Trig TT21 Transponder ... reports?

On Aug 19, 10:18*pm, Darryl Ramm wrote:
On Aug 19, 8:13*pm, Mike Schumann
wrote:
[snip]





Every sport has leeching. *In Nascar you drive 2" off the leader's
bumper to reduce drag. *There's no problem as long it's a level playing
field and everyone has the same options.

We are NEVER going to get competitively priced equipment if everything
needs to be customized for the soaring community. *Anti-collision
hardware and software should be standardized for ALL aircraft. *Granted,
we have a unique style of flying that can cause excessive false alarms
in systems that aren't designed to recognize that.

That should be dealt with by working with the avionics industry to make
sure that everyone who is designing collision avoidance systems (from
TCAS II down to low end ADS-B enabled devices) understand the unique
characteristics of gliders and accommodate that in their algorithms.

Knowing the rate of climb or decent of aircraft that are in your
vicinity is very useful in evaluating whether or not they are a threat.
* As a pilot, I don't want to wait for an alarm just prior to an
imminent collision. *I want to see what is going on around me 1-2 miles
out, so I can avoid getting anywhere close to an uncomfortable
situation. *If I am entering a gaggle, I want to see what is happening
in 3D with the other gliders that are already there.

Artificially turning off this type of information is not going to go
over very well with the FAA, the NTSB, or the trial lawyers, the next
time there is a mid-air involving gliders in a contest with aircraft
equipped with this kind of equipment. *It's surprising that this
wouldn't be raising huge red flags with the FLARM guys given how
skittish they were about the US market due to the litigious nature of
our legal system.

--
Mike Schumann

Are you speaking for yourself alone or does this represent the option
of the SSA or other people within the SSA or Miter working on UAT
stuff? What is your involvement with the SSA on UAT technology?

All this contest oriented features that Flarm developed (largely as I
understand it at the request of (non-USA) contest pilots and I believe
the IGC) is meaningless in your world. How about letting the contest
pilots and their rules committees drive what they need and the
technology providers can work on meeting their needs not the other way
around. I can only guess what the USA rules committe wants in this
space, but I'd rather hear from them. But I gather you don't think
asking them what is worthwhile.

And a basic summary of you position on collision avoidance technology
is that -- we should not use stuff just because it works to solve a
particular problem (or some set of problems) because things that solve
particular problems that a small community of users have are bad
because they must be inherently expensive and to lower the cost
instead of minimizing the problem space you are trying to address with
a technology/product you maximuse the space, make the solution as
general as possible and the process as large and bureaucratic as
possible. You seem to believe this as a universal truth?

No consideration that probably one of the most effective, proven, bang
for the buck collision avoidance technologies in aviation is wait for
it... Flarm (and yes it cannot do everything, but duh that's a large
part of the reason it is so affordable and works so well for what it
is intended to do).

Getting things done is not about dogma of how things should be done,
the devil is in the details of trying to leverage standards and mass
market technology and working out how to affordable deliver a real
solution to real problems that real users have. That takes a team of
really bright people with a focus on solving real problems. If anybody
thinks they have a UAT based product that is going to compete in the
glider market they better actually better get out and solicit input
from target users on what they actually need and they ought to be
doing basic things like circulating trial balloon product specs to see
if they meet minimum market entry and competitive differentiation
requirements. But I gather there seems to be an opinion that this is
not needed. Is that just you or do other folks working on UATs in the
SSA believe this as well?

Darryl


I believe Mike has made the perfect argument for why the Soaring
community should standardize on PowerFlarm. His scale economies
argument fails as UAT transceivers are at least as expensive as
PowerFlarm for less functionality (the Mitre unit has no display, no
PCAS). The argument that trial lawyers would flock to sue contest
organizers if they required collision units to be turned off argues
strongly for PowerFlarm to be mandated since the lack of ADS-B
standards argues for a single standard. Plus imagine the field day the
lawyers would have if they knew that a soaring-specific technology was
available that solved for the highest probability threat and failed to
act on it - a clear case for negligence.

I have grown weary of the UAT spin - and to think that I used to be a
supporter.

9B

On 8/20/2010 12:18 AM, Darryl Ramm wrote:
On Aug 19, 8:13 pm, Mike
wrote:
[snip]
Every sport has leeching. In Nascar you drive 2" off the leader's
bumper to reduce drag. There's no problem as long it's a level playing
field and everyone has the same options.

We are NEVER going to get competitively priced equipment if everything
needs to be customized for the soaring community. Anti-collision
hardware and software should be standardized for ALL aircraft. Granted,
we have a unique style of flying that can cause excessive false alarms
in systems that aren't designed to recognize that.

That should be dealt with by working with the avionics industry to make
sure that everyone who is designing collision avoidance systems (from
TCAS II down to low end ADS-B enabled devices) understand the unique
characteristics of gliders and accommodate that in their algorithms.

Knowing the rate of climb or decent of aircraft that are in your
vicinity is very useful in evaluating whether or not they are a threat.
As a pilot, I don't want to wait for an alarm just prior to an
imminent collision. I want to see what is going on around me 1-2 miles
out, so I can avoid getting anywhere close to an uncomfortable
situation. If I am entering a gaggle, I want to see what is happening
in 3D with the other gliders that are already there.

Artificially turning off this type of information is not going to go
over very well with the FAA, the NTSB, or the trial lawyers, the next
time there is a mid-air involving gliders in a contest with aircraft
equipped with this kind of equipment. It's surprising that this
wouldn't be raising huge red flags with the FLARM guys given how
skittish they were about the US market due to the litigious nature of
our legal system.

--
Mike Schumann

Are you speaking for yourself alone or does this represent the option
of the SSA or other people within the SSA or Miter working on UAT
stuff? What is your involvement with the SSA on UAT technology?

All this contest oriented features that Flarm developed (largely as I
understand it at the request of (non-USA) contest pilots and I believe
the IGC) is meaningless in your world. How about letting the contest
pilots and their rules committees drive what they need and the
technology providers can work on meeting their needs not the other way
around. I can only guess what the USA rules committe wants in this
space, but I'd rather hear from them. But I gather you don't think
asking them what is worthwhile.

And a basic summary of you position on collision avoidance technology
is that -- we should not use stuff just because it works to solve a
particular problem (or some set of problems) because things that solve
particular problems that a small community of users have are bad
because they must be inherently expensive and to lower the cost
instead of minimizing the problem space you are trying to address with
a technology/product you maximuse the space, make the solution as
general as possible and the process as large and bureaucratic as
possible. You seem to believe this as a universal truth?

No consideration that probably one of the most effective, proven, bang
for the buck collision avoidance technologies in aviation is wait for
it... Flarm (and yes it cannot do everything, but duh that's a large
part of the reason it is so affordable and works so well for what it
is intended to do).

Getting things done is not about dogma of how things should be done,
the devil is in the details of trying to leverage standards and mass
market technology and working out how to affordable deliver a real
solution to real problems that real users have. That takes a team of
really bright people with a focus on solving real problems. If anybody
thinks they have a UAT based product that is going to compete in the
glider market they better actually better get out and solicit input
from target users on what they actually need and they ought to be
doing basic things like circulating trial balloon product specs to see
if they meet minimum market entry and competitive differentiation
requirements. But I gather there seems to be an opinion that this is
not needed. Is that just you or do other folks working on UATs in the
SSA believe this as well?


Darryl

I am speaking only for myself, a non-contest flying glider pilot and
commercial airline passenger.

Personally, I don't care how we get a comprehensive collision avoidance
system in the US (whether it is UAT, 1090ES or FLARM). The issue is
that see and avoid is not a reliable way to avoid collisions between
airplanes.

The problem is not just contests. Every day, we have near misses
between gliders, other aircraft, and jets. Everyone who has purchased a
PCAS unit knows full well how many aircraft are flying around that they
never see.

You have this attitude that the only people who care about this problem
are the FLARM guys. You completely ignore the significant efforts that
have been made by many people in the SSA, MITRE, AOPA, and even the FAA
to try to get the bureaucracy to address the mid-air threats in the GA
and glider world.

This summer, the SSA, AOPA, and the FAA were conducting operation tests
in the DC area to demonstrate the effectiveness of low cost ADS-B
transceivers in gliders to help reduce the threat of mid-air collisions.
A major irony and tragedy was the mid-air that killed Chris
O’Callaghan, who was an enthusiastic participant in this demonstration
project.

It is very frustrating that Chris's death has not brought together the
leadership of the SSA, AOPA, and the FAA to really get their hands
around a strategy to get these systems deployed in an expedited manner.

The ultimate goal that we should all be be working towards is that every
aircraft, including gliders, balloons, jets, and even parachutists,
should be electronically visible to all other aircraft. That visibility
should extend far enough that everyone can avoid other aircraft to their
own comfort level. The 172 on a point to point excursion flight is
going to probably be much more interested in avoiding other aircraft
than a glider pilot participating in a contest. A jet is going to want
to have an even wider safety margin.

Obviously in a high traffic environment, like a contest, you want to
have an intelligent system that minimizes false alarms. If you don't do
that, then the alarms become meaningless and will be ignored. That is a
legitimate goal.

However, arbitrarily turning off position data, just to enhance the
competitive nature of an event, without any further justification, would
certainly result in some serious scrutiny, if this was a contributing
factor to an accident.

If the accident was between contest participants, all of whom agreed to
this arrangement, there might be a defense. However, if the accident
involved another aircraft that just happened to be in the area, a good
trial lawyer could certainly make a serious case against the pilots
involved, as well as the contest organizers, any governing bodies that
created rules that contributed to the accident, as well as any avionics
manufacturer that artificially suppressed data that could have been
helpful without any legitimate justification.

Unfortunately, I don't think that this whole FLARM debate is moving us
any closer to widespread deployment of collision avoidance systems in
gliders. What I see is a very narrow focus on a quick band-aid to try
to help the contest environment, while we continue to ignore a
comprehensive solution to the bigger problem.

--
Mike Schumann

P.S. I do have a legal background.

On Thu, 19 Aug 2010 18:19:24 -0700, Darryl Ramm wrote:

BTW I don't want to get sidetracked here but the current USA rules have
not kept track with technology and as a result are strange in how they
do not for example strictly prohibit an ADS-B traffic receiver (since it
is not a "two-way communication device"), but by banning "two-way
communication devices" they do currently prohibit Flarm based devices.

I'm realising there is another passive collision warning system that we
use in the UK but I think may not be used as such in the USA - NOTAMS.

Whenever there's something happening here that raises a significant
collision risk such as a balloon festival, gliding competition or
microlite rally it will be NOTAMed, giving the base airfield, number of
participants and the area where significant numbers of participating
aircraft may be found. This at least warns other pilots to be more
vigilant in that area.

I've noticed that NOTAMs seem to be much less used in the USA than they
are here, so I'm wondering if your Regionals and national competitions
are routinely NOTAMed.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Aug 20, 12:50*am, Mike Schumann
wrote:
On 8/20/2010 12:18 AM, Darryl Ramm wrote:

Personally, I don't care how we get a comprehensive collision avoidance
system in the US (whether it is UAT, 1090ES or FLARM).

Your arguments (even later in this same post) belie this statement.

The problem is not just contests. *Every day, we have near misses
between gliders, other aircraft, and jets. *Everyone who has purchased a
PCAS unit knows full well how many aircraft are flying around that they
never see.

PCAS is an important adjunct technology for the immediate future -
PowerFlarm has it but Navworx and Mitre units don't and therefore
can't see anything but ADS-B UAT direct outside the very limited
ground station deployment. Which meant you won't be able to see 1090ES
equipped jets unless you are near ground stations taht are yet to be
built (or even funded to be built I suspect) Correct?

You have this attitude that the only people who care about this problem
are the FLARM guys. *You completely ignore the significant efforts that
have been made by many people in the SSA, MITRE, AOPA, and even the FAA
to try to get the bureaucracy to address the mid-air threats in the GA
and glider world.

I think the point is that Flarm (and PowerFlarm by extension) has done
a much better job of actually solving for the primary glider collision
scenarios in a unit you can order today (and will likely be delivered
in time for next season) - that is why people are getting interested
in it. For instance, and as has been pointed out, the Navworx unit is
more expensive and draws 0.8 amps @ 12v before you add a GPS or
display. That likely doubles or triples the power requirements on most
gliders. We can recognize the efforts of Mitre and Navworx all we
want but the fact remains they are FAR more focused on GA than gliders
- a look at what they are producing confirms that.

This summer, the SSA, AOPA, and the FAA were conducting operation tests
in the DC area to demonstrate the effectiveness of low cost ADS-B
transceivers in gliders to help reduce the threat of mid-air collisions.

Good for them, but it's mostly not material to the discussion of which
products now coming on the market are most suitable for gliders. Just
because it works in an operational test doesn't mean its the BEST
solution.

It is very frustrating that Chris's death has not brought together the
leadership of the SSA, AOPA, and the FAA to really get their hands
around a strategy to get these systems deployed in an expedited manner.

True - it's further evidence of how hard it is to get bureaucracies
with diverse interests to align. It gives strength to the argument
that a blanket approach is highly unlikely to end up producing a
superior solution to PowerFlarm and its successors.

The ultimate goal that we should all be be working towards is that every
aircraft, including gliders, balloons, jets, and even parachutists,
should be electronically visible to all other aircraft. *That visibility
should extend far enough that everyone can avoid other aircraft to their
own comfort level. *The 172 on a point to point excursion flight is
going to probably be much more interested in avoiding other aircraft
than a glider pilot participating in a contest. *A jet is going to want
to have an even wider safety margin.

Ultimate goals are nice but having a solution that works before 2020
would be better. For 2011 that is likely PowerFlarm or PowerFlarm plus
a Trig TT21/22 (or similar). The latter seems pretty future-proofed
too. I don't think the Navworx unit does me much good until the ground
infrastructure is built out over the next 10-20 years (particularly in
the remote deserts and ridges where many of us in the west fly). And
with UAT I may never get a solution for jets with 1090ES in those
areas.

Obviously in a high traffic environment, like a contest, you want to
have an intelligent system that minimizes false alarms. *If you don't do
that, then the alarms become meaningless and will be ignored. *That is a
legitimate goal.

It's the highest priority goal for many of us.

However, arbitrarily turning off position data, just to enhance the
competitive nature of an event, without any further justification, would
certainly result in some serious scrutiny, if this was a contributing
factor to an accident.

You need to look in detail at how contest mode works on PowerFlarm -
it does not turn off collision warnings, it simply makes it harder to
use it to find other gliders who are climbing better than you. Making
it harder for gaggle to form is a significant addition to safety. If
you ignore the human behavioral implications of rules you are left
only with theoretical rules that have limited practical value.

If the accident was between contest participants, all of whom agreed to
this arrangement, there might be a defense. *However, if the accident
involved another aircraft that just happened to be in the area, a good
trial lawyer could certainly make a serious case against the pilots
involved, as well as the contest organizers, any governing bodies that
created rules that contributed to the accident, as well as any avionics
manufacturer that artificially suppressed data that could have been
helpful without any legitimate justification.

This is how lawyers kill innovation - by making theoretical arguments
about specious causality.

Unfortunately, I don't think that this whole FLARM debate is moving us
any closer to widespread deployment of collision avoidance systems in
gliders. *What I see is a very narrow focus on a quick band-aid to try
to help the contest environment, while we continue to ignore a
comprehensive solution to the bigger problem.

I think the proposal on the table was to do just the opposite - drive
widespread adoption of PowerFlarm in the US rather than wait for UAT,
which is of more questionable value in glider-glider scenarios,
doesn't yet have the critical ground stations to make it work, and may
never work in seeing 1090ES jets in remote locations.

--
Mike Schumann

P.S. *I do have a legal background.

You style of argument is consistent with that Mike. Are you sure you
don't have a financial interest in UAT adoption?

On Aug 20, 7:14*am, Andy wrote:
On Aug 20, 12:50*am, Mike Schumann
wrote:

On 8/20/2010 12:18 AM, Darryl Ramm wrote:
Personally, I don't care how we get a comprehensive collision avoidance
system in the US (whether it is UAT, 1090ES or FLARM).

Your arguments (even later in this same post) belie this statement.

The problem is not just contests. *Every day, we have near misses
between gliders, other aircraft, and jets. *Everyone who has purchased a
PCAS unit knows full well how many aircraft are flying around that they
never see.

PCAS is an important adjunct technology for the immediate future -
PowerFlarm has it but Navworx and Mitre units don't and therefore
can't see anything but ADS-B UAT direct outside the very limited
ground station deployment. Which meant you won't be able to see 1090ES
equipped jets unless you are near ground stations taht are yet to be
built (or even funded to be built I suspect) Correct?

You have this attitude that the only people who care about this problem
are the FLARM guys. *You completely ignore the significant efforts that
have been made by many people in the SSA, MITRE, AOPA, and even the FAA
to try to get the bureaucracy to address the mid-air threats in the GA
and glider world.

I think the point is that Flarm (and PowerFlarm by extension) has done
a much better job of actually solving for the primary glider collision
scenarios in a unit you can order today (and will likely be delivered
in time for next season) - that is why people are getting interested
in it. *For instance, and as has been pointed out, the Navworx unit is
more expensive and draws 0.8 amps @ 12v before you add a GPS or
display. That likely doubles or triples the power requirements on most
gliders. *We can recognize the efforts of Mitre and Navworx all we
want but the fact remains they are FAR more focused on GA than gliders
- a look at what they are producing confirms that.

This summer, the SSA, AOPA, and the FAA were conducting operation tests
in the DC area to demonstrate the effectiveness of low cost ADS-B
transceivers in gliders to help reduce the threat of mid-air collisions..

Good for them, but it's mostly not material to the discussion of which
products now coming on the market are most suitable for gliders. Just
because it works in an operational test doesn't mean its the BEST
solution.

It is very frustrating that Chris's death has not brought together the
leadership of the SSA, AOPA, and the FAA to really get their hands
around a strategy to get these systems deployed in an expedited manner.

True - it's further evidence of how hard it is to get bureaucracies
with diverse interests to align. It gives strength to the argument
that a blanket approach is highly unlikely to end up producing a
superior solution to PowerFlarm and its successors.

The ultimate goal that we should all be be working towards is that every
aircraft, including gliders, balloons, jets, and even parachutists,
should be electronically visible to all other aircraft. *That visibility
should extend far enough that everyone can avoid other aircraft to their
own comfort level. *The 172 on a point to point excursion flight is
going to probably be much more interested in avoiding other aircraft
than a glider pilot participating in a contest. *A jet is going to want
to have an even wider safety margin.

Ultimate goals are nice but having a solution that works before 2020
would be better. For 2011 that is likely PowerFlarm or PowerFlarm plus
a Trig TT21/22 (or similar). The latter seems pretty future-proofed
too. I don't think the Navworx unit does me much good until the ground
infrastructure is built out over the next 10-20 years (particularly in
the remote deserts and ridges where many of us in the west fly). And
with UAT I may never get a solution for jets with 1090ES in those
areas.

Obviously in a high traffic environment, like a contest, you want to
have an intelligent system that minimizes false alarms. *If you don't do
that, then the alarms become meaningless and will be ignored. *That is a
legitimate goal.

It's the highest priority goal for many of us.

However, arbitrarily turning off position data, just to enhance the
competitive nature of an event, without any further justification, would
certainly result in some serious scrutiny, if this was a contributing
factor to an accident.

You need to look in detail at how contest mode works on PowerFlarm -
it does not turn off collision warnings, it simply makes it harder to
use it to find other gliders who are climbing better than you. Making
it harder for gaggle to form is a significant addition to safety. *If
you ignore the human behavioral implications of rules you are left
only with theoretical rules that have limited practical value.

If the accident was between contest participants, all of whom agreed to
this arrangement, there might be a defense. *However, if the accident
involved another aircraft that just happened to be in the area, a good
trial lawyer could certainly make a serious case against the pilots
involved, as well as the contest organizers, any governing bodies that
created rules that contributed to the accident, as well as any avionics
manufacturer that artificially suppressed data that could have been
helpful without any legitimate justification.

This is how lawyers kill innovation - by making theoretical arguments
about specious causality.

Unfortunately, I don't think that this whole FLARM debate is moving us
any closer to widespread deployment of collision avoidance systems in
gliders. *What I see is a very narrow focus on a quick band-aid to try
to help the contest environment, while we continue to ignore a
comprehensive solution to the bigger problem.

I think the proposal on the table was to do just the opposite - drive
widespread adoption of PowerFlarm in the US rather than wait for UAT,
which is of more questionable value in glider-glider scenarios,
doesn't yet have the critical ground stations to make it work, and may
never work in seeing 1090ES jets in remote locations.

--
Mike Schumann

P.S. *I do have a legal background.

You style of argument is consistent with that Mike. *Are you sure you
don't have a financial interest in UAT adoption?

First off, thanks to the people who actually answered the original
question posed in the first post of this thread. Second, thanks to
those who fired up the PCAS, Flarm, PowerFlarm, UAT, 1090ES, and ADS-B
debate. I am VASTLY better informed now than when I started looking
into the whole transponder thing*. After reading every post in this
thread, and most of those in a couple other threads, here's MY take:
Flarm and PowerFlarm appears to be the only NEAR TERM solution to
glider on glider. Power requirements and cost fall within the range of
acceptance for glider pilots who fly in GLIDER congested areas.
UAT may serve well - in the future, but doesn't appear suited for the
soaring contest glider-on-glider scenario. Power requirements are on
the extreme upper edge of acceptable. Cost is also a factor, since it
will require a different transmitter. Oh, and another antenna.
1090ES ADS-B, etc. 2020 will arrive in 9 years and 4 months. From my
understanding, that's when the requirement for a 'certified' GPS feed
becomes mandatory. REALLY?? NINE YEARS!! Whatever 'requirement' is
written now, WILL be obsolete in nine years. Unfortunately, if past
experience is any indicator, the gummint folks who wrote the
'requirement' will have inadvertantly written it is such a way as to
legally demand use of the outdated technology, at a vastly higher cost
than using what will (in 2020) be current, superior technology.
Me, I just want the airliners to be aware of me, and the Trig is the
lowest power draw, least expensive solution to THAT problem.



*of course, starting at zero knowledge, anything gained is a vast
improvement!

On Fri, 20 Aug 2010 07:14:01 -0700, Andy wrote:

draws 0.8 amps @ 12v

I've not been near an airfield for 10 years now, but are there no
advances in solar power/battery technology since then that improve a
glider's power supply? What is a typical glider's current requirement?

--
Alex

The ADS-B Ground Station roll-out is moving forward at an accelerating
rate and should be completed Nation Wide by the end of 2012. It is
fully funded and all the necessary contracts are in place.

The vast majority of the country will have coverage above 1,800 ft. See
http://www.faa.gov/about/office_org/...cast/coverage/

I have no financial interest in any of this.

--
Mike Schumann

On Aug 20, 11:33*am, Alex Potter wrote:
On Fri, 20 Aug 2010 07:14:01 -0700, Andy wrote:
draws 0.8 amps @ 12v

I've not been near an airfield for 10 years now, but are there no
advances in solar power/battery technology since then that improve a
glider's power supply? What is a typical glider's current requirement?

--
Alex

I run my whole panel on less than 0.8 amp average. PDA, logger,
vario, radio. I use a 14 AH battery, useful capacity about 10 AH,
adding 0.8 amp would take me down to about 6 hours duration. I'd have
to add another battery somewhere to get my target 10 hour capacity.
Solar would be an option... but dang those things are ugly on a pretty
glider.

0.8 amps isn't a deal breaker for me... but less is better.

The Navworx product isn't generating any interest here because there
is at present no way to build a complete system out of the thing that
will work in a glider flown in proximity to other gliders. Possibly
someone like Flarm could do this... but the price point is going to be
difficult, $2500 transceiver, plus whatever additional for a display
and software... I don't see that catching on.

-Evan Ludeman / T8

It's a no-brainer. Everyone who flies gliders with other gliders
needs to get a PowerFlarm. Everyone who shares airspace with
airliners needs to get a transponder. It's just that simple.

The SSA rules committee needs to immediately adopt a mandate for
PowerFlarm in 2011 sanctioned contests so that the Flarm folks
understand their mission and can get production ramped accordingly.
Let's not have any more mid-airs -- they are ruining the fun.

A big thank you to Darryl for his extrodinarily clear explainations of
a complex subject.

On Aug 20, 8:33*am, Alex Potter wrote:
On Fri, 20 Aug 2010 07:14:01 -0700, Andy wrote:
draws 0.8 amps @ 12v

I've not been near an airfield for 10 years now, but are there no
advances in solar power/battery technology since then that improve a
glider's power supply? What is a typical glider's current requirement?

--
Alex

On Aug 20, 8:33 am, Alex Potter wrote:
On Fri, 20 Aug 2010 07:14:01 -0700, Andy wrote:
draws 0.8 amps @ 12v

I've not been near an airfield for 10 years now, but are there no
advances in solar power/battery technology since then that improve a
glider's power supply? What is a typical glider's current requirement?

--
Alex

With gliders we fly you cannot easily stick solar panels over large
areas of the glider because of cost and critical aerodynamic concerns
and concerns about solar heating the underlying composite structure.
There are specialized solar project exceptions. The manufacturer who
dominates solar panels for gliders today is Strobl (http://www.strobl-
solar.de ) and their panels are available preinsalled from all leading
glider manufacturers or as add-on for a large number of gliders. See
my blog at http://www.darryl-ramm.com/2007/01/s...or-sailplanes/
for what a retrofit kit looks like.

They typically deliver 15-30 watt maximum for several thousand dollars
outlay. The Stobl systems use crystalline wafers in a semi-flexible
ETFE (hey that what is used on Trefzel wire, oops another thread...)
type plastic encapsulation. Likely all hand-built. The panels are
attached with 3M ultra-high-bond double sided tape. Some installations
will have molded in recesses for the panels some use hand applied
filleting, some wedge trim strips around the panels. The crystalline
cells give relatively high efficiency even with only partial fill
factor on the panels. Other options emerging might be to use amorphous
thin film panels but you are typical starting with low efficiency. I
have the larges set of Strobl panels I can get on my ASH-26E engine
bay doors that gives a peak spec of 30W (2.5A @ 12V). The actual
delivered power is *much* lower. And you should rely not plan on solar
panels to significantly boost battery capacity for a single flight as
output drops dramatically under cloud streets, overcast sky etc. I
really like the Strobl panels but it may be more useful/safer to think
of them for use for ground charging of a tied down glider (e.g. some
airports have issues with separate panels near the aircraft when tied
down) and as a way of stretching capacity over several days when usual
ground charging infrastructure is not available.

Although it obviously varies widely a typical power consumption number
for a glider avionics is roughly around 0.8 amp (as Evan noted his is)
for what I am guessing is a typical setup of C302 style computer, a
PDA, and VHF radio. Owners should measure and calculate the loads in
the glider and estimate the battery capacity needed or run time
available from the batteries they have. Do not just divide the nominal
"Ah capacity" by amp load, especially at higher loads, you need to use
the discharge curves data from a manufacturer to estimate the
available run time of a battery at a particular load (most good VRLA
batteries are close enough to use another manufacturers spec sheet for
a similar sized battery).

Transponders (and their encoders) used to be considered a large power
hog. And in the days of horse drawn buggies, steam locomotives and
traveling wave tube amplifiers etc. they were. While they are much
more efficient nowadays, you do need to make sure they fit within a
ships power budget. Modern transponders range in power consumption
from ~0.5A for a Becker 4401 175W and ACK A30 encoder to around ~0.3A
for a Trig TT21 (with built in encoder). Transponder power consumption
will vary depending on interrogation rates and temperature (for the
encoder heater). i.e. The Trig TT21 uses less power than large PDAs
like the iPAQ 4700. The numbers here are realistic for typical glider
operations.

The NavWorx ADS600-B specs implies it consumes 0.8A at 12V. I have no
idea if this is accurate or not, it may be less in practice. Today you
need a separate display with third party software to get traffic
information/warnings from the device, so guess around 0.45A (e.g. for
a iPAQ 4700 PDA dedicated to the UAT data display).

Most gliders have some combination of one or more "7Ah" or "12Ah" VRLA
batteries. So to give a rough idea of maximum run time from typical
single batteries ... (These number are very rough, I don't have my
discharge spreadsheet handy that will do this properly, but they give
the flavor.)

2.0A load = guess of typical glider load + NavWorx ADS-600B + iPAQ
4700 for UAT traffic display
@2.0Ah load a typical "7Ah" VRLA battery ~ 2.7 hours
@2.0Ah load a typical "12Ah" VRLA battery ~ 5.2 hours

---

Since one scenario is people with Mode C might go UAT vs. buy a new
Mode S/1090ES capable transponder. A UAT is does not make a glider
visible on TCAS, so if you fly near airliners or fast jets that
transponder is a good idea. If you do not then just look at the
numbers above)

2.5A load = guess of typical glider load + Becker Mode C + ACK30 +
NavWorx ADS600-B + iPAQ 4700 for UAT traffic display
@2.5Ah load a typical "7Ah" VRLA battery ~ 2.2 hours
@2.5Ah load a typical "12Ah" VRLA battery ~ 4.1 hours

---

All these are numbers are for effectively fully discharging the
battery, you should really not plan on running down batteries this
much on typical flights and having no safety margin. Some fudge (20%)
should be deducted from these numbers for typical battery aging. For
very cold flights (e.g. wave) then maybe halve these run times. And
again do the real calculations for your actual setup.

How much battery capacity do you need? My longest flight was 8-9 hours
(in my old glider with no solar panel). A typical "serious" XC flight
for me is around 5-6 hours.

This all assumes the the NavWorx ADS600-B nominal 0.7A spec at 14VDC
nominal (i.e. 0.8A at 12VDC) is correct. It could be lower in
practice. I'm not even sure why we are down this rat hole. None of
this is not a slight on NavWorx, their UAT transceiver was not
designed for the glider market, NavWorx does not claim it is intended
for the glider market, or target any marketing to the glider market
AFAIK. And issues with incompatibility with all existing (Flarm serial
display protocol based) glider traffic display/software, lack of any
third party traffic display/warning product tuned for glider specific
type environments (esp. gaggles), lack of traffic collision/alert
warning from the receiver box etc. are also issues for use in the
glider market. I am convinced that a company who wanted to target the
USA glider marker with a UAT product would have no deep technical
issues addressing these items, or reducing the power consumption
significantly today. The issue is justifying a business case for a
company to do that for the intersection of the relatively small USA
UAT market and the much smaller USA glider market.

BTW some older slides and spreadsheets on glider batteries at
http://www.darryl-ramm.com/glider-batteries/ but I don't think these
make much sense unless you've seen me present them. I originally made
that presentation because of confusion around batteries and
transponders. That confusion went both ways, people way under capacity
for their loads (BTW interestingly often with PDAs and ClearNav type
devices not just transponders) and people thinking they could never
use a transponder, often based on out of date info on transponder
power requirements.

Darryl