Batteries, Solar Panels, Transponders, etc.

[JS]

Onward.
It's time for serious discussion of Collision Avoidance Systems and
techniques.
There is no substitute for a good lookout. Don't install all this
instrumentation and expect to be able to fly blind.

These equipment-based topics come to mind immediately.

Batteries.
Solar panels.
Transponders.
Transponder antenna mounting.
Altitude encoders.
Alternatives, ie: FLARM.

and Use and Certification of transponder systems.

Some people are installing Lithium Ion batteries instead of traditional
Sealed Lead Acid. Your experience?
Any more thoughts on the benefits and dangers of Li-Po?

There are a few interesting photovoltaic panels available. For example,
a 5 Watt "Powersheet" can be mounted on the fuselage above the spar.

My only experience with transponders is the Becker ATC 4401 175 Watt
unit. It is easy to fit in a glider panel.
Eric Greenwell has written a great article on transponders. Look on
this web page.
http://www.soaringsafety.org/prevention/articles.html

Transponder antennas need to point down, have a large ground plane, and
have no metal or carbon between them and the outside.
Other mounting problems include clearing the tail of the trailer, and
proximity to the pilot.
I have the plans for an LS-6 antenna mount which goes behind the gear,
inside the fuselage.
The shop where my system was certified was very happy with the output
of the transponder.

The encoder I used was the ACK. It is small, light, comes with a mount,
and uses little electrical energy.

John Carlisle just posted a good review of some alternative systems.
http://groups.google.com/group/rec.aviation.soaring/browse_thread/thread/28e4fd1f9c29cf7d/073fca607295037b#073fca607295037b
I am installing an Oz-FLARM in my Australia-based glider. Every
aircraft in my club has one. See this article.
http://www.users.bigpond.com/keepitsoaring/nsw2005/img/OzFLARM1.pdf

If you install a transponder system, it must be turned on for the
duration of each flight. If the glider batteries are running low, I
would suggest contacting ATC and letting them know you need to turn it
off to maintain the rest of your instrument panel. Then they shouldn't
assume you fell out of the sky.
The transponder and altitude encoder neet to be certified every two
years. The glidere will not pass an annual inspection with an out of
date transponder.

Any experience with new technology or better use of old will be of help
to all who have ever considered flying with some sort of CAS.
Keep your eyes out the window.
Jim

[Marc Ramsey]

JS wrote:
> Some people are installing Lithium Ion batteries instead of traditional
> Sealed Lead Acid. Your experience?
> Any more thoughts on the benefits and dangers of Li-Po?

I've seen a few people use an auxiliary battery (and associated charger)
that was intended to be attached to the bottom of a laptop computer,
which should be fairly safe (ignoring the recent experiences of Dell and
Apple). If one is tempted to roll their own setup, I suggest they
search around for a few videos of shorted or overcharged Li-Po cells,
and ask themselves how many they want in the cockpit near them...

> The encoder I used was the ACK. It is small, light, comes with a mount,
> and uses little electrical energy.

I don't know about that particular encoder, but some consume very little
energy sitting in a nice warm hangar, but eat a lot more when the
temperature is 0C or below...

> If you install a transponder system, it must be turned on for the
> duration of each flight. If the glider batteries are running low, I
> would suggest contacting ATC and letting them know you need to turn it
> off to maintain the rest of your instrument panel. Then they shouldn't
> assume you fell out of the sky.

Gliders have a preassigned squawk in the Reno area, and the local ATC
folks are aware that a lot of gliders have limited battery capacity, so
they don't get uptight when we disappear...

Marc

[Andy[_1_]]

Marc Ramsey wrote:

the local ATC folks are aware that a lot of gliders have limited
battery capacity, so
they don't get uptight when we disappear...


Nevertheless an aircaft that has a transponder is required by the regs
to have it operating, or does it? Do Reno area gliders have an LOA
that exempts them?

ref 91.215 ... (c) Transponder-on operation. While in the airspace as
specified in paragraph (b) of this section or in all controlled
airspace, each person operating an aircraft equipped with an operable
ATC transponder maintained in accordance with §91.413 of this part
shall operate the transponder, including Mode C equipment if installed,
and shall reply on the appropriate code or as assigned by ATC.

So you can't use it unless it meets 91.413, but if it does it must be
on. The regulation is convoluted and and lawyers may disagree on
whether the exemption still applies after a transponder has been fitted
to an airctaft that didn't need to have it.


Andy

[Marc Ramsey]

Andy wrote:
> Marc Ramsey wrote:
>
> the local ATC folks are aware that a lot of gliders have limited
> battery capacity, so
> they don't get uptight when we disappear...
>
> Nevertheless an aircaft that has a transponder is required by the regs
> to have it operating, or does it? Do Reno area gliders have an LOA
> that exempts them?

Independent of the legality (and, I assume, it is not strictly legal),
discussions with Reno ATC over the years indicate that they would rather
we have transponders and turn them off outside of the high traffic area,
then not have them at all...

[Vaughn Simon]

"JS" > wrote in message
ups.com...
> These equipment-based topics come to mind immediately.
>
> Batteries.
> Solar panels.
> Transponders.
> Transponder antenna mounting.
> Altitude encoders.
> Alternatives, ie: FLARM.

Anytime you are discussing the combination of solar panels and batteries,
we also need to be discussing charge controllers. Since you have broached the
subject of Lithium Ion batteries, you would need to find a controller that is
approved for those batteries. Be aware that the dangers of Lion batteries,
largely (but not exclusively) concern charging.
>
>
> There are a few interesting photovoltaic panels available. For example,
> a 5 Watt "Powersheet" can be mounted on the fuselage above the spar.

Not to discourage PV panels, but you only get your entire five watts when the
entire panel is flat and pointed directly at full sunlight, and probably not
even then. With solar panels, always derate the manufacturer's claims by at
least 50% to approach real-life expectations of results. (As they say, your
mileage may vary)

Vaughn

>

[JS]

Vaughn Simon wrote:
>Anytime you are discussing the combination of solar panels and batteries,
> we also need to be discussing charge controllers.
> Vaughn

Thanks.
..
Yes, add PV charge controllers to the Liszt!
I bought one a while ago on E-Bay for $30. It works fine on SLA
batteries.
Jim

[bumper]

For sailplanes, there's an upside though. The PV manufacture's specs list
panel temperature for rated output. Since PV panels make more voltage at
colder temps, and as you go up it gets colder, you can turn this into more
power from a given PV array.

Assuming you pay just a bit more for your solar charge controller and buy a
Maximum Power Point Tracker type, your MPPT controller will trade the higher
output voltage for up to 30% more current from a given PV panel.

MPPT charge controllers, suitable for glider use, are available for under
$100.

bumper
purveyor of QuitVent & MKII "high tech" Yaw String
Minden, NV

"Vaughn Simon" > wrote in message
...
>
> "JS" > wrote in message
> ups.com...
>> These equipment-based topics come to mind immediately.
>>
>> Batteries.
>> Solar panels.
>> Transponders.
>> Transponder antenna mounting.
>> Altitude encoders.
>> Alternatives, ie: FLARM.
>
> Anytime you are discussing the combination of solar panels and
> batteries, we also need to be discussing charge controllers. Since you
> have broached the subject of Lithium Ion batteries, you would need to find
> a controller that is approved for those batteries. Be aware that the
> dangers of Lion batteries, largely (but not exclusively) concern charging.
>>
>>
>> There are a few interesting photovoltaic panels available. For example,
>> a 5 Watt "Powersheet" can be mounted on the fuselage above the spar.
>
> Not to discourage PV panels, but you only get your entire five watts when
> the entire panel is flat and pointed directly at full sunlight, and
> probably not even then. With solar panels, always derate the
> manufacturer's claims by at least 50% to approach real-life expectations
> of results. (As they say, your mileage may vary)
>
> Vaughn
>
>>
>
>

[Mike Schumann]

If you are out of juice, the transponder would not be "operable".

Mike Schumann

"Andy" > wrote in message
oups.com...

Marc Ramsey wrote:

the local ATC folks are aware that a lot of gliders have limited
battery capacity, so
they don't get uptight when we disappear...


Nevertheless an aircaft that has a transponder is required by the regs
to have it operating, or does it? Do Reno area gliders have an LOA
that exempts them?

ref 91.215 ... (c) Transponder-on operation. While in the airspace as
specified in paragraph (b) of this section or in all controlled
airspace, each person operating an aircraft equipped with an operable
ATC transponder maintained in accordance with §91.413 of this part
shall operate the transponder, including Mode C equipment if installed,
and shall reply on the appropriate code or as assigned by ATC.

So you can't use it unless it meets 91.413, but if it does it must be
on. The regulation is convoluted and and lawyers may disagree on
whether the exemption still applies after a transponder has been fitted
to an airctaft that didn't need to have it.


Andy