Glider Crash - Minden?

Yuliy Gerchikov wrote:

The truth is, if you can't see this tiny *motionless* speck ...two miles
away ...in the inversion haze ...on one thermalling turn, then it is going
to hit you before you finish the next.

Yuliy,

Interesting test, but I don't think it anyway replicates real life.
Airplanes at a distance, co-altitude on the horizon, are going to be
black dots almost all the time. What you have to train yourself to
look for is a moving black dot against the background. Worse, you have
to also find the black dot that isn't moving - because that is the one
on a perfect collision course. That situation is tought, but not
impossible. If you turn at all, you break the collision course, and
generate motion on the canopy.

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

So I don't buy your analogy - it just doesn't correlate with my
personal experience.

See and avoid is not the best solution, but it does work - if everybody
does it correctly. I'm starting to think that many pilots have never
been trained how to look for traffic - the basic physiological and
environmental facts that have to be understood in order to scan
succesfully for traffic. Scary!

These are great discussions, IMHO - makes us all think about how we fly
and how others fly.

And I know I need to spend less time with MCU and even more time
scanning!

Kirk

Ramy wrote:
Wow, so many aircrafts...
In the 7 years and about 2000 hours I flew my LS4, I never saw
commercial traffic close by, and I fly most of the time in the Reno
area. Maybe it has to do with the fact that I am using a transponder?
I had one close call over airsailing with an airliner in the short time
I flew club gliders without transponders (I believe they all have
transponders now).


Could be where you fly - in the Phoenix area (and most of NW AZ), there
is a lot of traffic. Then again, It doesn't bother me to be around
other airplanes - it's kind of neat to watch a big old airliner cruise
by (and wonder if anyone in it saw me), or get checked out in a thermal
by a couple of AV-8 (which happened to me up by the Grand Canyon - they
altered course and came over to where I was thermalling at about
15,000', went by on either side of the thermal. I waved at them, of
course).

But just cuz you don't see it, don't mean it aint there!

Kirk

Eric,

The pilot who removed his transponder antenna is a friend of mine, and I
talked with him about it at the time.

The glider is an ASW27, he was flying in competition with other pilots in
ASW27s who were well known to him as people and as pilots. Some were
members of his club.

He has a transponder fitted (Becker Mode A/C, not Mode S) because he
frequently flies high in wave, particularly in Scotland, where it is
necessary to talk to an air traffic controller and either a great help or
essential to have a transponder. He is also a professional airline pilot.

During the competition the transponder would not have been turned on. He
started with the antenna fitted because he did not realise the difference in
performance it caused. After two or three days, with his ship not going as
well compared with the others as he expected, he removed it. The
difference was immediate and obvious, he described to me the difference with
it fitted as turning the ASW27 into an ASW20! Remember, he had been flying
with the antenna for some time, it was only in contest against other similar
gliders with good pilots that he saw the difference.

Please do not talk as if flying in UK contests involves the same collision
risk with CAT as flying in the high skies around Minden (I have never done
that, alas!). I understand that there has not been an actual collision in
the UK between a glider and CAT or the military since 1947.

To anyone buying a new modern machine from Schleicher, Schempp or the
others, the cost of fitting a transponder is only a small percentage of the
total cost, but would still involve finding panel space, and sufficient
power (particularly if the transponder is to be on whenever airborne). But
there are still a lot of low value gliders in use in the UK, and a lot of
gliding being done where the actual collision risk where a transponder would
make a difference is very small. In the USA, I wonder how many of the 1-26
fleet are fitted?

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"Eric Greenwell" wrote in message
news:HQ4Kg.227$m36.105@trnddc02...


Derek Copeland wrote:
Jack,

I know that a UK pilot removed a transponder aerial
from his glider part way through a Nationals competition
because he was losing too much performance in relation
to his competitors in similar gliders. Also I fly a
Standard Cirrus, so I need all the performance I can
get!


You can't measure the performance loss that a transponder antenna on your
Std Cirrus, the drag is so little; nonetheless, the fiberglass fuselage
will let you mount one internally. The big advantage is it's protected
from ground and handling damage.

Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

www.motorglider.org - Download "A Guide to Self-launching Sailplane
Operation"

W.J. (Bill) Dean (U.K.). wrote:

After two or three days, with his ship not going as
well compared with the others as he expected, he removed it. The
difference was immediate and obvious, he described to me the difference with
it fitted as turning the ASW27 into an ASW20! Remember, he had been flying
with the antenna for some time, it was only in contest against other similar
gliders with good pilots that he saw the difference.

I remain skeptical: I sure didn't see any difference at all when I
fitted a transponder antenna to my ASH 26 E, flying against gliders I'd
flown with for years, nor have I heard of anyone else noticing a
difference. Perhaps something unusual was occurring in his case.

Please do not talk as if flying in UK contests involves the same collision
risk with CAT as flying in the high skies around Minden (I have never done
that, alas!).

I won't, and I didn't. My remarks were directed at a Std Cirrus pilot
who felt he needed every crumb of performance, and that was why he
wouldn't consider a transponder. My belief the drag increase is
insgnificant, so it shouldn't be a factor in his decision. The need for
it and the cost are the most important factors, I think.


To anyone buying a new modern machine from Schleicher, Schempp or the
others, the cost of fitting a transponder is only a small percentage of the
total cost, but would still involve finding panel space, and sufficient
power (particularly if the transponder is to be on whenever airborne). But
there are still a lot of low value gliders in use in the UK, and a lot of
gliding being done where the actual collision risk where a transponder would
make a difference is very small.

Also the situation in much of the USA. Though, I don't think the value
of the glider should be a factor in the decision to install a
transponder. I realize you are using the glider value as a proxy for the
spare cash the owner has, but I'd rather the focus was on the collision
risk, the value of reducing it, and the cost of installing a transponder.

In the USA, I wonder how many of the 1-26 fleet are fitted?

I don't know, but some do have them in the Minden area.

Are you allowed to fly in airways in the UK (as we do in the US), and
would having a transponder give you greater access to them?

--
Note: email address new as of 9/4/2006
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html

"A Guide to Self-launching Sailplane Operation" at www.motorglider.org

In the UK we are not allowed to fly Gliders in Class
A or Airways, full stop, period! We can sometimes access
Class B and Class D with an ATC clearance by radio.
The vast majority of gliding is done in Glass G airspace
where we are largely segregated from commercial air
traffic. However the latter are increasingly starting
to use the Class G around the smaller regional airports,
which is probably why the CAA wants the compulsory
fitting of Mode S transponders. The other issue is
the use of the open airspace by UAVs (mostly by the
US Military as far as I can find out). There is no
mandatory requirement for fitting airband radios at
the moment, so I don't expect to get any improved access
to controlled airspace by fitting transponders.

In the US the fitting of transponders appears to be
voluntary, if the owners/pilots consider it necessary
in their local airspace. If the CAA gets its way, Mode
S will be compulsory for all aircraft in the UK, including
low value vintage machine that only occasionally fly,
and even when they do stay local to the airfield. Basically
these beautiful machines will probably have to be placed
in museums or scrapped, which in my opinion would be
a great shame. We currently have a thriving vintage
glider movement in the UK.

The UK is a damp little island with far too much cloud,
often with a very low base. To successfully fly cross-country
you really do need all the glide performance you can
get.

Mode S transponders can only give collision warnings
to ACAS/TCAS equipped aircraft, or via radio messages
from radar equipped ATC. They are virtually useless
for preventing collisions between gliders or GA aircraft.
If we have to fit anything, I would prefer to wait
for ADS-B or some development of FLARM, which is of
general use to all pilots. Transponders are crude,
old fashioned, WW2 technology!

Derek Copeland


At 15:24 05 September 2006, Eric Greenwell wrote:
W.J. (Bill) Dean (U.K.). wrote:

After two or three days, with his ship not going as
well compared with the others as he expected, he removed
it. The
difference was immediate and obvious, he described
to me the difference with
it fitted as turning the ASW27 into an ASW20! Remember,
he had been flying
with the antenna for some time, it was only in contest
against other similar
gliders with good pilots that he saw the difference.

I remain skeptical: I sure didn't see any difference
at all when I
fitted a transponder antenna to my ASH 26 E, flying
against gliders I'd
flown with for years, nor have I heard of anyone else
noticing a
difference. Perhaps something unusual was occurring
in his case.

Please do not talk as if flying in UK contests involves
the same collision
risk with CAT as flying in the high skies around Minden
(I have never done
that, alas!).

I won't, and I didn't. My remarks were directed at
a Std Cirrus pilot
who felt he needed every crumb of performance, and
that was why he
wouldn't consider a transponder. My belief the drag
increase is
insgnificant, so it shouldn't be a factor in his decision.
The need for
it and the cost are the most important factors, I think.


To anyone buying a new modern machine from Schleicher,
Schempp or the
others, the cost of fitting a transponder is only
a small percentage of the
total cost, but would still involve finding panel
space, and sufficient
power (particularly if the transponder is to be on
whenever airborne). But
there are still a lot of low value gliders in use
in the UK, and a lot of
gliding being done where the actual collision risk
where a transponder would
make a difference is very small.

Also the situation in much of the USA. Though, I don't
think the value
of the glider should be a factor in the decision to
install a
transponder. I realize you are using the glider value
as a proxy for the
spare cash the owner has, but I'd rather the focus
was on the collision
risk, the value of reducing it, and the cost of installing
a transponder.

In the USA, I wonder how many of the 1-26 fleet are
fitted?

I don't know, but some do have them in the Minden area.

Are you allowed to fly in airways in the UK (as we
do in the US), and
would having a transponder give you greater access
to them?

--
Note: email address new as of 9/4/2006
Change 'netto' to 'net' to email me directly

Eric Greenwell - Washington State, USA

'Transponders in Sailplanes' on the Soaring Safety
Foundation website
www.soaringsafety.org/prevention/articles.html

'A Guide to Self-launching Sailplane Operation' at
www.motorglider.org

wrote:
Derek Copeland wrote:
Whether I would be able to mount the aerial internally
or not would depend on the engineer certifying the
installation. I understand that the latest generation
sailplanes with carbon fibre fuselages will have to
have externally mounted aerials, probably top or bottom
so that they will transmit both up tp TCAS equipped
airliners and down to Air Traffic Control. Although
the aerials are quite short, they do produce a significant
amount of drag. Remember that a 500 kg glider with
a 50:1 glide angle will only have a drag of 10 kg at
best glide speed.

Here is what an aeronautical engineer wrote on our ASH 26 E newsgroup,
responding to the same concern of another owner:

"As a sanity check assume 1/8" by 2" wire (projected area .25 square
inch) with a drag coefficient of 1 (normally a round wire is less) then
the
drag is (.25/144)*1*60*60/295 = 0.02 lbs at 60 knots or 0.08 lbs at 120
kots. (At 60 knots the flat plate drag is about 12 lbs per square
foot).
Even if the antenna was twice as long or twice as thick we are still
looking
at around .04 pounds at 60 knots or 0.16 lbs at 120 knots."

That's very small compared to 10 kg, and it's at 120 knots!


But it is not the drag, but the drag relative to the lift.

NO Antenna
500 kg glider
10 kg drag
L/D = 50.0

Antenna
500.2 kg glider (add antenna weight, liberal guess)
assume shape of antenna is straght wire, no tip (as above)
assume drag is 0.16 lbs = 0.073 kg
assume no interferance drag
L/D = 500.2/10.073 = 49.66

A third of a point loss is significant for those who know how to use it
(I am told).
Fine tune these results with a real antenna and try again.

(Standard Cirrus
330 kg
L/D = 35
9.43 kg drag

L/D w/antenna:
330/(9.43+0.073)=34.73
Noticable if you have done all your gap work, sealing, airfoil tuning,
etc...?)


John Gilbert - Washington State, USA
Std. Cirrus s/n 266


--
Eric Greenwell - Washington State, USA

www.motorglider.org - Download 'A Guide to Self-launching Sailplane
Operation'

"Eric Greenwell" wrote in message
news:XygLg.26301$CL6.23010@trnddc06...


W.J. (Bill) Dean (U.K.) wrote:

After two or three days, with his ship not going as well compared with
the others as he expected, he removed it. The difference was immediate
and obvious, he described to me the difference with it fitted as turning
the ASW27 into an ASW20! Remember, he had been flying with the antenna
for some time, it was only in contest against other similar gliders with
good pilots that he saw the difference.


I remain sceptical: I sure didn't see any difference at all when I fitted
a transponder antenna to my ASH 26 E, flying against gliders I'd flown
with for years, nor have I heard of anyone else noticing a difference.
Perhaps something unusual was occurring in his case.


He was flying in a very competitive Nationals (entry of 35) against 11 other
gliders of identical type. Some 5 of the competitors have represented the
UK in Worlds, including one current world champion. See
http://www.cotswoldgliding.co.uk/com...ts/15m2006.htm . The antenna
was fitted on the port side underneath, close to the wheel door. It was
the type with a short wire and a sphere on the end.



Please do not talk as if flying in UK contests involves the same
collision risk with CAT as flying in the high skies around Minden (I have
never done that, alas!).

I won't, and I didn't. My remarks were directed at a Std Cirrus pilot
who felt he needed every crumb of performance, and that was why he
wouldn't consider a transponder. My belief the drag increase is
insignificant, so it shouldn't be a factor in his decision. The need for
it and the cost are the most important factors, I think.


To anyone buying a new modern machine from Schleicher, Schempp or the
others, the cost of fitting a transponder is only a small percentage of
the total cost, but would still involve finding panel space, and
sufficient power (particularly if the transponder is to be on whenever
airborne). But there are still a lot of low value gliders in use in
the UK, and a lot of gliding being done where the actual collision risk
where a transponder would make a difference is very small.


Also the situation in much of the USA. Though, I don't think the value
of the glider should be a factor in the decision to install a transponder.
I realize you are using the glider value as a proxy for the spare cash the
owner has, but I'd rather the focus was on the collision risk, the value
of reducing it, and the cost of installing a transponder.


It is the cost of the instrument, of the cabling and antenna, of the extra
battery power, and of the installation. It is not only the cost in cash,
but also the cost in space needed, and in loss of disposable weight.

It also has to do with how the glider will be flown. Fitting a transponder
would do hardly anything to reduce collision risk for most gliding in the
UK. It will only help those who can and want to fly high in wave. From
the posts I have been reading the situation is quite different in the Minden
area, though even there it seems that the routeing of CAT into and out of
airfields could be improved.



In the USA, I wonder how many of the 1-26 fleet are fitted?


I don't know, but some do have them in the Minden area.

Are you allowed to fly in airways in the UK (as we do in the US), and
would having a transponder give you greater access to them?


For UK ATS Airspace Classifications see
http://www.caa.co.uk/docs/64/ATS_Classifications.pdf , one page.

For the CAA publication "Guide to Visual Flight Rules in the UK" see
http://www.caa.co.uk/docs/64/DAP_ACD_VFR_Guide.pdf 40 pages.
The section "Gliders" is on page 23.

Note that nowhere is there any mention of transponders. In class A and B
airspace the controller will be helped if a transponder is fitted and used,
which is why some UK pilots are carrying them. Obviously a controller is
more likely to help if the glider can squawk.


Note: email address new as of 9/4/2006
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html

"A Guide to Self-launching Sailplane Operation" at www.motorglider.org


W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.

wrote:
wrote:
Derek Copeland wrote:
Whether I would be able to mount the aerial internally
or not would depend on the engineer certifying the
installation. I understand that the latest generation
sailplanes with carbon fibre fuselages will have to
have externally mounted aerials, probably top or bottom
so that they will transmit both up tp TCAS equipped
airliners and down to Air Traffic Control. Although
the aerials are quite short, they do produce a significant
amount of drag. Remember that a 500 kg glider with
a 50:1 glide angle will only have a drag of 10 kg at
best glide speed.
Here is what an aeronautical engineer wrote on our ASH 26 E newsgroup,
responding to the same concern of another owner:

"As a sanity check assume 1/8" by 2" wire (projected area .25 square
inch) with a drag coefficient of 1 (normally a round wire is less) then
the
drag is (.25/144)*1*60*60/295 = 0.02 lbs at 60 knots or 0.08 lbs at 120
kots. (At 60 knots the flat plate drag is about 12 lbs per square
foot).
Even if the antenna was twice as long or twice as thick we are still
looking
at around .04 pounds at 60 knots or 0.16 lbs at 120 knots."

That's very small compared to 10 kg, and it's at 120 knots!


But it is not the drag, but the drag relative to the lift.

NO Antenna
500 kg glider
10 kg drag
L/D = 50.0

Antenna
500.2 kg glider (add antenna weight, liberal guess)
assume shape of antenna is straght wire, no tip (as above)
assume drag is 0.16 lbs = 0.073 kg
assume no interferance drag
L/D = 500.2/10.073 = 49.66

A third of a point loss is significant for those who know how to use it
(I am told).
Fine tune these results with a real antenna and try again.

(Standard Cirrus
330 kg
L/D = 35
9.43 kg drag

L/D w/antenna:
330/(9.43+0.073)=34.73
Noticable if you have done all your gap work, sealing, airfoil tuning,
etc...?)

The .073kg is at 120 knots, so at 60 knots best L/D, it would be 0.01825
for an L/D of 34.927. At thermalling speeds, where induced drag
dominates, it's insignifcant (one extra bug may cause more loss!), but
perhaps that's a good enough calculation for the UK, where you probably
aren't batting along in a Std Cirrus fast enough to make profile drag
the dominant factor.

--
Note: email address new as of 9/4/2006
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html

"A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Hi,

If I remember my fluid dynamics courses correctly, spheres and round rods
produce a relatively large amount of drag when compared with teardrop or
flared objects. The low cost "stub" antennas are popular transponder
antennas because of their low cost. However, it is my belief that the more
expensive "shark fin" or "blade" antennas will produce much less drag, even
though they are a bit larger. They also look much nicer on a glider. You
can see examples he
http://www.soarmn.com/cumulus/comant.htm

Good Soaring,

Paul Remde
Cumulus Soaring, Inc.
http://www.cumulus-soaring.com

"Eric Greenwell" wrote in message
news:2gpLg.4072$%k5.472@trnddc08...
wrote:
wrote:
Derek Copeland wrote:
Whether I would be able to mount the aerial internally
or not would depend on the engineer certifying the
installation. I understand that the latest generation
sailplanes with carbon fibre fuselages will have to
have externally mounted aerials, probably top or bottom
so that they will transmit both up tp TCAS equipped
airliners and down to Air Traffic Control. Although
the aerials are quite short, they do produce a significant
amount of drag. Remember that a 500 kg glider with
a 50:1 glide angle will only have a drag of 10 kg at
best glide speed.
Here is what an aeronautical engineer wrote on our ASH 26 E newsgroup,
responding to the same concern of another owner:

"As a sanity check assume 1/8" by 2" wire (projected area .25 square
inch) with a drag coefficient of 1 (normally a round wire is less) then
the
drag is (.25/144)*1*60*60/295 = 0.02 lbs at 60 knots or 0.08 lbs at 120
kots. (At 60 knots the flat plate drag is about 12 lbs per square
foot).
Even if the antenna was twice as long or twice as thick we are still
looking
at around .04 pounds at 60 knots or 0.16 lbs at 120 knots."

That's very small compared to 10 kg, and it's at 120 knots!


But it is not the drag, but the drag relative to the lift.

NO Antenna
500 kg glider
10 kg drag
L/D = 50.0

Antenna
500.2 kg glider (add antenna weight, liberal guess)
assume shape of antenna is straght wire, no tip (as above)
assume drag is 0.16 lbs = 0.073 kg
assume no interferance drag
L/D = 500.2/10.073 = 49.66

A third of a point loss is significant for those who know how to use it
(I am told).
Fine tune these results with a real antenna and try again.

(Standard Cirrus
330 kg
L/D = 35
9.43 kg drag

L/D w/antenna:
330/(9.43+0.073)=34.73
Noticable if you have done all your gap work, sealing, airfoil tuning,
etc...?)

The .073kg is at 120 knots, so at 60 knots best L/D, it would be 0.01825
for an L/D of 34.927. At thermalling speeds, where induced drag dominates,
it's insignifcant (one extra bug may cause more loss!), but perhaps that's
a good enough calculation for the UK, where you probably aren't batting
along in a Std Cirrus fast enough to make profile drag the dominant
factor.

--
Note: email address new as of 9/4/2006
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html

"A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Oh really?

Please read
http://www.scottishglidingcentre.co....20MoU%20BGA%20
2005%20lores.pdf
And then re-comment.

Rory

------------------------------------------------------------
Newsgroup: rec.aviation.soaring
Subject: Mode S Transponders....
Author: Derek Copeland
Date/Time: 17:20 05 September 2006
------------------------------------------------------------
In the UK we are not allowed to fly Gliders in Class A or Airways, full
stop, period!