Glider Crash - Minden?

Ramy, I would agree. Mode A isn't completely worthless, since at least the
airliner knows you are around. Clearly Mode C provides more "protection".

Glen
"Ramy" wrote in message
oups.com...
Thanks Glen. I am not aware of any transponder equiped glider not using
mode C. Seems like once you go through the hassle and cost of
installing a transponder, the encoder is the easy part. Mode A sounds
almost useless, more confusing then not. A mode A transponder could
signal an alert to any airline crusing at 30K above.
Which baffles me - Why aren't modern transponders already including
internal encoder??

Ramy

Glen Kelley wrote:
Ramy,

The problem is that TCAS will display you as a target with altitude
unknown
(unless you have mode c with an encoding altimeter). Therefore, TCAS
will
only call you out as traffic and display your position without generating
a
Resolution Advisory (RA). We see this pretty often as VFR traffic. We
will
be looking hard for the traffic, but won't necessarily maneuver the
aircraft, since we can't see altitude/heading.

If in fact, the sailplane does have mode C with an encoding altimeter,
then
the RA will be generated and you should see the big bird maneuver to
avoid
the conflict. Note that a TCAS RA will direct maneuvering in the
vertical
only, since TCAS azimuth is considered too innacurate to generate
turn-based
avoidance. Typical RAs would be "Climb,Climb, Climb - Descend, Descend,
Descend - Reduce Climb - Reduce Descent, etc".

I guess I figured most of the gliders with transponders weren't using
Mode
C, so good catch.

Glen
"Ramy" wrote in message
ups.com...
Thanks for the excellent overview, Glen. Regarding number 3, why would
a TCAS equipped airliner pilot need to see me if the TCAS gives the
resolution? I'm pretty sure most of the airliners vectored around me
never actually see me (although I always
wave ;-)

Ramy

Glen Kelley wrote:
A few additions to Kirk's excellent points - from the background of
former
fighter pilot, current airline pilot, and current glider pilot:

1. We often surprise each other in sailplanes with how hard it is to
see
each other. Don't expect an airline pilot to be any better at it!
The
fighter pilot at least will have good visual acuity and is used to
looking
for small targets.

2. Airline pilots don't carry sectionals - at the speeds we operate,
there
would be little time to use them anyway. Fighter pilots will carry a
low
level map and will have thought about visual traffic conflicts, wires,
terrain, etc in the planning stages. At the speeds they operate, they
aren't looking at those maps very often, once airborne.

3. The busier glider operations are notam'd and often referred to by
atc
controllers. If you have an operable transponder, you will *normally*
be
called out by atc and if TCAS equipped, airline pilots will be aware
of
your
location. They would still have to see you to maneuver away from you.
(See
note 1.) Big airliners are not very maneuverable (mine - the Boeing
737 -
is limited to 2.5 g!).

4. Fighters are a different case. They don't have TCAS and only some
of
them have the ability to interrogate/detect transponder targets. Some
of
them have air intercept radar capability, but sailplanes are small
radar
targets and will often (usually!) be filtered out because of their low
speeds and altitudes - like highway traffic. If they are at low
altitude,
fighters usually operate at high speed (420 - 540 indicated, except
the
A-10). As Kirk pointed out they will almost never be alone, but will
be
in
formations of 2 - 4. When low level (100 to 1500 agl, most commonly
300 -
500agl), they will normally *not* be receiving traffic information
from
ATC.
When operating in a MOA, there may be intercept controllers who can
call
out
glider traffic, but again, without a transponder, it is unlikely. The
formations will vary, but most pairs of flight lead and wingman will
be
laterally spread by 5000 to 10000 feet, for visual lookout. The
flight
lead
will be spending quite a bit of his time looking forward for threat
detection and navigation, but the wingman will be spending less time
looking
forward because he must maintain formation. If they see you, they
have
an
excellent capability to avoid you. Head on and tail on, the sailplane
has
the tiny visual profile that fighter designers dream of.... In other
words,
you are nearly invisible unless you have a wing up in a turn/thermal.

5. As Kirk said, the primary threat is at 6 o'clock, because it is
the
hardest to see - essentially, only the overtaking aircraft has a
reasonable
chance of avoiding a collision. Therefore, if you know you are
operating
in
a high threat area: MOA, low level route, approach corridor, VFR
flyway,
near an airport etc, I would "belly check" periodically, depending on
the
nature of the threat. The timing is based on the amount of time it
takes
for
the threat aircraft to close from outside visual range to hitting me
from
the 6 o'clock position. I use visual ranges of 8nm for airliners, 5
nm
for
small commercial jets (corporate and regional jets) and fighters, and
3
nm
for light aircraft - adjust as your visual acuity and experience
dictate.
I
use worst-case speeds as follows: airliner and small jets - 4 nm/min,
fighters - 8 nm/min, and light aircraft - 2.5 nm/min. Combing
detection
ranges and times, I calculate: airliners - 2 min, small jets - 1 min
and
15
sec, fighters - roughly 40 sec, and light planes - approx 1 min and 15
sec.
So... if you are straight and level for more than these times, there
is
sufficient time for an aircraft to move from outside (my) visual range
to
the same airspace as my (your) little pink body. As you would probably
guess, fighters are the worst case because of their relatively small
size
and high closure rate. On the positive side, there are typically more
eyeballs with better acuity and better maneuverability involved.
Interestingly, small jets and light aircraft are not that far behind,
as
far
as detection time is concerned. In my experience they are far less
likely
to see you than the fighters. The same is true for airliners, but
because
of their size you have more time to see them coming...

6. How to do a belly check: No, I don't hack a stopwatch, but I keep
the
above times in mind with respect to the likely threat for my area. My
primary threat is small jet/light aircraft that operate on various
highway/flyways and approach corridors. Away from these specific
areas,
traffic density is extremely low. First clear your "new six" - if you
are
going to turn left, look to the area behind to the right 4 - 5 oclock
position - this will be your new blind spot. Next clear your new nose
position - this is where you are going to roll out. Finally make a 45
deg
turn to the left and visually clear your "old six", which is now at
your
left 7 to 8 o'clock. Often/usually, a belly check can be incorporated
into
turns you are going to make anyway, for other reasons. When you
visually
clear, make sure you focus on something on the horizon, otherwise you
are
only visually clearing out to an arms length. If I really need to
hold a
straight line, I do the belly check as a gentle 45 deg turn to each
side.

7. In a thermal, periodically check to the outside of your term to
clear
your "new six". If there are other sailplanes with you in the
thermal,
of
course they are the primary threats for midair, but you still need to
check
for other aircraft. Fortunately, you are easier to see while turning -
as
long as the other pilots are looking...

8. Proximity to clouds. You need to think about what you are doing
when
you are near cloudbase, in proximity to likely IFR traffic. If you
are
500'
below cloudbase (perfectly legal), and an airliner descends out of the
cloud
at 250kt on his descent profile on collision course (perfectly legal),
there
may be as little as 20 seconds to impact. If you are tail on when
this
happens - good luck. I'm sure no one would ever be right at cloudbase
on
a
nice day, because that would violate the FARs - more importantly, you
are
"rolling the bones" every time you do this on a known approach
corridor.

9. Conclusion. If you fly in a high airliner/small jet threat area
and
can afford a transponder it will help other people see/avoid you. If
your
primary threat comes from military operations in MOAs, I would not
spend
the
money on a transponder unless I knew those fighters have intercept/atc
controllers passing them information. The various TPAS - type devices
will
help your see/avoid efforts and should help in the case of fighters,
although the flight lead is likely the only one squawking in the
formation.
Only you/your club knows the primary threats for your particular
operating
area and you need to understand what they are. Taylor your altitude
awareness/cloud avoidance and belly check frequency to the nature of
your
local area. Don't cede visual lookout/avoidance responsibility to
someone
else - ever. Sailplane right-of-way is a myth in most situations and
a
comfort only to your survivors/legal counsel.

Hope this helps.

Glen

Jack, I can't agree that this is negligence on the jet pilot's part - at
least not until the investigation is complete.

Sailplanes are very hard to see. We surprise each other from time to time
at much slower closure rates than any jet is going to see closing with a
sailplane. Failure to maintain visual separation is a given, but negligence
is a stretch until someone shows the Captain/FO of the corporate jet were
reading the newspaper, serving drinks to the pax, or something equally
unlikely in the descent phase.

As far as airliner speeds and routing go, who do you think is going to win
if the airline industry is going to have to slow down or otherwise adjust to
blend with sailplane traffic (read that burn more gas and arrive later)? My
bet is with the airlines and flying public. Think about all the airports
that are closed after new housing encroaches on the airport boundaries. As
a small interest group we need to pick our battles.

I have never flown at Minden, but it sounds like the local crowd clearly
understands what is at stake and have tried to be good neighbors. Since no
one was seriously hurt, perhaps the flying environment won't change much.

Glen



"Jack" wrote in message
ps.com...
I just spent the time to read this whole thread,. Only my friend and
former hangar mate, the Mosquito pilot from Houston, makes real sence.
If you cannot see and avoid in visual flight rules area... SLOW DOWN.
Failure to do so is irresponsible. We don't need transponders if we all
avoid each other and that requires time to see and react. To me this is
the equivalent of riding with my brother in Phoenix who likes to drive
90 on the freeway, tailgating impossibly close, and passing on both
shoulders. It's crazy. I only go with him if I'm driving these days.
What I fear is the jet pilot's neglegence will be paid for by lost
flying priviledges in the soaring community. The other piece is going
into an area of reputed heavy glider traffic. Shouldn't she have known
that? Perhaps slowing them down isn't realistic. Demanding that at
least one of them have his/her head out of the cockpit isn't, in my
opinion.

Jack Womack
PIK-20B N77MA (TE)

Like Jack, I just read the whole thread. 4 comments:

1. Remember, the most important glass in a glass cockpit
is above the instrument panel. I used to quote this
to airline pilots, but these days I find it appropos
for many gadget-oriented glider drivers.

2. If you're not seeing much traffic, you're just not
looking hard enough.

3. I tried the 10 point font 'o' at ten feet. Even
in light blue it was clearly visible. At age 46, it's
actually harder to see it at 10 inches! I see another
aircraft at 10 miles, I wish I could read my altimeter
to tell ATC where I am ;o)

4. The rules are see and avoid, and give way to the
glider. The PIC is responsible for knowing all pertinent
information about the intended flight. Adjusting speed
or flight path to avoid heavy glider traffic is not
just a good idea, it's the law.



At 04:42 01 September 2006, Glen Kelley wrote:
Ramy, I would agree. Mode A isn't completely worthless,
since at least the
airliner knows you are around. Clearly Mode C provides
more 'protection'.

Glen
'Ramy' wrote in message
roups.com...
Thanks Glen. I am not aware of any transponder equiped
glider not using
mode C. Seems like once you go through the hassle
and cost of
installing a transponder, the encoder is the easy
part. Mode A sounds
almost useless, more confusing then not. A mode A
transponder could
signal an alert to any airline crusing at 30K above.
Which baffles me - Why aren't modern transponders
already including
internal encoder??

Ramy

Glen Kelley wrote:
Ramy,

The problem is that TCAS will display you as a target
with altitude
unknown
(unless you have mode c with an encoding altimeter).
Therefore, TCAS
will
only call you out as traffic and display your position
without generating
a
Resolution Advisory (RA). We see this pretty often
as VFR traffic. We
will
be looking hard for the traffic, but won't necessarily
maneuver the
aircraft, since we can't see altitude/heading.

If in fact, the sailplane does have mode C with an
encoding altimeter,
then
the RA will be generated and you should see the big
bird maneuver to
avoid
the conflict. Note that a TCAS RA will direct maneuvering
in the
vertical
only, since TCAS azimuth is considered too innacurate
to generate
turn-based
avoidance. Typical RAs would be 'Climb,Climb, Climb
- Descend, Descend,
Descend - Reduce Climb - Reduce Descent, etc'.

I guess I figured most of the gliders with transponders
weren't using
Mode
C, so good catch.

Glen
'Ramy' wrote in message
ups.com...
Thanks for the excellent overview, Glen. Regarding
number 3, why would
a TCAS equipped airliner pilot need to see me if
the TCAS gives the
resolution? I'm pretty sure most of the airliners
vectored around me
never actually see me (although I always
wave ;-)

Ramy

Glen Kelley wrote:
A few additions to Kirk's excellent points - from
the background of
former
fighter pilot, current airline pilot, and current
glider pilot:

1. We often surprise each other in sailplanes with
how hard it is to
see
each other. Don't expect an airline pilot to be
any better at it!
The
fighter pilot at least will have good visual acuity
and is used to
looking
for small targets.

2. Airline pilots don't carry sectionals - at the
speeds we operate,
there
would be little time to use them anyway. Fighter
pilots will carry a
low
level map and will have thought about visual traffic
conflicts, wires,
terrain, etc in the planning stages. At the speeds
they operate, they
aren't looking at those maps very often, once airborne.

3. The busier glider operations are notam'd and often
referred to by
atc
controllers. If you have an operable transponder,
you will *normally*
be
called out by atc and if TCAS equipped, airline pilots
will be aware
of
your
location. They would still have to see you to maneuver
away from you.
(See
note 1.) Big airliners are not very maneuverable
(mine - the Boeing
737 -
is limited to 2.5 g!).

4. Fighters are a different case. They don't have
TCAS and only some
of
them have the ability to interrogate/detect transponder
targets. Some
of
them have air intercept radar capability, but sailplanes
are small
radar
targets and will often (usually!) be filtered out
because of their low
speeds and altitudes - like highway traffic. If
they are at low
altitude,
fighters usually operate at high speed (420 - 540
indicated, except
the
A-10). As Kirk pointed out they will almost never
be alone, but will
be
in
formations of 2 - 4. When low level (100 to 1500
agl, most commonly
300 -
500agl), they will normally *not* be receiving traffic
information
from
ATC.
When operating in a MOA, there may be intercept controllers
who can
call
out
glider traffic, but again, without a transponder,
it is unlikely. The
formations will vary, but most pairs of flight lead
and wingman will
be
laterally spread by 5000 to 10000 feet, for visual
lookout. The
flight
lead
will be spending quite a bit of his time looking
forward for threat
detection and navigation, but the wingman will be
spending less time
looking
forward because he must maintain formation. If they
see you, they
have
an
excellent capability to avoid you. Head on and tail
on, the sailplane
has
the tiny visual profile that fighter designers dream
of.... In other
words,
you are nearly invisible unless you have a wing up
in a turn/thermal.

5. As Kirk said, the primary threat is at 6 o'clock,
because it is
the
hardest to see - essentially, only the overtaking
aircraft has a
reasonable
chance of avoiding a collision. Therefore, if you
know you are
operating
in
a high threat area: MOA, low level route, approach
corridor, VFR
flyway,
near an airport etc, I would 'belly check' periodically,
depending on
the
nature of the threat. The timing is based on the
amount of time it
takes
for
the threat aircraft to close from outside visual
range to hitting me
from
the 6 o'clock position. I use visual ranges of 8nm
for airliners, 5
nm
for
small commercial jets (corporate and regional jets)
and fighters, and
3
nm
for light aircraft - adjust as your visual acuity
and experience
dictate.
I
use worst-case speeds as follows: airliner and small
jets - 4 nm/min,
fighters - 8 nm/min, and light aircraft - 2.5 nm/min.
Combing
detection
ranges and times, I calculate: airliners - 2 min,
small jets - 1 min
and
15
sec, fighters - roughly 40 sec, and light planes
- approx 1 min and 15
sec.
So... if you are straight and level for more than
these times, there
is
sufficient time for an aircraft to move from outside
(my) visual range
to
the same airspace as my (your) little pink body.
As you would probably
guess, fighters are the worst case because of their
relatively small
size
and high closure rate. On the positive side, there
are typically more
eyeballs with better acuity and better maneuverability
involved.
Interestingly, small jets and light aircraft are
not that far behind,
as
far
as detection time is concerned. In my experience
they are far less
likely
to see you than the fighters. The same is true for
airliners, but
because
of their size you have more time to see them coming...

6. How to do a belly check: No, I don't hack a
stopwatch, but I keep
the
above times in mind with respect to the likely threat
for my area. My
primary threat is small jet/light aircraft that operate
on various
highway/flyways and approach corridors. Away from
these specific
areas,
traffic density is extremely low. First clear your
'new six' - if you
are
going to turn left, look to the area behind to the
right 4 - 5 oclock
position - this will be your new blind spot. Next
clear your new nose
position - this is where you are going to roll out.
Finally make a 45
deg
turn to the left and visually clear your 'old six',
which is now at
your
left 7 to 8 o'clock. Often/usually, a belly check
can be incorporated
into
turns you are going to make anyway, for other reasons.
When you
visually
clear, make sure you focus on something on the horizon,
otherwise you
are
only visually clearing out to an arms length. If
I really need to
hold a
straight line, I do the belly check as a gentle 45
deg turn to each
side.

7. In a thermal, periodically check to the outside
of your term to
clear
your 'new six'. If there are other sailplanes with
you in the
thermal,
of
course they are the primary threats for midair, but
you still need to
check
for other aircraft. Fortunately, you are easier to
see while turning -
as
long as the other pilots are looking...

8. Proximity to clouds. You need to think about
what you are doing
when
you are near cloudbase, in proximity to likely IFR
traffic. If you
are
500'
below cloudbase (perfectly legal), and an airliner
descends out of the
cloud
at 250kt on his descent profile on collision course
(perfectly legal),
there
may be as little as 20 seconds to impact. If you
are tail on when
this
happens - good luck. I'm sure no one would ever
be right at cloudbase
on
a
nice day, because that would violate the FARs -
more importantly, you
are
'rolling the bones' every time you do this on a known
approach
corridor.

9. Conclusion. If you fly in a high airliner/small
jet threat area
and
can afford a transponder it will help other people
see/avoid you. If
your
primary threat comes from military operations in
MOAs, I would not
spend
the
money on a transponder unless I knew those fighters
have intercept/atc
controllers passing them information. The various
TPAS - type devices
will
help your see/avoid efforts and should help in the
case of fighters,
although the flight lead is likely the only one squawking
in the
formation.
Only you/your club knows the primary threats for
your particular
operating
area and you need to understand what they are. Taylor
your altitude
awareness/cloud avoidance and belly check frequency
to the nature of
your
local area. Don't cede visual lookout/avoidance
responsibility to
someone
else - ever. Sailplane right-of-way is a myth in
most situations and
a
comfort only to your survivors/legal counsel.

Hope this helps.

Glen

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.

No. YOU are going to hit it.

Ok, I'll accept "we'll hit each other" but I can't let the arrogance of
"it is going to hit you" pass without comment.

Powered aircraft are only one user of airspace.

GC

Graeme Cant wrote:
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.

No. YOU are going to hit it.

Ok, I'll accept "we'll hit each other" but I can't let the arrogance of
"it is going to hit you" pass without comment.

Powered aircraft are only one user of airspace.

My apologies, Yuliy. I misread your post as coming from a power pilot
with the "How can I possibly be expected to get out of a glider's road?"
point of view. when I re-read your post I'm 180 degrees wrong! Sorry!

GC

GC

All the transponders currently listed by Filser
http://www.filser.de/onlineshop/english/ are modes A/C and S, and have
extended squitter; they all have an integral alticoder. These are probably
the cheapest on the UK market http://www.lxavionics.co.uk/ .

I would be surprised if this is not true of other makes, I am sure it soon
will be.

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


"Ramy" wrote in message
oups.com...

Thanks Glen. I am not aware of any transponder equiped glider not using
mode C. Seems like once you go through the hassle and cost of
installing a transponder, the encoder is the easy part. Mode A sounds
almost useless, more confusing then not. A mode A transponder could
signal an alert to any airline crusing at 30K above.
Which baffles me - Why aren't modern transponders already including
internal encoder??

Ramy

Ramy, With regard to the "signal an alert to any airline cruising at
30K above", most TCAS equipment will only show targets 10k above or
below their own ship, and that is selectable. On our TCAS the
selections are "above, auto, below'.
I will typically in cruise, select the below feature, especially if
negotiating weather, to see which way the other guys are going. Plus in
the descent it's nice for planning purposes, you can see where the
traffic your descending into is.


Ramy wrote:
Thanks Glen. I am not aware of any transponder equiped glider not using
mode C. Seems like once you go through the hassle and cost of
installing a transponder, the encoder is the easy part. Mode A sounds
almost useless, more confusing then not. A mode A transponder could
signal an alert to any airline crusing at 30K above.
Which baffles me - Why aren't modern transponders already including
internal encoder??

Ramy

Glen Kelley wrote:
Ramy,

The problem is that TCAS will display you as a target with altitude unknown
(unless you have mode c with an encoding altimeter). Therefore, TCAS will
only call you out as traffic and display your position without generating a
Resolution Advisory (RA). We see this pretty often as VFR traffic. We will
be looking hard for the traffic, but won't necessarily maneuver the
aircraft, since we can't see altitude/heading.

If in fact, the sailplane does have mode C with an encoding altimeter, then
the RA will be generated and you should see the big bird maneuver to avoid
the conflict. Note that a TCAS RA will direct maneuvering in the vertical
only, since TCAS azimuth is considered too innacurate to generate turn-based
avoidance. Typical RAs would be "Climb,Climb, Climb - Descend, Descend,
Descend - Reduce Climb - Reduce Descent, etc".

I guess I figured most of the gliders with transponders weren't using Mode
C, so good catch.

Glen
"Ramy" wrote in message
ups.com...
Thanks for the excellent overview, Glen. Regarding number 3, why would
a TCAS equipped airliner pilot need to see me if the TCAS gives the
resolution? I'm pretty sure most of the airliners vectored around me
never actually see me (although I always
wave ;-)

Ramy

Glen Kelley wrote:
A few additions to Kirk's excellent points - from the background of
former
fighter pilot, current airline pilot, and current glider pilot:

1. We often surprise each other in sailplanes with how hard it is to see
each other. Don't expect an airline pilot to be any better at it! The
fighter pilot at least will have good visual acuity and is used to
looking
for small targets.

2. Airline pilots don't carry sectionals - at the speeds we operate,
there
would be little time to use them anyway. Fighter pilots will carry a low
level map and will have thought about visual traffic conflicts, wires,
terrain, etc in the planning stages. At the speeds they operate, they
aren't looking at those maps very often, once airborne.

3. The busier glider operations are notam'd and often referred to by atc
controllers. If you have an operable transponder, you will *normally* be
called out by atc and if TCAS equipped, airline pilots will be aware of
your
location. They would still have to see you to maneuver away from you.
(See
note 1.) Big airliners are not very maneuverable (mine - the Boeing
737 -
is limited to 2.5 g!).

4. Fighters are a different case. They don't have TCAS and only some of
them have the ability to interrogate/detect transponder targets. Some of
them have air intercept radar capability, but sailplanes are small radar
targets and will often (usually!) be filtered out because of their low
speeds and altitudes - like highway traffic. If they are at low
altitude,
fighters usually operate at high speed (420 - 540 indicated, except the
A-10). As Kirk pointed out they will almost never be alone, but will be
in
formations of 2 - 4. When low level (100 to 1500 agl, most commonly 300 -
500agl), they will normally *not* be receiving traffic information from
ATC.
When operating in a MOA, there may be intercept controllers who can call
out
glider traffic, but again, without a transponder, it is unlikely. The
formations will vary, but most pairs of flight lead and wingman will be
laterally spread by 5000 to 10000 feet, for visual lookout. The flight
lead
will be spending quite a bit of his time looking forward for threat
detection and navigation, but the wingman will be spending less time
looking
forward because he must maintain formation. If they see you, they have
an
excellent capability to avoid you. Head on and tail on, the sailplane
has
the tiny visual profile that fighter designers dream of.... In other
words,
you are nearly invisible unless you have a wing up in a turn/thermal.

5. As Kirk said, the primary threat is at 6 o'clock, because it is the
hardest to see - essentially, only the overtaking aircraft has a
reasonable
chance of avoiding a collision. Therefore, if you know you are operating
in
a high threat area: MOA, low level route, approach corridor, VFR flyway,
near an airport etc, I would "belly check" periodically, depending on the
nature of the threat. The timing is based on the amount of time it takes
for
the threat aircraft to close from outside visual range to hitting me from
the 6 o'clock position. I use visual ranges of 8nm for airliners, 5 nm
for
small commercial jets (corporate and regional jets) and fighters, and 3
nm
for light aircraft - adjust as your visual acuity and experience dictate.
I
use worst-case speeds as follows: airliner and small jets - 4 nm/min,
fighters - 8 nm/min, and light aircraft - 2.5 nm/min. Combing detection
ranges and times, I calculate: airliners - 2 min, small jets - 1 min and
15
sec, fighters - roughly 40 sec, and light planes - approx 1 min and 15
sec.
So... if you are straight and level for more than these times, there is
sufficient time for an aircraft to move from outside (my) visual range to
the same airspace as my (your) little pink body. As you would probably
guess, fighters are the worst case because of their relatively small size
and high closure rate. On the positive side, there are typically more
eyeballs with better acuity and better maneuverability involved.
Interestingly, small jets and light aircraft are not that far behind, as
far
as detection time is concerned. In my experience they are far less
likely
to see you than the fighters. The same is true for airliners, but
because
of their size you have more time to see them coming...

6. How to do a belly check: No, I don't hack a stopwatch, but I keep
the
above times in mind with respect to the likely threat for my area. My
primary threat is small jet/light aircraft that operate on various
highway/flyways and approach corridors. Away from these specific areas,
traffic density is extremely low. First clear your "new six" - if you
are
going to turn left, look to the area behind to the right 4 - 5 oclock
position - this will be your new blind spot. Next clear your new nose
position - this is where you are going to roll out. Finally make a 45
deg
turn to the left and visually clear your "old six", which is now at your
left 7 to 8 o'clock. Often/usually, a belly check can be incorporated
into
turns you are going to make anyway, for other reasons. When you
visually
clear, make sure you focus on something on the horizon, otherwise you are
only visually clearing out to an arms length. If I really need to hold a
straight line, I do the belly check as a gentle 45 deg turn to each side.

7. In a thermal, periodically check to the outside of your term to clear
your "new six". If there are other sailplanes with you in the thermal,
of
course they are the primary threats for midair, but you still need to
check
for other aircraft. Fortunately, you are easier to see while turning - as
long as the other pilots are looking...

8. Proximity to clouds. You need to think about what you are doing when
you are near cloudbase, in proximity to likely IFR traffic. If you are
500'
below cloudbase (perfectly legal), and an airliner descends out of the
cloud
at 250kt on his descent profile on collision course (perfectly legal),
there
may be as little as 20 seconds to impact. If you are tail on when this
happens - good luck. I'm sure no one would ever be right at cloudbase on
a
nice day, because that would violate the FARs - more importantly, you
are
"rolling the bones" every time you do this on a known approach corridor.

9. Conclusion. If you fly in a high airliner/small jet threat area and
can afford a transponder it will help other people see/avoid you. If
your
primary threat comes from military operations in MOAs, I would not spend
the
money on a transponder unless I knew those fighters have intercept/atc
controllers passing them information. The various TPAS - type devices
will
help your see/avoid efforts and should help in the case of fighters,
although the flight lead is likely the only one squawking in the
formation.
Only you/your club knows the primary threats for your particular
operating
area and you need to understand what they are. Taylor your altitude
awareness/cloud avoidance and belly check frequency to the nature of your
local area. Don't cede visual lookout/avoidance responsibility to
someone
else - ever. Sailplane right-of-way is a myth in most situations and a
comfort only to your survivors/legal counsel.

Hope this helps.

Glen

Jack, Glen is right. Airplanes were made to go fast. In fact some of
the stated speeds in these posts have been underspoken, if that's a
word. Sometimes coming into the DFW airpsace, say for instance on the
GREGG5 arrival, there is a fix where they mandate us to slow to 250
knots for spacing with other traffic.
During the quiet time of the day, the controller might say, "no speed
restriction", which tells the crew, hey I'm still above 10000msl, let's
go fast. That means I'm legally allowed to run it up to, VMO, the max
indicated airspeed for that altitude/aircraft. If I'm at 11000'msl, I'm
cleared to run it up to 340 knots for a short time, anticipating that
all of a sudden the controller is going to come back with a "descend to
5000" command, and I'm going to cold cock the thrust levers, pull out
the spoilers, and slow to the 250knots required below 10000'.
Jack are you coming for Labor Day Races?

Glen Kelley wrote:
Jack, I can't agree that this is negligence on the jet pilot's part - at
least not until the investigation is complete.

Sailplanes are very hard to see. We surprise each other from time to time
at much slower closure rates than any jet is going to see closing with a
sailplane. Failure to maintain visual separation is a given, but negligence
is a stretch until someone shows the Captain/FO of the corporate jet were
reading the newspaper, serving drinks to the pax, or something equally
unlikely in the descent phase.

As far as airliner speeds and routing go, who do you think is going to win
if the airline industry is going to have to slow down or otherwise adjust to
blend with sailplane traffic (read that burn more gas and arrive later)? My
bet is with the airlines and flying public. Think about all the airports
that are closed after new housing encroaches on the airport boundaries. As
a small interest group we need to pick our battles.

I have never flown at Minden, but it sounds like the local crowd clearly
understands what is at stake and have tried to be good neighbors. Since no
one was seriously hurt, perhaps the flying environment won't change much.

Glen



"Jack" wrote in message
ps.com...
I just spent the time to read this whole thread,. Only my friend and
former hangar mate, the Mosquito pilot from Houston, makes real sence.
If you cannot see and avoid in visual flight rules area... SLOW DOWN.
Failure to do so is irresponsible. We don't need transponders if we all
avoid each other and that requires time to see and react. To me this is
the equivalent of riding with my brother in Phoenix who likes to drive
90 on the freeway, tailgating impossibly close, and passing on both
shoulders. It's crazy. I only go with him if I'm driving these days.
What I fear is the jet pilot's neglegence will be paid for by lost
flying priviledges in the soaring community. The other piece is going
into an area of reputed heavy glider traffic. Shouldn't she have known
that? Perhaps slowing them down isn't realistic. Demanding that at
least one of them have his/her head out of the cockpit isn't, in my
opinion.

Jack Womack
PIK-20B N77MA (TE)

Bob, I know what your saying with regard to the aging eyes. It stinks.
With regard to the glass cockpit, the automation is wonderful stuff,
and if more people would learn to set it up, use it and look out the
window more, we'd all be better off. This means all of us,
powered/glider, as I too am guilty of playing with my glider toys while
zipping along on task.
Unfortunately, a lot of our pro pilot friends don't take the time to
fly wonderful GenAv ships like our gliders, and taildraggers, so what
do they want to do when they get to work, shut off the automation and
hand fly the beast. Been in the business for almost thirty years,
watching someone, now head down, hand fly an aircraft with millions of
dollars worth of automation play the High and the Mighty is not
impressive anymore.
When I go to work after a weekend of glider/taildragger play, at 200'
off the deck it's "autopilot on", until 50' over the numbers where I
disengage to land. We brief the approach while still in cruise, yes,
nitpickers, there is always the chance of change of runway, then it's
automation all the way down, keeping eyes going outside. For a VNAV
descent it's only two key strokes, for a FLC descent it's one. If
properly managed it's a thing of beauty to see how little the crew has
to do other than manage, and look outside. Watching guys who want to
play pilot, and turn off the automation in the terminal area, well now
your having to watch him/her, and the airplane. Just easier, to use the
automation at work, then go yank/bank the toys on the weekends!
With regard to item #4, I think "give way" applies to everybody,
especially who ever sees the other guy first, if there's time. Let's
not be "dead right" in interpreting the rules. Avoidance requires
insight provided by all parties involved. If we in our glider take off
thinking, those doggone engine powered beasts better get out of the
way, because the "law" says I own the road, then were as good as dead.
Pick up the phone, mike, our heads, and fly defensively.

Bob C wrote:
Like Jack, I just read the whole thread. 4 comments:

1. Remember, the most important glass in a glass cockpit
is above the instrument panel. I used to quote this
to airline pilots, but these days I find it appropos
for many gadget-oriented glider drivers.

2. If you're not seeing much traffic, you're just not
looking hard enough.

3. I tried the 10 point font 'o' at ten feet. Even
in light blue it was clearly visible. At age 46, it's
actually harder to see it at 10 inches! I see another
aircraft at 10 miles, I wish I could read my altimeter
to tell ATC where I am ;o)

4. The rules are see and avoid, and give way to the
glider. The PIC is responsible for knowing all pertinent
information about the intended flight. Adjusting speed
or flight path to avoid heavy glider traffic is not
just a good idea, it's the law.



At 04:42 01 September 2006, Glen Kelley wrote:
Ramy, I would agree. Mode A isn't completely worthless,
since at least the
airliner knows you are around. Clearly Mode C provides
more 'protection'.

Glen
'Ramy' wrote in message
roups.com...
Thanks Glen. I am not aware of any transponder equiped
glider not using
mode C. Seems like once you go through the hassle
and cost of
installing a transponder, the encoder is the easy
part. Mode A sounds
almost useless, more confusing then not. A mode A
transponder could
signal an alert to any airline crusing at 30K above.
Which baffles me - Why aren't modern transponders
already including
internal encoder??

Ramy

Glen Kelley wrote:
Ramy,

The problem is that TCAS will display you as a target
with altitude
unknown
(unless you have mode c with an encoding altimeter).
Therefore, TCAS
will
only call you out as traffic and display your position
without generating
a
Resolution Advisory (RA). We see this pretty often
as VFR traffic. We
will
be looking hard for the traffic, but won't necessarily
maneuver the
aircraft, since we can't see altitude/heading.

If in fact, the sailplane does have mode C with an
encoding altimeter,
then
the RA will be generated and you should see the big
bird maneuver to
avoid
the conflict. Note that a TCAS RA will direct maneuvering
in the
vertical
only, since TCAS azimuth is considered too innacurate
to generate
turn-based
avoidance. Typical RAs would be 'Climb,Climb, Climb
- Descend, Descend,
Descend - Reduce Climb - Reduce Descent, etc'.

I guess I figured most of the gliders with transponders
weren't using
Mode
C, so good catch.

Glen
'Ramy' wrote in message
ups.com...
Thanks for the excellent overview, Glen. Regarding
number 3, why would
a TCAS equipped airliner pilot need to see me if
the TCAS gives the
resolution? I'm pretty sure most of the airliners
vectored around me
never actually see me (although I always
wave ;-)

Ramy

Glen Kelley wrote:
A few additions to Kirk's excellent points - from
the background of
former
fighter pilot, current airline pilot, and current
glider pilot:

1. We often surprise each other in sailplanes with
how hard it is to
see
each other. Don't expect an airline pilot to be
any better at it!
The
fighter pilot at least will have good visual acuity
and is used to
looking
for small targets.

2. Airline pilots don't carry sectionals - at the
speeds we operate,
there
would be little time to use them anyway. Fighter
pilots will carry a
low
level map and will have thought about visual traffic
conflicts, wires,
terrain, etc in the planning stages. At the speeds
they operate, they
aren't looking at those maps very often, once airborne.

3. The busier glider operations are notam'd and often
referred to by
atc
controllers. If you have an operable transponder,
you will *normally*
be
called out by atc and if TCAS equipped, airline pilots
will be aware
of
your
location. They would still have to see you to maneuver
away from you.
(See
note 1.) Big airliners are not very maneuverable
(mine - the Boeing
737 -
is limited to 2.5 g!).

4. Fighters are a different case. They don't have
TCAS and only some
of
them have the ability to interrogate/detect transponder
targets. Some
of
them have air intercept radar capability, but sailplanes
are small
radar
targets and will often (usually!) be filtered out
because of their low
speeds and altitudes - like highway traffic. If
they are at low
altitude,
fighters usually operate at high speed (420 - 540
indicated, except
the
A-10). As Kirk pointed out they will almost never
be alone, but will
be
in
formations of 2 - 4. When low level (100 to 1500
agl, most commonly
300 -
500agl), they will normally *not* be receiving traffic
information
from
ATC.
When operating in a MOA, there may be intercept controllers
who can
call
out
glider traffic, but again, without a transponder,
it is unlikely. The
formations will vary, but most pairs of flight lead
and wingman will
be
laterally spread by 5000 to 10000 feet, for visual
lookout. The
flight
lead
will be spending quite a bit of his time looking
forward for threat
detection and navigation, but the wingman will be
spending less time
looking
forward because he must maintain formation. If they
see you, they
have
an
excellent capability to avoid you. Head on and tail
on, the sailplane
has
the tiny visual profile that fighter designers dream
of.... In other
words,
you are nearly invisible unless you have a wing up
in a turn/thermal.

5. As Kirk said, the primary threat is at 6 o'clock,
because it is
the
hardest to see - essentially, only the overtaking
aircraft has a
reasonable
chance of avoiding a collision. Therefore, if you
know you are
operating
in
a high threat area: MOA, low level route, approach
corridor, VFR
flyway,
near an airport etc, I would 'belly check' periodically,
depending on
the
nature of the threat. The timing is based on the
amount of time it
takes
for
the threat aircraft to close from outside visual
range to hitting me
from
the 6 o'clock position. I use visual ranges of 8nm
for airliners, 5
nm
for
small commercial jets (corporate and regional jets)
and fighters, and
3
nm
for light aircraft - adjust as your visual acuity
and experience
dictate.
I
use worst-case speeds as follows: airliner and small
jets - 4 nm/min,
fighters - 8 nm/min, and light aircraft - 2.5 nm/min.
Combing
detection
ranges and times, I calculate: airliners - 2 min,
small jets - 1 min
and
15
sec, fighters - roughly 40 sec, and light planes
- approx 1 min and 15
sec.
So... if you are straight and level for more than
these times, there
is
sufficient time for an aircraft to move from outside
(my) visual range
to
the same airspace as my (your) little pink body.
As you would probably
guess, fighters are the worst case because of their
relatively small
size
and high closure rate. On the positive side, there
are typically more
eyeballs with better acuity and better maneuverability
involved.
Interestingly, small jets and light aircraft are
not that far behind,
as
far
as detection time is concerned. In my experience
they are far less
likely
to see you than the fighters. The same is true for
airliners, but
because
of their size you have more time to see them coming...

6. How to do a belly check: No, I don't hack a
stopwatch, but I keep
the
above times in mind with respect to the likely threat
for my area. My
primary threat is small jet/light aircraft that operate
on various
highway/flyways and approach corridors. Away from
these specific
areas,
traffic density is extremely low. First clear your
'new six' - if you
are
going to turn left, look to the area behind to the
right 4 - 5 oclock
position - this will be your new blind spot. Next
clear your new nose
position - this is where you are going to roll out.
Finally make a 45
deg
turn to the left and visually clear your 'old six',
which is now at
your
left 7 to 8 o'clock. Often/usually, a belly check
can be incorporated
into
turns you are going to make anyway, for other reasons.
When you
visually
clear, make sure you focus on something on the horizon,
otherwise you
are
only visually clearing out to an arms length. If
I really need to
hold a
straight line, I do the belly check as a gentle 45
deg turn to each
side.

7. In a thermal, periodically check to the outside
of your term to
clear
your 'new six'. If there are other sailplanes with
you in the
thermal,
of
course they are the primary threats for midair, but
you still need to
check
for other aircraft. Fortunately, you are easier to
see while turning -
as
long as the other pilots are looking...

8. Proximity to clouds. You need to think about
what you are doing
when
you are near cloudbase, in proximity to likely IFR
traffic. If you
are
500'
below cloudbase (perfectly legal), and an airliner
descends out of the
cloud
at 250kt on his descent profile on collision course
(perfectly legal),
there
may be as little as 20 seconds to impact. If you
are tail on when
this
happens - good luck. I'm sure no one would ever
be right at cloudbase
on
a
nice day, because that would violate the FARs -
more importantly, you
are
'rolling the bones' every time you do this on a known
approach
corridor.

9. Conclusion. If you fly in a high airliner/small
jet threat area
and
can afford a transponder it will help other people
see/avoid you. If
your
primary threat comes from military operations in
MOAs, I would not
spend
the
money on a transponder unless I knew those fighters
have intercept/atc
controllers passing them information. The various
TPAS - type devices
will
help your see/avoid efforts and should help in the
case of fighters,
although the flight lead is likely the only one squawking
in the
formation.
Only you/your club knows the primary threats for
your particular
operating
area and you need to understand what they are. Taylor
your altitude
awareness/cloud avoidance and belly check frequency
to the nature of
your
local area. Don't cede visual lookout/avoidance
responsibility to
someone
else - ever. Sailplane right-of-way is a myth in
most situations and
a
comfort only to your survivors/legal counsel.

Hope this helps.

Glen

They are still 2000 Euros or £1500 before fitting,
testing, licensing and Value Added Tax. You can buy
a decent airworthy wooden glider for far less than
that in the UK!

If any anti-collision device of about the size, cost
and power consumption of a small portable GPS unit
becomes available, then I might be prepared to buy
one, especially if it doesn't require an externally
mounted aerial that reduces glider performance.

Derek Copeland

At 11:30 01 September 2006, W.J. \bill\ Dean \u.K.\.
wrote:
All the transponders currently listed by Filser
http://www.filser.de/onlineshop/english/ are modes
A/C and S, and have
extended squitter; they all have an integral alticoder.
These are probably
the cheapest on the UK market http://www.lxavionics.co.uk/
.

I would be surprised if this is not true of other makes,
I am sure it soon
will be.

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


'Ramy' wrote in message
oups.com...

Thanks Glen. I am not aware of any transponder equiped
glider not using
mode C. Seems like once you go through the hassle
and cost of
installing a transponder, the encoder is the easy
part. Mode A sounds
almost useless, more confusing then not. A mode A
transponder could
signal an alert to any airline crusing at 30K above.
Which baffles me - Why aren't modern transponders
already including
internal encoder??

Ramy