Aug 6th B738 and Glider Near Miss. Frankfurt

On Oct 19, 12:18*am, Darryl Ramm wrote:
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- Hide quoted text -

- Show quoted text -

Yes, but in one area in Europe where transponders are mandatory for
gliders, the ATC controllers often ask the pilots to turn them off on
busy gliding days because of information overload on their screens!
Hence they are a total waste of money and battery power! Now if we
could get a cheap, low power instrument that provides a universal
electronic collision avoidance system, that would be different.

Derek C

On Oct 19, 3:17*am, Derek C wrote:
On Oct 19, 12:18*am, Darryl Ramm wrote:





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/...p_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- Hide quoted text -

- Show quoted text -

Yes, but in one area in Europe where transponders are mandatory for
gliders, the ATC controllers often ask the pilots to turn them off on
busy gliding days because of information overload on their screens!
Hence they are a total waste of money and battery power! *Now if we
could get a cheap, low power instrument that provides a universal
electronic collision avoidance system, that would be different.

Derek C-

P.S. This was a fatal mid-air collision between a glider and a
military light aircraft in the UK that might have been avoided by the
use of such a device:

http://www.aaib.gov.uk/sites/aaib/pu...and_g_ckht.cfm

One of the problems in the UK is large volumes of Class A and D
controlled airspace around major and some minor airports that largely
exclude gliders, except by special local agreements. These cause
bottlenecks in the open Class G airspace used by non-commercial
traffic. This mid-air occured in a fairly narrow gap between the
Heathrow and Brize Norton zones on a very good gliding day. One has to
question why the Grob (power) pilot, who suffered from restricted neck
movement, was carrying out aerobatics in such a congested area!

Derek C

On Oct 18, 7:17*pm, Derek C wrote:
On Oct 19, 12:18*am, Darryl Ramm wrote:



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/...p_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- Hide quoted text -

- Show quoted text -

Yes, but in one area in Europe where transponders are mandatory for
gliders, the ATC controllers often ask the pilots to turn them off on
busy gliding days because of information overload on their screens!
Hence they are a total waste of money and battery power! *Now if we
could get a cheap, low power instrument that provides a universal
electronic collision avoidance system, that would be different.

Derek C

The situation with the Schiphol TMA has come up in this thread earlier
and it should never have happened. There are various filters that
could have been put in place/developed for the screen display data to
avoid that overload. It should have been tested before the deployment.
It should be an embarrassment to the Dutch authorities and a caution
to others but it is not a fundamental problem with transponders or ATC
systems.

The search for low-cost universal device is a dangerous red herring.
That's what has caused so much confusion and mis-set expectations
around ADS-B and UATs in the USA. There are separate threat scenarios
and legacy technologies (transponders, SSR, TCAS, etc.) and new
systems (ADS-B) coming that are *not* replacements for those legacy
systems (and in Europe the ADS-B link layer is Mode S/1090ES) and then
we have innovative technology like Flarm. The challenge is exactly how
all the different parts fits together and what the most important
threats to address for each pilots own situation.

And we can't just ignore legacy technology (like TCAS) for scenarios
where it is important--some of the silliest comments I've seen are
things along the line of dismissing "transponders as old technology"--
they have an important role to fill, especially with that TCAS
compatibility.

The discussion on "universal" collision avoidance technology starts
and ends with there is just no such thing. There are products that
combine different technology (like PowerFLARM) but a full solution
there would still takes multiple products, will not be "low cost" and
such an approach is going to not be justified for most gliders.

BTW that is one reason I worry about blanket national/federal
regulations for any of this stuff and much prefer to see local
voluntary adoption of appropriate technology for these scenarios.
Where that does not happen then consider mandating use but I'd hate to
see that pushed out nationally. e.g. if needed because voluntary
adoption fails I could support putting a transponder TMZ around a busy
mixed airliner/glider location or mandating Flarm in busy contests.
But I'd hate to see national adoption of one technology or anther
mandated especially if it forces people in one location to adopt
something they don't need at all and that costs prevents them
deploying something more useful for their actual need. And yes some
gliders may indeed need more than one technology box (e.g. a
PowerFLARM and Mode S transponder) for their threat scenario.

Darryl

On Oct 19, 4:35*am, Darryl Ramm wrote:
On Oct 18, 7:17*pm, Derek C wrote:


Darryl- Hide quoted text -

- Show quoted text -

Yes, but in one area in Europe where transponders are mandatory for
gliders, the ATC controllers often ask the pilots to turn them off on
busy gliding days because of information overload on their screens!
Hence they are a total waste of money and battery power! *Now if we
could get a cheap, low power instrument that provides a universal
electronic collision avoidance system, that would be different.

Derek C

The situation with the Schiphol TMA has come up in this thread earlier
and it should never have happened. There are various filters that
could have been put in place/developed for the screen display data to
avoid that overload. It should have been tested before the deployment.
It should be an embarrassment to the Dutch authorities and a caution
to others but it is not a fundamental problem with transponders or ATC
systems.

The search for low-cost universal device is a dangerous red herring.
That's what has caused so much confusion and mis-set expectations
around ADS-B and UATs in the USA. There are separate threat scenarios
and legacy technologies (transponders, SSR, TCAS, etc.) and new
systems (ADS-B) coming that are *not* replacements for those legacy
systems (and in Europe the ADS-B link layer is Mode S/1090ES) and then
we have innovative technology like Flarm. The challenge is exactly how
all the different parts fits together and what the most important
threats to address for each pilots own situation.

And we can't just ignore legacy technology (like TCAS) for scenarios
where it is important--some of the silliest comments I've seen are
things along the line of dismissing "transponders as old technology"--
they have an important role to fill, especially with that TCAS
compatibility.

The discussion on "universal" collision avoidance technology starts
and ends with there is just no such thing. There are products that
combine different technology (like PowerFLARM) but a full solution
there would still takes multiple products, will not be "low cost" and
such an approach is going to not be justified for most gliders.

BTW that is one reason I worry about blanket national/federal
regulations for any of this stuff and much prefer to see local
voluntary adoption of appropriate technology for these scenarios.
Where that does not happen then consider mandating use but I'd hate to
see that pushed out nationally. e.g. if needed because voluntary
adoption fails I could support putting a transponder TMZ around a busy
mixed airliner/glider location or mandating Flarm in busy contests.
But I'd hate to see national ...

read more »- Hide quoted text -

- Show quoted text -


If ATC are filtering out the transponder returns from gliders to avoid
screen clutter, then there is no point in gliders carrying these
expensive, power hungry and difficult to service bits of kit!

Generally I am happy with the UK situation where Commercial Air
Traffic flies under IFR in Class A to D airspace and gliders fly VFR
in Class G. This keeps me separated from the airliners. Problem is
that low cost carriers such as Ryanair are increasing flying into
minor regional airfields and creating a demand for more and more
controlled airspace. We are being squeezed into what's left, with a
greater risk of mid-air collisions with GA and military aircraft that
are also largely forced to use the same airspace.

If a low cost/low power collision alert device can be developed, I
would welcome it, especially if it gives me more access to Class D
airspace.

The Americans seem to be forcing Mode S transponders on the whole
World purely because of problems around Reno Nevada!

Derek C

On 10/18/2010 9:25 PM, Derek C wrote:

If a low cost/low power collision alert device can be developed, I
would welcome it, especially if it gives me more access to Class D
airspace.

We all would welcome it, but what do we do until it appears? How many
years do we wait for our dream to come true?

I installed a Mode C transponder in my glider in 2002. At that time,
many pilots decided that transponders were a good idea, but they were
going to wait for the nifty new Mode S transponders with the lower cost
and lower current drain, which were going to be available "real soon
now". Well, seven (7!) years later, that nifty new Mode S transponder
was finally available - the Trig TT21!

I'm afraid this is what is going to happen now, where many pilots decide
that transponders, or Flarm, are a good idea, but they are going to wait
for the nifty new ADS-B transceivers with the lower cost and lower
current drain, which are going to be available "real soon now".

I have no crystal ball, but I expect it will also be many years before
these units are available. In the meantime, these pilots will ignore
usable, affordable devices they could install now (Flarm and
transponders). US pilots will have to wait till April next year for
Flarm, but the transponder everyone wanted in 2002 is available now.
The Americans seem to be forcing Mode S transponders on the whole
World purely because of problems around Reno Nevada!

Nonsense. Mode S is not required in the US for general aviation, only
for airliners. The US does not require transponders of any kind for
gliders and general aviation around Reno. Europe, however, is requiring
Mode S for some aircraft besides airliners. They have the density that
requires Mode S, the US doesn't. They are leading on this issue.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarmhttp://tinyurl.com/yb3xywl
- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what you need to know tinyurl.com/yfs7tnz

On Oct 18, 9:25*pm, Derek C wrote:
On Oct 19, 4:35*am, Darryl Ramm wrote:



On Oct 18, 7:17*pm, Derek C wrote:

Darryl- Hide quoted text -

- Show quoted text -

Yes, but in one area in Europe where transponders are mandatory for
gliders, the ATC controllers often ask the pilots to turn them off on
busy gliding days because of information overload on their screens!
Hence they are a total waste of money and battery power! *Now if we
could get a cheap, low power instrument that provides a universal
electronic collision avoidance system, that would be different.

Derek C

The situation with the Schiphol TMA has come up in this thread earlier
and it should never have happened. There are various filters that
could have been put in place/developed for the screen display data to
avoid that overload. It should have been tested before the deployment.
It should be an embarrassment to the Dutch authorities and a caution
to others but it is not a fundamental problem with transponders or ATC
systems.

The search for low-cost universal device is a dangerous red herring.
That's what has caused so much confusion and mis-set expectations
around ADS-B and UATs in the USA. There are separate threat scenarios
and legacy technologies (transponders, SSR, TCAS, etc.) and new
systems (ADS-B) coming that are *not* replacements for those legacy
systems (and in Europe the ADS-B link layer is Mode S/1090ES) and then
we have innovative technology like Flarm. The challenge is exactly how
all the different parts fits together and what the most important
threats to address for each pilots own situation.

And we can't just ignore legacy technology (like TCAS) for scenarios
where it is important--some of the silliest comments I've seen are
things along the line of dismissing "transponders as old technology"--
they have an important role to fill, especially with that TCAS
compatibility.

The discussion on "universal" collision avoidance technology starts
and ends with there is just no such thing. There are products that
combine different technology (like PowerFLARM) but a full solution
there would still takes multiple products, will not be "low cost" and
such an approach is going to not be justified for most gliders.

BTW that is one reason I worry about blanket national/federal
regulations for any of this stuff and much prefer to see local
voluntary adoption of appropriate technology for these scenarios.
Where that does not happen then consider mandating use but I'd hate to
see that pushed out nationally. e.g. if needed because voluntary
adoption fails I could support putting a transponder TMZ around a busy
mixed airliner/glider location or mandating Flarm in busy contests.
But I'd hate to see national ...

read more »- Hide quoted text -

- Show quoted text -

If ATC are filtering out the transponder returns from gliders to avoid
screen clutter, then there is no point in gliders carrying these
expensive, power hungry and difficult to service bits of kit!

No they filter by altitude band, by assigned controller, etc. And as
I've pointed out in this thread before the TCAS in the airliners keep
working regardless of what the controller sees.


Generally I am happy with the UK situation where Commercial Air
Traffic flies under IFR in Class A to D airspace and gliders fly VFR
in Class G. This keeps me separated from the airliners. Problem is
that low cost carriers such as Ryanair are increasing flying into
minor regional airfields and creating a demand for more and more
controlled airspace. We are being squeezed into what's left, with a
greater risk of mid-air collisions with GA and military aircraft that
are also largely forced to use the same airspace.

If a low cost/low power collision alert device can be developed, I
would welcome it, especially if it gives me more access to Class D
airspace.

Yes and that device will look and smell like a transponder. If not
what kind of device do you think it will be that can interoperate with
SSR radar and TCAS etc. or be a link in future for 1090ES? I don't see
anybody making something significantly cheaper than a Trig TT21 or
similar Transponder? I don't know how Trig and others keep the costs
down on such small volumes as they are.

The Americans seem to be forcing Mode S transponders on the whole
World purely because of problems around Reno Nevada!

The Americans are doing nothing to you. Ryanair maybe.

Derek C

On Oct 19, 6:49*am, Darryl Ramm wrote:
On Oct 18, 9:25*pm, Derek C wrote:





On Oct 19, 4:35*am, Darryl Ramm wrote:

On Oct 18, 7:17*pm, Derek C wrote:

Darryl- Hide quoted text -

- Show quoted text -

Yes, but in one area in Europe where transponders are mandatory for
gliders, the ATC controllers often ask the pilots to turn them off on
busy gliding days because of information overload on their screens!
Hence they are a total waste of money and battery power! *Now if we
could get a cheap, low power instrument that provides a universal
electronic collision avoidance system, that would be different.

Derek C

The situation with the Schiphol TMA has come up in this thread earlier
and it should never have happened. There are various filters that
could have been put in place/developed for the screen display data to
avoid that overload. It should have been tested before the deployment..
It should be an embarrassment to the Dutch authorities and a caution
to others but it is not a fundamental problem with transponders or ATC
systems.

The search for low-cost universal device is a dangerous red herring.
That's what has caused so much confusion and mis-set expectations
around ADS-B and UATs in the USA. There are separate threat scenarios
and legacy technologies (transponders, SSR, TCAS, etc.) and new
systems (ADS-B) coming that are *not* replacements for those legacy
systems (and in Europe the ADS-B link layer is Mode S/1090ES) and then
we have innovative technology like Flarm. The challenge is exactly how
all the different parts fits together and what the most important
threats to address for each pilots own situation.

And we can't just ignore legacy technology (like TCAS) for scenarios
where it is important--some of the silliest comments I've seen are
things along the line of dismissing "transponders as old technology"--
they have an important role to fill, especially with that TCAS
compatibility.

The discussion on "universal" collision avoidance technology starts
and ends with there is just no such thing. There are products that
combine different technology (like PowerFLARM) but a full solution
there would still takes multiple products, will not be "low cost" and
such an approach is going to not be justified for most gliders.

BTW that is one reason I worry about blanket national/federal
regulations for any of this stuff and much prefer to see local
voluntary adoption of appropriate technology for these scenarios.
Where that does not happen then consider mandating use but I'd hate to
see that pushed out nationally. e.g. if needed because voluntary
adoption fails I could support putting a transponder TMZ around a busy
mixed airliner/glider location or mandating Flarm in busy contests.
But I'd hate to see national ...

read more »- Hide quoted text -

- Show quoted text -

If ATC are filtering out the transponder returns from gliders to avoid
screen clutter, then there is no point in gliders carrying these
expensive, power hungry and difficult to service bits of kit!

No they filter by altitude band, by assigned controller, etc. And as
I've pointed out in this thread before the TCAS in the airliners keep
working regardless of what the controller sees.



Generally I am happy with the UK situation where Commercial Air
Traffic flies under IFR in Class A to D airspace and gliders fly VFR
in Class G. This keeps me separated from the airliners. Problem is
that low cost carriers such as Ryanair are increasing flying into
minor regional airfields and creating a demand for more and more
controlled airspace. We are being squeezed into what's left, with a
greater risk of mid-air collisions with GA and military aircraft that
are also largely forced to use the same airspace.

If a low cost/low power collision alert device can be developed, I
would welcome it, especially if it gives me more access to Class D
airspace.

Yes and that device will look and smell like a transponder. If not
what kind of device do you think it will be that can interoperate with
SSR radar and TCAS etc. or be a link in future for 1090ES? I don't see
anybody making something significantly cheaper than a Trig TT21 or
similar Transponder? I don't know how Trig and others keep the costs
down on such small volumes as they are.

The Americans seem to be forcing Mode S transponders on the whole
World purely because of problems around Reno Nevada!

The Americans are doing nothing to you. Ryanair maybe.



The original poster in this thread sort of suggested that because of
an alleged near miss between a Ryanair jet and a glider near
Frankfurt, all gliders should carry transponders and that is
irresponsible not to do so. While I would not like to be responsible
for bringing down a passenger jet, there are other procedural and
technical ways of addressing this almost infinitesimally small risk.
The vast majority of glider mid-air collisions are with other gliders
and light GA aircraft, which transponders don't help with.

Derek C

Mike - It is common procedure for controllers in the Reno area to route
heavies away from transponder equipped gliders. I find it difficult to
comprehend why you are so antagonistic towards what many others and I
feel is common sense.

MG

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.

On 10/20/2010 12:20 AM, Mike I Green wrote:
Mike - It is common procedure for controllers in the Reno area to route
heavies away from transponder equipped gliders. I find it difficult to
comprehend why you are so antagonistic towards what many others and I
feel is common sense.

MG

I think that you misinterpret my attitude. My view is that see and
avoid is obsolete in today's airspace environment and that the FARs need
to be changed so that ALL ATC controllers are responsible to provide
separation services between VFR and IFR aircraft.

As things stand today in the US, technically, ATC only provides
separation services between IFR aircraft outside of Class A and B
airspace. It is up to the IFR pilots to see and avoid VFR aircraft at
all times. If the IFR pilots get a verbal traffic advisory that's a
marginally helpful plus. If they get rerouted, that's ideal.

We need to work on getting the local procedures that you have negotiated
with your controllers in RENO implemented nation wide.

Mike Schumann


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.

On Thu, 14 Oct 2010 13:43:34 -0500, Mike Schumann
wrote:

For FLARM to be effective, everyone has to install.

From my point of view, this is totally false.

I require my Flarm unit to help me spot gliders I may have not seen
yet. If one of those is flarm-equipped, it will (wiht a high
probability, not certainly) warn me of it's existence and position.
And it does this very, very well.
It will also trigger an alarm if the projected cone of possible
trajectories may interfere with my own path.

If other gliders are not equipped, it won't bother the functions of my
Flarm, nor I will suffer for this. I will keep on relying on my vision
for separation, like I always do. Maybe I will spot them later, maybe
I won't see them at all.

They just don't know what they're missing. Or.. what gliders they're
not spotting.

But, there's no such thing as a "Flarm system". There are Flarms, and
Flarms work.

Aldo Cernezzi