Aug 6th B738 and Glider Near Miss. Frankfurt

On Oct 16, 11:47*am, "Matt Herron Jr." wrote:
On Oct 12, 12:00*pm, India November wrote:





On Oct 12, 6:25*pm, Darryl Ramm wrote:

On Oct 12, 2:08*am, John Smith wrote:

Darryl Ramm wrote:

---

Moving topic somewhat but I want to make the point that we've lost
several airliners full of passengers in fatal-midair collisions with
light-aircraft and the response to that was largely transponders and
TCAS/ACAS. And gliders operating near high density airline and fast
jet traffic without transponders are effectively bypassing that
evolution. I worry that human nature and perception of risks can allow
apparent reduction of risks in situation because we don't perceive
those rare but critical accidents happening frequently enough to
register as practical risks even if they have catastrophic outcomes. I
start my talks on collision avoidance with the following (USA centric
information). There are similar fatal mid-air collisions outside the
USA.

Allegheny 853
MD DC-9 vs. Piper Cherokee
Fairield, Indiana 1969 -- 83 killed

Pacific Southwest 182
Boeing 727 vs. Cessna 172
San Diego, California 1978 -- 144 killed

Aeroméxico 498 (the mid-air that lead to Mode C transponder and TCAS
carriage requirements in the USA)
MD DC-9 vs. Piper Cherokee
Cerritos, California 1986 -- 82 killed, 8 injured

NetJets N879QS
Hawker 800XP vs. Schleicher ASG-29
Reno, Nevada 2006 -- 3 minor injuries (we were very lucky)

Darryl

Yes terrible accidents such as those cited motivated the regulators
and industry to require the carriage of transponders. The FAA Near
Midair Collision Avoidance database suggests that annual reports of
reported near midair collisions in the US have decreased in number
since the 1980s.

http://www.asias.faa.gov/portal/pls/...pp_module.show...

Still, only 45 of 6624 records (0.6% of the total) in the NMAC
database contain the term "glider". Only nine records contain the
terms "glider" and "US air carrier".

The other 6579 reports (99.4%) do not involve gliders. Many of these
other reported near midair collisions presumably happened between
transponder-equipped powered aircraft.

In conclusion, experience shows that the possibility of a mid-air
collision between a glider and an air carrier is real enough (and
warrants prudent action) but let's put it into perspective. Gliders
form a very small part of the total collision risk that commercial
passengers are exposed to.

Ian Grant IN

There are a lot more GA flights/yr than glider flights/yr. *It would
be interesting to see these statistics stated as a % of all glider
flights and % of all GA flights (I know this is not possible for
gliders as there is no record of the number of flights). I bet the
ratio would be a lot closer, if not reversed...- Hide quoted text -

- Show quoted text -

It's possible that near midair collisions between gliders and air
transport aircraft are under-represented in the NMAC database because
gliders are hard to see, so the airliner crews and ATC may be unaware
of some incidents that the glider pilots know about. For sure.

However, there is no reason to suppose that any aircrew who knows of a
near midair collision with a glider is less likely to report it than a
similar incident with another category of aircraft. Indeed my sense is
that ATC and airliner crews are darn near paranoid about gliders and
have a greater propensity to report such incidents.

This observation knocks on the head the assertion that gliders are
seriously underrepresented in the NMAC statistics, and supports the
conclusion according to these statistics that most near mid-air
collisions involve transponder-equipped powered aircraft. In the
following tragic example near Toronto the radar data from transponder
returns were used to plot the fatal flight paths!
http://www.tsb.gc.ca/eng/rapports-re...6/a06o0206.pdf

Airspace separation is the best bet.

Ian Grant

On Oct 17, 9:43*am, Mark Dickson wrote:
Sorry, but thermalling gliders will almost always show on radar. *


I fly at Lasham (UK) which is relatively close to the ATC Radar
station at Farnborough. It is set to filter out anything moving at low
speeds such as clouds, flocks of birds and gliders thermalling. They
can usually get weak returns from gliders flying straight, but this is
not guaranteed.

Derek C

On 10/17/2010 4:43 AM, Mark Dickson wrote:
Sorry, but thermalling gliders will almost always show on radar.

At 23:39 16 October 2010, John Smith wrote:
Mark Dickson wrote:
No, it's Ryanair. They always look for direct routings, even if it
takes them outside controlled airspace.

They can ask as much as they want, it's the controller authority to
allow it or not. But how can I explain this to somebody who
doesn't even
know that class E airspace is controlled?

Contrary to popular myth, gliders show
as a primary return on radar displays

Contrary to popular myth, stationary primary targets are filtered
out by
the radar software, hence thermalling gliders don't show on the
controller's display.


Even if non-equipped gliders show up, there is no altitude info. In the
US, standard procedure is that IFR traffic is not routed around VFR
airplanes, even if they are transponder equipped. If you are lucky, the
IFR traffic will get a traffic advisory. Keep your fingers crossed that
the IFR traffic has TCAS and that the pilots follow the RA instructions.

--
Mike Schumann

On Oct 17, 5:14*am, Mike Schumann
wrote:
On 10/17/2010 4:43 AM, Mark Dickson wrote:

Sorry, but thermalling gliders will almost always show on radar.

At 23:39 16 October 2010, John Smith wrote:
Mark Dickson wrote:
No, it's Ryanair. *They always look for direct routings, even if it
takes them outside controlled airspace.

They can ask as much as they want, it's the controller authority to
allow it or not. But how can I explain this to somebody who
doesn't even
know that class E airspace is controlled?

Contrary to popular myth, gliders show
as a primary return on radar displays

Contrary to popular myth, stationary primary targets are filtered
out by
the radar software, hence thermalling gliders don't show on the
controller's display.

Even if non-equipped gliders show up, there is no altitude info. *In the
US, standard procedure is that IFR traffic is not routed around VFR
airplanes, even if they are transponder equipped. *If you are lucky, the
IFR traffic will get a traffic advisory. *Keep your fingers crossed that
the IFR traffic has TCAS and that the pilots follow the RA instructions.

--
Mike Schumann

At least in Tucson, I believe that ATC does route IFR traffic away
from transponder-equipped gliders. We have a unique squawk code and,
at least from my observations, controllers keep airliners well away
from gliders so equipped. When my transponder was down for repair, I
got to see a lot of aircraft really close up!

Of course, the unintended consequence is that airliners diverted from
around me are often sent through nearby thermals where some of my non-
transponder equipped colleagues are soaring.

Mike

On Oct 17, 4:32*am, India November wrote:
[snip]
- Show quoted text -

It's possible that near midair collisions between gliders and air
transport aircraft are under-represented in the NMAC database because
gliders are hard to see, so the airliner crews and ATC may be unaware
of some incidents that the glider pilots know about. For sure.

However, there is no reason to suppose that any aircrew who knows of a
near midair collision with a glider is less likely to report it than a
similar incident with another category of aircraft. Indeed my sense is
that ATC and airliner crews are darn near paranoid about gliders and
have a greater propensity to report such incidents.

This observation knocks on the head the assertion that gliders are
seriously underrepresented in the NMAC statistics, and supports the
conclusion according to these statistics that most near mid-air
collisions involve transponder-equipped powered aircraft. In the
following tragic example near Toronto the radar data from transponder
returns were used to plot the fatal flight paths!http://www.tsb.gc.ca/eng/rapports-re.../a06o0206/a06o...

Airspace separation is the best bet.

Ian Grant

Ian

I don't disagree with either of the first two points. And in locations
like near Reno that even if pilots are not hyper-vigilant about close
encounters with gliders that ATC and the rest of the FAA will be if
they are aware of it at all (e.g. from the radio).

However there is just no logical reason for claiming that those two
points extrapolate to somehow "knock[s] on the head the assertion that
gliders are seriously underrepresented in the NMAC statistics". You
have no information about how many near misses might be occurring
between non-transponder equipped gliders not being detected by TCAS
alerts and/or visual identification by airline crews. We just don't
know. Just not knowing is just not knowing.

NMAC and other accident/incident databases are great for some things.
It is educating to just browse through but for making claims either
way with very low indecent numbers and a very large overall expected
under-reporting rate I just do not think that NMAC is en effective
tool in this area.


I also don't understand exactly what you mean by "Airspace separation
is the best bet". I could well agree with you, I just don't know what
you mean. Looking at the USA situation that I understand -- If it
means the full hard separation of all IFR traffic via Class B and
Class C -- then I just do not see that politically ever going to
happen in the USA. Maybe in Europe where it is more like that now (at
least for the airliners, except for cases like we've talked about
here). And do you mean the allowing gliders within that airspace with
transponders (and ADS-B data-out in future?) only or excluding gliders
from that airspace entirely?


Darryl

On Oct 17, 1:43*am, Mark Dickson wrote:
Sorry, but thermalling gliders will almost always show on radar. *

At 23:39 16 October 2010, John Smith wrote:

Mark Dickson wrote:
No, it's Ryanair. *They always look for direct routings, even if it
takes them outside controlled airspace.

They can ask as much as they want, it's the controller authority to
allow it or not. But how can I explain this to somebody who
doesn't even
know that class E airspace is controlled?

Contrary to popular myth, gliders show
as a primary return on radar displays

Contrary to popular myth, stationary primary targets are filtered
out by
the radar software, hence thermalling gliders don't show on the
controller's display.



John is right, and we need to be careful with claims like this because
misunderstanding around statements like this can lead people to
dismiss the role of transponders in providing a valuable tool for
traffic awareness/separation, especially near those airliners and fast
jets.

The answer is both yes (from a technically possible viewpoint) but in
practice it is almost certainly no.

A modern primary radar system will usually have no problem detecting a
glider under benign circumstances, including a fiberglass glider (not
carbon) -- there is enough metal in the glider to show up. However in
practice to have the radar set to detect the glider the controllers
will be seeing all kinds of ground and other clutter (birds, traffic
on roads/freeways, wind turbines, ....). In practice in most places
the Doppler discriminators aka "MTI" (Motion Target Indicator) will be
set to reduce all this clutter and give the radar operator a usable
display. In that practical situation they won't see slow speed gliders
thermalling, those targets would have be removed by the MTI.

It is not possible to say more without knowing the particular
situation. The clutter and other issues, type of radar and target
ranges and elevation etc. If it important you can followup with your
local ATC radar facility and ask them. But I expect the answer in
practice is they will not be able to usefully observe a glider from a
primary radar return.

And even if they could observe the glider the radar likely only
provides location, with no elevation data. e.g. for all civil approach/
terminal radar in the USA. And even if a radar system (like the ARSR-4
used in the USA for civil en-route and CONUS surveillance) does
provide some crude primary radar elevation data it is not always clear
this is passed to particular ATC operators at all, and if it is it is
unlikely to be useful for usual ATC separation services.


Darryl

On 10/17/2010 12:31 PM, Mike the Strike wrote:
On Oct 17, 5:14 am, Mike
wrote:
On 10/17/2010 4:43 AM, Mark Dickson wrote:

Sorry, but thermalling gliders will almost always show on radar.

At 23:39 16 October 2010, John Smith wrote:
Mark Dickson wrote:
No, it's Ryanair. They always look for direct routings, even if it
takes them outside controlled airspace.

They can ask as much as they want, it's the controller authority to
allow it or not. But how can I explain this to somebody who
doesn't even
know that class E airspace is controlled?

Contrary to popular myth, gliders show
as a primary return on radar displays

Contrary to popular myth, stationary primary targets are filtered
out by
the radar software, hence thermalling gliders don't show on the
controller's display.

Even if non-equipped gliders show up, there is no altitude info. In the
US, standard procedure is that IFR traffic is not routed around VFR
airplanes, even if they are transponder equipped. If you are lucky, the
IFR traffic will get a traffic advisory. Keep your fingers crossed that
the IFR traffic has TCAS and that the pilots follow the RA instructions.

--
Mike Schumann

At least in Tucson, I believe that ATC does route IFR traffic away
from transponder-equipped gliders. We have a unique squawk code and,
at least from my observations, controllers keep airliners well away
from gliders so equipped. When my transponder was down for repair, I
got to see a lot of aircraft really close up!

Of course, the unintended consequence is that airliners diverted from
around me are often sent through nearby thermals where some of my non-
transponder equipped colleagues are soaring.

Mike
It's great that your local controllers are doing this. It needs to
happen everywhere. See this study by MIT's Lincoln labs from 2005:

http://www.ll.mit.edu/publications/j...2_04Kuchar.pdf

See pages 287-288. There were an average of 9 TCAS RAs per DAY within
60 miles of the Lincoln Labs sensor in Boston. This is a direct result
of ATC not vectoring traffic around transponder equipped GA aircraft,
and effectively using TCAS as the primary VFR / IFR collision avoidance
system.

--
Mike Schumann

On Oct 17, 12:32*pm, India November wrote:
On Oct 16, 11:47*am, "Matt Herron Jr." wrote:





On Oct 12, 12:00*pm, India November wrote:

On Oct 12, 6:25*pm, Darryl Ramm wrote:

On Oct 12, 2:08*am, John Smith wrote:

Darryl Ramm wrote:

---

Moving topic somewhat but I want to make the point that we've lost
several airliners full of passengers in fatal-midair collisions with
light-aircraft and the response to that was largely transponders and
TCAS/ACAS. And gliders operating near high density airline and fast
jet traffic without transponders are effectively bypassing that
evolution. I worry that human nature and perception of risks can allow
apparent reduction of risks in situation because we don't perceive
those rare but critical accidents happening frequently enough to
register as practical risks even if they have catastrophic outcomes.. I
start my talks on collision avoidance with the following (USA centric
information). There are similar fatal mid-air collisions outside the
USA.

Allegheny 853
MD DC-9 vs. Piper Cherokee
Fairield, Indiana 1969 -- 83 killed

Pacific Southwest 182
Boeing 727 vs. Cessna 172
San Diego, California 1978 -- 144 killed

Aeroméxico 498 (the mid-air that lead to Mode C transponder and TCAS
carriage requirements in the USA)
MD DC-9 vs. Piper Cherokee
Cerritos, California 1986 -- 82 killed, 8 injured

NetJets N879QS
Hawker 800XP vs. Schleicher ASG-29
Reno, Nevada 2006 -- 3 minor injuries (we were very lucky)

Darryl

Yes terrible accidents such as those cited motivated the regulators
and industry to require the carriage of transponders. The FAA Near
Midair Collision Avoidance database suggests that annual reports of
reported near midair collisions in the US have decreased in number
since the 1980s.

http://www.asias.faa.gov/portal/pls/...pp_module.show....

Still, only 45 of 6624 records (0.6% of the total) in the NMAC
database contain the term "glider". Only nine records contain the
terms "glider" and "US air carrier".

The other 6579 reports (99.4%) do not involve gliders. Many of these
other reported near midair collisions presumably happened between
transponder-equipped powered aircraft.

In conclusion, experience shows that the possibility of a mid-air
collision between a glider and an air carrier is real enough (and
warrants prudent action) but let's put it into perspective. Gliders
form a very small part of the total collision risk that commercial
passengers are exposed to.

Ian Grant IN

There are a lot more GA flights/yr than glider flights/yr. *It would
be interesting to see these statistics stated as a % of all glider
flights and % of all GA flights (I know this is not possible for
gliders as there is no record of the number of flights). I bet the
ratio would be a lot closer, if not reversed...- Hide quoted text -

- Show quoted text -

It's possible that near midair collisions between gliders and air
transport aircraft are under-represented in the NMAC database because
gliders are hard to see, so the airliner crews and ATC may be unaware
of some incidents that the glider pilots know about. For sure.

However, there is no reason to suppose that any aircrew who knows of a
near midair collision with a glider is less likely to report it than a
similar incident with another category of aircraft. Indeed my sense is
that ATC and airliner crews are darn near paranoid about gliders and
have a greater propensity to report such incidents.

This observation knocks on the head the assertion that gliders are
seriously underrepresented in the NMAC statistics, and supports the
conclusion according to these statistics that most near mid-air
collisions involve transponder-equipped powered aircraft. In the
following tragic example near Toronto the radar data from transponder
returns were used to plot the fatal flight paths!http://www.tsb.gc.ca/eng/rapports-re.../a06o0206/a06o...

Airspace separation is the best bet.

Ian Grant- Hide quoted text -

- Show quoted text -

That is why I am against fitting transponders to gliders. They are
expensive and do not protect us from 99.9% of the mid-air collisions
(glider/glider or glider/light aircraft) that we are ever likely to
have. The number of glider/Commercial Transport mid-air collisions is
2 to the best of my knowledge, neither of which caused any fatalities
(Reno and Airbus in Class G airspace over France).

Derek C

On Oct 18, 1:38*pm, Derek C wrote:
On Oct 17, 12:32*pm, India November wrote:





On Oct 16, 11:47*am, "Matt Herron Jr." wrote:

On Oct 12, 12:00*pm, India November wrote:

On Oct 12, 6:25*pm, Darryl Ramm wrote:

On Oct 12, 2:08*am, John Smith wrote:

Darryl Ramm wrote:

---

Moving topic somewhat but I want to make the point that we've lost
several airliners full of passengers in fatal-midair collisions with
light-aircraft and the response to that was largely transponders and
TCAS/ACAS. And gliders operating near high density airline and fast
jet traffic without transponders are effectively bypassing that
evolution. I worry that human nature and perception of risks can allow
apparent reduction of risks in situation because we don't perceive
those rare but critical accidents happening frequently enough to
register as practical risks even if they have catastrophic outcomes. I
start my talks on collision avoidance with the following (USA centric
information). There are similar fatal mid-air collisions outside the
USA.

Allegheny 853
MD DC-9 vs. Piper Cherokee
Fairield, Indiana 1969 -- 83 killed

Pacific Southwest 182
Boeing 727 vs. Cessna 172
San Diego, California 1978 -- 144 killed

Aeroméxico 498 (the mid-air that lead to Mode C transponder and TCAS
carriage requirements in the USA)
MD DC-9 vs. Piper Cherokee
Cerritos, California 1986 -- 82 killed, 8 injured

NetJets N879QS
Hawker 800XP vs. Schleicher ASG-29
Reno, Nevada 2006 -- 3 minor injuries (we were very lucky)

Darryl

Yes terrible accidents such as those cited motivated the regulators
and industry to require the carriage of transponders. The FAA Near
Midair Collision Avoidance database suggests that annual reports of
reported near midair collisions in the US have decreased in number
since the 1980s.

http://www.asias.faa.gov/portal/pls/...pp_module.show...

Still, only 45 of 6624 records (0.6% of the total) in the NMAC
database contain the term "glider". Only nine records contain the
terms "glider" and "US air carrier".

The other 6579 reports (99.4%) do not involve gliders. Many of these
other reported near midair collisions presumably happened between
transponder-equipped powered aircraft.

In conclusion, experience shows that the possibility of a mid-air
collision between a glider and an air carrier is real enough (and
warrants prudent action) but let's put it into perspective. Gliders
form a very small part of the total collision risk that commercial
passengers are exposed to.

Ian Grant IN

There are a lot more GA flights/yr than glider flights/yr. *It would
be interesting to see these statistics stated as a % of all glider
flights and % of all GA flights (I know this is not possible for
gliders as there is no record of the number of flights). I bet the
ratio would be a lot closer, if not reversed...- Hide quoted text -

- Show quoted text -

It's possible that near midair collisions between gliders and air
transport aircraft are under-represented in the NMAC database because
gliders are hard to see, so the airliner crews and ATC may be unaware
of some incidents that the glider pilots know about. For sure.

However, there is no reason to suppose that any aircrew who knows of a
near midair collision with a glider is less likely to report it than a
similar incident with another category of aircraft. Indeed my sense is
that ATC and airliner crews are darn near paranoid about gliders and
have a greater propensity to report such incidents.

This observation knocks on the head the assertion that gliders are
seriously underrepresented in the NMAC statistics, and supports the
conclusion according to these statistics that most near mid-air
collisions involve transponder-equipped powered aircraft. In the
following tragic example near Toronto the radar data from transponder
returns were used to plot the fatal flight paths!http://www.tsb.gc.ca/eng/rapports-re.../a06o0206/a06o...

Airspace separation is the best bet.

Ian Grant- Hide quoted text -

- Show quoted text -

That is why I am against fitting transponders to gliders. They are
expensive and do not protect us from 99.9% of the mid-air collisions
(glider/glider or glider/light aircraft) that we are ever likely to
have. The number of glider/Commercial Transport mid-air collisions is
2 to the best of my knowledge, neither of which caused any fatalities
(Reno and Airbus in Class G airspace over France).

Derek C- Hide quoted text -

- Show quoted text -

You should add "miracally". The only reason why we don't have much
more midairs with commercial traffic is that luckily most glider
pilots flying in congested areas have common sense and fly with
transponders. I estimate around 80% of gliders flying XC in the Reno
area use transponders even though it is not mandatory. Otherwise I am
pretty sure we would have a catastrophic midair in this area by now.

Ramy

On Oct 18, 1:38*pm, Derek C wrote:
On Oct 17, 12:32*pm, India November wrote:



On Oct 16, 11:47*am, "Matt Herron Jr." wrote:

On Oct 12, 12:00*pm, India November wrote:

On Oct 12, 6:25*pm, Darryl Ramm wrote:

On Oct 12, 2:08*am, John Smith wrote:

Darryl Ramm wrote:

---

Moving topic somewhat but I want to make the point that we've lost
several airliners full of passengers in fatal-midair collisions with
light-aircraft and the response to that was largely transponders and
TCAS/ACAS. And gliders operating near high density airline and fast
jet traffic without transponders are effectively bypassing that
evolution. I worry that human nature and perception of risks can allow
apparent reduction of risks in situation because we don't perceive
those rare but critical accidents happening frequently enough to
register as practical risks even if they have catastrophic outcomes. I
start my talks on collision avoidance with the following (USA centric
information). There are similar fatal mid-air collisions outside the
USA.

Allegheny 853
MD DC-9 vs. Piper Cherokee
Fairield, Indiana 1969 -- 83 killed

Pacific Southwest 182
Boeing 727 vs. Cessna 172
San Diego, California 1978 -- 144 killed

Aeroméxico 498 (the mid-air that lead to Mode C transponder and TCAS
carriage requirements in the USA)
MD DC-9 vs. Piper Cherokee
Cerritos, California 1986 -- 82 killed, 8 injured

NetJets N879QS
Hawker 800XP vs. Schleicher ASG-29
Reno, Nevada 2006 -- 3 minor injuries (we were very lucky)

Darryl

Yes terrible accidents such as those cited motivated the regulators
and industry to require the carriage of transponders. The FAA Near
Midair Collision Avoidance database suggests that annual reports of
reported near midair collisions in the US have decreased in number
since the 1980s.

http://www.asias.faa.gov/portal/pls/...pp_module.show...

Still, only 45 of 6624 records (0.6% of the total) in the NMAC
database contain the term "glider". Only nine records contain the
terms "glider" and "US air carrier".

The other 6579 reports (99.4%) do not involve gliders. Many of these
other reported near midair collisions presumably happened between
transponder-equipped powered aircraft.

In conclusion, experience shows that the possibility of a mid-air
collision between a glider and an air carrier is real enough (and
warrants prudent action) but let's put it into perspective. Gliders
form a very small part of the total collision risk that commercial
passengers are exposed to.

Ian Grant IN

There are a lot more GA flights/yr than glider flights/yr. *It would
be interesting to see these statistics stated as a % of all glider
flights and % of all GA flights (I know this is not possible for
gliders as there is no record of the number of flights). I bet the
ratio would be a lot closer, if not reversed...- Hide quoted text -

- Show quoted text -

It's possible that near midair collisions between gliders and air
transport aircraft are under-represented in the NMAC database because
gliders are hard to see, so the airliner crews and ATC may be unaware
of some incidents that the glider pilots know about. For sure.

However, there is no reason to suppose that any aircrew who knows of a
near midair collision with a glider is less likely to report it than a
similar incident with another category of aircraft. Indeed my sense is
that ATC and airliner crews are darn near paranoid about gliders and
have a greater propensity to report such incidents.

This observation knocks on the head the assertion that gliders are
seriously underrepresented in the NMAC statistics, and supports the
conclusion according to these statistics that most near mid-air
collisions involve transponder-equipped powered aircraft. In the
following tragic example near Toronto the radar data from transponder
returns were used to plot the fatal flight paths!http://www.tsb.gc.ca/eng/rapports-re.../a06o0206/a06o...

Airspace separation is the best bet.

Ian Grant- Hide quoted text -

- Show quoted text -

That is why I am against fitting transponders to gliders. They are
expensive and do not protect us from 99.9% of the mid-air collisions
(glider/glider or glider/light aircraft) that we are ever likely to
have. The number of glider/Commercial Transport mid-air collisions is
2 to the best of my knowledge, neither of which caused any fatalities
(Reno and Airbus in Class G airspace over France).

Derek C

This statement again suffers from the assumption that there is one
environment that applies to everybody. We have many situations
worldwide where I would hope nobody think a glider needs any mandatory
collision avoidance technology through situations where there is
significant risk of a glider-glider mid-air (e.g. contests, busy
clubs), and in other locations maybe GA traffic offers the most
significant risk. To situations where gliders are in close proximity
to airliners and fast jets and where the product of risk x consequence
should be a serious concern.

The collision at Reno was with a Hawker 800. There have been "close"
incidents with airliners there as well. Large numbers of the glider
pilots who fly near Reno undertsand in detail the traffic patterns,
conclicts and risks and equip wih transponders. We don't need to wait
for a fatality from an airliner collision to prove it is a justified
saftey measure. Risks from other parts of a glider pilots flying
activities need to be considered separately from that risk x
consequence of a collision with an airliner. Whether you might have a
statistically higher probability of having a mid-air with another
glider should not drive the risk decision about whether to utilize a
transponder in these key areas where we have a serious problem with
close proximity of airliner and fast jet traffic.

I hope what is going on here is a reaction to concerns about blanket
transponder mandates. They don't make sense (unless folks in high risk
areas don't volitarilly adopt them or can't be locally forced to if
the voluntary stuff just does not happen).

Darryl