisions.

Next time you are belting along under a cloud street
at 90 - 100 Knots plus.

How far away will the other glider be, doing the same
thing in the opposite direction, when you see it, and
how long have you got to make the right decision with
a closing speed of 200 knots!!!!!!!

At 09:54 16 April 2004, Tom Rent wrote:
I'm sure almost every RAS reader has read every word
of Paul's account
because we all have been in the same situation numerous
times and could see
the same thing happen to us at any moment.

I have a lot of soaring books but it is interesting
that little is written
or formally taught about this aspect of soaring. Outside
of the basic rule
of gaggle flying in the same direction as others, I
think we need a stamdard
protocol for any proximity or formation flying which
we all rouinely do.
Outside of stall/spin in the pattern, mid-airs during
proximit/formation
flying (including gaggles) is likely the next most
dangerous situation we
activily place ourselves in.

1. What is the safest way to enter a gaggle, and what
are the most unsafe
ways?
2. If you lose sight of another glider that you are
gaggling with, should
you keep thermalling or head away? (assume no radio
available)
3. What is the safest way to exit a gaggle, and what
are the most unsafe
ways?
4. Pair flying - best practices and worst practices
....?


Let's express our best ideas here and perhaps this
too will save lives.

I do know that these recent events have caused members
of our local club to
immediately begin studying our local methods and habits,
which I think this
activity will result in some pretty healthy positive
changes.

There's a lot that can be written about gaggle flying, (And I hope will be.)
but I'd like to cut to a small part of it. Thermaling with one other
glider.

If the other pilot is highly skilled, this can be a very beautiful
experience. Two pilots who really know the techniques will position
themselves on opposite sides of the circle from each other while flying at
the same bank angle and airspeed while maintaining the same center. The
other glider will seem to hang motionless in mid-air 300 feet away as the
world whirls about. Eye contact is maintained between the two pilots.

It always surprises me when I hear objections to this like, "it's dangerous
to be that close to another glider, it scares me". In fact, this is the
safest configuration to be thermaling with another glider. There's just no
way that a collision can occur if this formation is maintained. Each glider
is on a reciprocal heading and separated by 300 feet or more. Either glider
can roll out and fly away at any time and the separation will increase.

In addition, the other glider is a far better indication of lift than any
vario. If he climbs in relation to you, then the circle needs to be moved
that direction. To make that move and maintain the relative position of the
gliders, he will not make a correction, that is up to you. He knows that
you saw him climb and that you will move the circle towards the lift, he
will follow. Roll out on a heading towards where you saw him climb, fly for
three seconds and roll back in and he will do the same and the formation is
maintained even as it is shifted toward the stronger lift. If you are the
one that hits a strong core, wait for the other pilot to make a move, then
follow.

All to often, I see the other glider roll out when he hits the core of the
thermal. This is a really dumb move since he in now flying directly away
from the best lift. Now, if I want to maintain the formation, I will have
to fly out of the thermal with him. Or, timid pilots will simply move away
one circle diameter and try to work the broken lift there. Now you meet him
head-on once every turn while losing sight of him in between - this IS
dangerous.

I recently saw four gliders at the same altitude flying a "four leaf clover"
pattern. They all met at intersecting angles each turn. I didn't enter
that gaggle.

So, the point of the above ramble is that not only should you turn in the
same direction as the other glider, also turn about the same center point.

Bill Daniels

"Trevor Nash" wrote in message
...
One more thought about Mid Air Collisions.

Next time you are belting along under a cloud street
at 90 - 100 Knots plus.

How far away will the other glider be, doing the same
thing in the opposite direction, when you see it, and
how long have you got to make the right decision with
a closing speed of 200 knots!!!!!!!

At 09:54 16 April 2004, Tom Rent wrote:
I'm sure almost every RAS reader has read every word
of Paul's account
because we all have been in the same situation numerous
times and could see
the same thing happen to us at any moment.

I have a lot of soaring books but it is interesting
that little is written
or formally taught about this aspect of soaring. Outside
of the basic rule
of gaggle flying in the same direction as others, I
think we need a stamdard
protocol for any proximity or formation flying which
we all rouinely do.
Outside of stall/spin in the pattern, mid-airs during
proximit/formation
flying (including gaggles) is likely the next most
dangerous situation we
activily place ourselves in.

1. What is the safest way to enter a gaggle, and what
are the most unsafe
ways?
2. If you lose sight of another glider that you are
gaggling with, should
you keep thermalling or head away? (assume no radio
available)
3. What is the safest way to exit a gaggle, and what
are the most unsafe
ways?
4. Pair flying - best practices and worst practices
....?


Let's express our best ideas here and perhaps this
too will save lives.

I do know that these recent events have caused members
of our local club to
immediately begin studying our local methods and habits,
which I think this
activity will result in some pretty healthy positive
changes.

I'll tell ya, I use the radio and stomp the ground
controller at towered fields sometimes for collision avoidance.

I've had several near misses, and seen one guy
flip his plane in front of me because I was too
timid to get on freq and warn him we were about
to collide. I was in disbelief that he
wasn't seeing me and avoiding me. I'd say get on the
radio and use it per your judgement, and ignore the
critics. You're a pilot, not an actor in a bad play.

I'd also say LOUDLY that if it helps me to
use some other freq. than 123.3 or CTAF or
whatever for my formation flight, I do it.
I also have a personal limitation that I won't
fly glider formation without an audio vario, and I
casually slink away when someone joins my thermal...

It doesn't mean I don't like the other guy,
I'm just not that great at multitasking...

In article ,
Martin Hellman wrote:
Paul and Will's family have my sincere sympathy. What a horrible
tragedy to have to live through, and live with.

But if any good is to come out of such a horrible event, it is for the
rest of us to try and learn how we might reduce the chance of another
such tragedy. For that, Paul and the other posters have my gratitude.
A few thoughts on that topic:

1. While greater use of the radio probably would have prevented this
accident, no one has mentioned the pressure we all feel to minimize
such use so as to not interfere with other pilots who also need the
frequency. There just aren't enough air-to-air frequencies for all of
us to be in constant contact with nearby gliders on a busy day. Anyone
who uses 123.3 or 123.5 as much as they need to always know where
their flying buddy is will get chewed out for overuse of the
frequency.

But there is a solution. Get the people you fly with to get their ham
licenses and radios, or more simply and cheaply (but less range - but
hey, we're talking about midairs) the unlicensed FRS radios. I just
bought two of the latter for well under $100 at Costco since my most
frequent flying buddy has them. I'm also waiting for him to get his
ham license.

2. While, as noted, GPS can be a distraction if misused, it is also
invaluable for collision avoidance. If both gliders have the same
destination dialed in, they can give bearing and distance to quickly
determine when they are in close proximity to one another. Visual
references are much less precise.

3. The European PPT post at first left me thinking, "not much use",
but as I'll explain below, more thought led me to think it may have a
lot of merit. I, as many others, have thought that a low cost device
like that described was a much better approach than the expensive ones
being pursued by the powers that be. If it was portable, there would
be no need for a 337 or other paperwork.

The big problem, and the one that made me have an initial negative
reaction to the utility of the idea, is the "chicken and egg problem."
The device is of no use until a significant fraction of the fleet has
one, and who wants one before it is useful?

So what made me change my mind? The realization that gliders, or other
planes, that fly in close proximity to one another could benefit
immensely from the device even if no one else had it but those two
aircraft. If it were available for a few hundred dollars (and in large
quantity production there's no reason they should cost even that much
-- except for the possible liability and patent issues mentioned in
the PPT slides), I suspect I could convince my frequent flying buddies
to get them too. And, maybe that's the way to get over the chicken and
egg problemfor them to be useful for general midair collision
avoidance. If we ever reached the point that a significant fraction of
the whole fleet bought them to avoid hitting their flying buddies,
then they'd become even more useful.

4. The last point has to do with complacency. When put that way, it
sounds too mundane. We all know the danger of compacency. Or do we?
On reflecting on this thread, I realized I needed to be less
complacent in ways that hadn't hit me before.

I have had a similar situation to Paul and Will's, where I was flying
in close proximity to a friend, one of us moved away, neither of us
had the other in sight, I was concerned, but felt that one more radio
call just to confirm that all was OK would sound compulsive or
amateurish. After all, I've been in that situation many times, with no
ill consequences. And none of the other guys flying close to one
another are constantly checking. Just listen to the frequency. So I
didn't call on the radio for fear of becoming a nuisance either to my
friend or the others on the frequency. But after being a part of this
thread, I am committing to being extra wary of doing that again. One
of the problems with complacency is that it wears many disguises, in
this case that of the competent pilot. In this disguise, we believe
that only a rank beginner or scaredy-cat would be constantly giving in
to his fears of "where did he go" and hitting the PTT each time.

Hoping these thoughts are of some help.

Martin


--

------------+
Mark Boyd
Avenal, California, USA