Mechanical Vario

[Jeff Runciman]

This question was posted earlier but I was hoping for
a few more responses.

Do I put a mechanical vario or do I save space on the
panel.

Would love to hear what people have in their panel.

Jeff

[Bob Whelan[_2_]]

Jeff Runciman wrote:
> This question was posted earlier but I was hoping for
> a few more responses.
>
> Do I put a mechanical vario or do I save space on the
> panel.

Apparently I feel a need to start a religious war...

Electron movement can cease (open circuit, low battery, component
failure), become too energetic (short), pneumatics can fail (blockage,
leak). Everything has a life.

Which failure modes have you encountered most often? Which have you
heard people complain about most frequently? Have you ever heard of a
mechanical vario *suddenly* dying from an internal (i.e. non-pneumatic)
cause? Do you feel comfortable with all your panel eggs in an
electronic basket? How much thought to true redundancy have you given?

Your answers to questions as these may clarify your views.

Any approach is a double-edged sword, and there will be some who
(rightly) point out that frequency of failure is somewhat related to
frequency of use...and these days (both discrete-component based and
IC-basd) electrics are ubiquitous in sailplanes, and thus a
frequency-of-failure based assessment is to some extent invalid. That
noted, when I got into soaring, electric varios were still a newfangled
item, yet despite the relatively low frequency of them in panels, there
seemed to me to be an inordinate frequency of complaints about electric
(radio, cario) failures. IMHO, that's still true today, probably
because electric systems are: a) ubiquitous, b) seemingly simple and
relatively foolproof for any basically-educated-hack to implement, but
c) are in fact complex (chemically, physically, electronically,
conceptually).

Each of my personally-owned sailplanes when purchased had real
electrical systems in them, including the one I've flown since 1981.
Eventually its radio died, then its (uncompensated, used only for audio)
Ball electric vario. Today I use a handheld radio, and one day I hope
to remember to borrow my wife's Malletec for its audio. Only one person
ever has criticized my thermal etiquette (his experienced passenger
later privately told me he disagreed with the criticism), and my fun
meter has never felt seriously handicapped by the absence of electronic
input. My Sage continues to work perfectly, accompanied by the usual
A/S, (sticky) altimeter, and (little-used) whiskey compass. There are
at least three naked instrument holes in the panel.

Sometimes I feel like a dinosaur.

Regards,
Bob - a K.I.S.S. fan - Whelan

[Bill Daniels]

"Jeff Runciman" > wrote in message
...
> This question was posted earlier but I was hoping for
> a few more responses.
>
> Do I put a mechanical vario or do I save space on the
> panel.
>
> Would love to hear what people have in their panel.
>
> Jeff
>

I think most people would agree that a backup vario is needed. They would
disagree whether the backup should be mechanical or electronic. I chose a
Borgelt B40 electronic vario as a backup since it has an internal backup
battery, audio and averager.

As to whether electronic or mechanical varios are more reliable, I have 4
varios in my "Cabinet of Ancient Instruments". Three are mechanical and one
is electronic. All still work except that the mechanical instruments all
indicate +1 Kt. due to the radium paint on the needles becoming lighter with
age.

Any technology can fail but happily, failures are very rare in today's
instruments.

Bill Daniels

[Martin Gregorie[_1_]]

Jeff Runciman wrote:
> This question was posted earlier but I was hoping for
> a few more responses.
>
> Do I put a mechanical vario or do I save space on the
> panel.
>
> Would love to hear what people have in their panel.
>
What's already on your panel?

I have an SDI C4 with a Borgelt B.40 as backup (it has a 9v battery as
emergency power). I initially had a PZL mechanical as backup, but Mike
Borgelt recommends that you don't mix capacity (flow rate) instruments
with pressure sensing instruments on the same TE probe. The full story
is here:

http://www.borgeltinstruments.com/instrumentinstallation.pdf

on page 3 under "Pneumatic". Consequently I's just decided to swap the
PZL for a pressure sensing instrument when a used B.40 became available.
I'm very pleased with it. Its easy to read, has a fast response, and
complements the C4 very nicely. The B.40 is excellent for finding lift
while the C4 is very good for centering up thermals and for
inter-thermal cruise.


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

[Brian[_1_]]

After flying most of an afternoon on just the Mechanical, after my
electric failed, I purchased a B40. I really like having the Audio on
my Backup Vario.

Brian
CFIIG/ASEL
HP16T N16VP

[Dan G]

On Sep 23, 6:25 pm, Jeff Runciman >
wrote:
> Do I put a mechanical vario or do I save space on the
> panel?

Another way of asking the question could be "who has ever had their
primary vario fail?"

If my primary (electric audio) vario failed it most likely be because
of a general power failure, which would have also have left me without
radio, GPS and logger. If I did want to use a mechanical vario, I'd
have to go "heads down", which is something I just won't do. I'd fly
home via the seat of my pants.

So, no mechanical vario here.

I did once have a battery go flat on me as the previous pilots of this
club aircraft had not put the battery on charge and I'd not checked
the voltage during the DI - I learnt a lesson there. On another
occasion with another club aircraft the electric vario had broken but
it took a long time for it to be fixed and people were still getting
it out - I turned down flying it. Not interested in thermalling while
looking at a dial.


Dan

[Tony Verhulst]

Jeff Runciman wrote:
> This question was posted earlier but I was hoping for
> a few more responses.
>
> Do I put a mechanical vario or do I save space on the
> panel.

Just today, The vario indicator of my Cambridge 302 started pointinng
every which way except what was really happening (just after I told some
one how reliable it's been for the last 5 years :-) ), the audio worked
just fine. It sure was nice to have my Winter mechanical - although a
good electronic vario would have sufficed as well.

Tony V

[ContestID67]

I agree that having two varios is a must. 1) Electronic/electric/
audio as audio is invaluable. 2) Mechanical because it just won't
fail.

A side benefit is that my Cambridge 302 electronic vario is small
2-1/2" while my Mechanical is large 3-1/4". Thus I find myself
glancing at my large mechanical as it is easier to read but listen to
my electronic vario as it is easier to listen to ;-)

Best of both worlds.

- John "67R" DeRosa

[Roger Worden]

Just recently I experienced a low battery situation which affected the
electronic vario in my club ship. The vario did not just fail, it started
giving me unreasonable readings. Eventually I figured it out when the needle
started swinging wildly - I knew the battery was getting low but it took a
few minutes to recognize the wierd behavior. The ship did not have a backup
vario installed, but I had an electronic micro-vario clipped to my hat.
DEFINITELY have a backup of some sort if you're going cross-country... as
others said, the choice of type is up to you.

Roger

"Bob Whelan" > wrote in message
...
> Jeff Runciman wrote:
>> This question was posted earlier but I was hoping for
>> a few more responses.
>>
>> Do I put a mechanical vario or do I save space on the
>> panel.
>
> Apparently I feel a need to start a religious war...
>
> Electron movement can cease (open circuit, low battery, component
> failure), become too energetic (short), pneumatics can fail (blockage,
> leak). Everything has a life.
>
> Which failure modes have you encountered most often? Which have you heard
> people complain about most frequently? Have you ever heard of a
> mechanical vario *suddenly* dying from an internal (i.e. non-pneumatic)
> cause? Do you feel comfortable with all your panel eggs in an electronic
> basket? How much thought to true redundancy have you given?
>
> Your answers to questions as these may clarify your views.
>
> Any approach is a double-edged sword, and there will be some who (rightly)
> point out that frequency of failure is somewhat related to frequency of
> use...and these days (both discrete-component based and IC-basd) electrics
> are ubiquitous in sailplanes, and thus a frequency-of-failure based
> assessment is to some extent invalid. That noted, when I got into
> soaring, electric varios were still a newfangled item, yet despite the
> relatively low frequency of them in panels, there seemed to me to be an
> inordinate frequency of complaints about electric (radio, cario) failures.
> IMHO, that's still true today, probably because electric systems are: a)
> ubiquitous, b) seemingly simple and relatively foolproof for any
> basically-educated-hack to implement, but c) are in fact complex
> (chemically, physically, electronically, conceptually).
>
> Each of my personally-owned sailplanes when purchased had real electrical
> systems in them, including the one I've flown since 1981. Eventually its
> radio died, then its (uncompensated, used only for audio) Ball electric
> vario. Today I use a handheld radio, and one day I hope to remember to
> borrow my wife's Malletec for its audio. Only one person ever has
> criticized my thermal etiquette (his experienced passenger later privately
> told me he disagreed with the criticism), and my fun meter has never felt
> seriously handicapped by the absence of electronic input. My Sage
> continues to work perfectly, accompanied by the usual A/S, (sticky)
> altimeter, and (little-used) whiskey compass. There are at least three
> naked instrument holes in the panel.
>
> Sometimes I feel like a dinosaur.
>
> Regards,
> Bob - a K.I.S.S. fan - Whelan

[Jose Jimenez]

Jeff Runciman schrieb:

> Do I put a mechanical vario or do I save space on the
> panel.

Considering that the Bohli vario is the only truly accurate vario, I
woldn't want to fly without one.

[[email protected]]

On Sep 23, 1:25 pm, Jeff Runciman >
wrote:
> This question was posted earlier but I was hoping for
> a few more responses.
>
> Do I put a mechanical vario or do I save space on the
> panel.
>
> Would love to hear what people have in their panel.
>
> Jeff

Hi Jeff - The ILEC SB-9 is a 2 1/4" self-contained backup
vario with audio, and charges from the normal ship's power.
That's what I have as a backup in my Antares 20E, though this
glider has "more than adequate electrical power" available.

Best Regards, Dave "YO"

[[email protected]]

On Sep 24, 5:54 am, wrote:
> On Sep 23, 1:25 pm, Jeff Runciman >
> wrote:
>
> > This question was posted earlier but I was hoping for
> > a few more responses.
>
> > Do I put a mechanical vario or do I save space on the
> > panel.
>
> > Would love to hear what people have in their panel.
>
> > Jeff
>
> Hi Jeff - The ILEC SB-9 is a 2 1/4" self-contained backup
> vario with audio, and charges from the normal ship's power.
> That's what I have as a backup in my Antares 20E, though this
> glider has "more than adequate electrical power" available.
>
> Best Regards, Dave "YO"

All I have is a Cambridge (I think) mechanical vario that i bought on
RAS. I did make up a TE prob a la dick johnson plans last winter and
it works as well as i could expect for a home made TE probe. Id love
to add audio, anyone know a cheap source? the only other hole in my
panel is sized for the vintage crossfell vario that was in the glider
when i got it. too bad it didnt work to well. it had a diaphragm TE
system and ran on a couple D cells.

[[email protected]]

On Sep 24, 2:53 am, Jose Jimenez <nospam@please> wrote:
>
> Considering that the Bohli vario is the only truly accurate vario, I
> woldn't want to fly without one.

Jose, would you care to expand on that statement?

Re: the original question: My preference is for electric vario as
backup, for audio, reliability, and responsiveness. I use a
Westerboer (sp?) 911, and I have two separate electrical systems in my
glider.

The most likely point of failure in my ship is the TE probe, which
would affect either kind of vario...(my other system is an SN10)

I've never had an electrical failure in over 2400 hours of flying
gliders (so I'm due, obviously). Never had an electric vario fail
inflight. I have flown with a lot of really bad mechanical varios (in
club and rental ships) and hate them.

I find that I thermal on audio, rarely looking at instantaneous lift
value at all - since it is really the change in lift that I care about
in the short term (to center the thermal). So a simple mechanical
would be just a hole-filler.

YMMV, of course.

Kirk
66

[Gary Emerson]

Jeff Runciman wrote:
> This question was posted earlier but I was hoping for
> a few more responses.
>
> Do I put a mechanical vario or do I save space on the
> panel.
>
> Would love to hear what people have in their panel.
>
> Jeff
>
>
>

go for the electric backup that has it's own battery or internal
rechargable battery. No sense being w/o an audio.

[Chip Bearden]

I've always had a backup vario. Some were electric, others mechanical.
Some were completely separate (power, static, TE, pitot), others had a
common point of failure (usually the TE probe and/or electrical bus/
common battery selector switch). I'm not sure there's a perfect answer
although the small, self contained electonic vario with audio/averager
sounds good if you could connect it to a separate TE source.

[On that note, I had a running correspondence with one of the major
vario/flight computer systems last year about offering electronic TE
as a backup option. His contention was that it didn't work as well as
a good TE probe. My point was that if the probe failed (it's happens),
I'd like to have a backup TE vario. We never came to a common
understanding although I think one of the major manufacturers offers
something like this.]

Get something good enough to fly a contest with, not just to limp
home. That way you'll be familiar with it when your primary vario does
fail.

I've had batteries fail with little warning (yes, I have a backup).
The panel-mounted fuse holder came loose at one national contest and
provided intermittant power. One mechanical vario failed suddenly. And
the pressure capsule in my ASI failed at another national contest
which not only gave me no airspeed info but also removed the netto and
speed-to-fly info from my primary vario/flight computer.

If you fly long enough, something will fail. Provide redundancy with
as few common points of failure as possible, then go fly.

Chip Bearden
ASW 24 "JB"
USA

[Martin Gregorie[_1_]]

wrote:
> On Sep 24, 5:54 am, wrote:
>> On Sep 23, 1:25 pm, Jeff Runciman >
>> wrote:
>>
>>> This question was posted earlier but I was hoping for
>>> a few more responses.
>>> Do I put a mechanical vario or do I save space on the
>>> panel.
>>> Would love to hear what people have in their panel.
>>> Jeff
>> Hi Jeff - The ILEC SB-9 is a 2 1/4" self-contained backup
>> vario with audio, and charges from the normal ship's power.
>> That's what I have as a backup in my Antares 20E, though this
>> glider has "more than adequate electrical power" available.
>>
>> Best Regards, Dave "YO"
>
> All I have is a Cambridge (I think) mechanical vario that i bought on
> RAS. I did make up a TE prob a la dick johnson plans last winter and
> it works as well as i could expect for a home made TE probe. Id love
> to add audio, anyone know a cheap source?
>
eBay or other pilots replacing varios?

Seriously, I'd look for a used Borgelt B40 (its now replaced by the B400
but still fully supported by Borgelt) or a Tasman V1000 (used or new).
Both are relatively inexpensive. I've flown with and like both. The B40
has an internal battery for backup. The Tasman is pretty unbreakable
thanks to its LCD display. Both have an averager: you push a button on
the B40 to read average while the Tasman shows instantaneous and average
all the time. Both make nice noises.

> the only other hole in my
> panel is sized for the vintage crossfell vario that was in the glider
> when i got it.
>
How big is a Crossfell?

Both the B40 and Tasman fit a 57mm (2 1/4") hole.


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

[Alastair Lyas]

At 22:30 23 September 2007, Dan G wrote:
>If my primary (electric audio) vario failed it most
>likely be because
>of a general power failure, which would have also have
>left me without
>radio, GPS and logger. If I did want to use a mechanical
>vario, I'd
>have to go 'heads down', which is something I just
>won't do. I'd fly
>home via the seat of my pants.
>
>So, no mechanical vario here.

The words of a K8 flying stroker! Get a life - any
reasonably experienced pilot is perfectly safe with
the odd glance at a mechanical vario!

My advice would be to have at least one back-up vario
either mechanical or electrical. (I fly with Cambridge,
so I have a backup everything, plus a mechanical).
As always buy the best you can afford. A 302 is a pretty
good vario and only fills one 57mm hole, and then you
get a back-up GPS as well. If you are lucky enough
to be able to afford this, then its an option.

[Bill Daniels]

Good point about TE probe failure. I've been thinking about adding a Dick
Johnson midship probe. I'll keep my tail mounted probe as a backup.

About battery failure. I've never known of a failure except in very new
(rare) or very old batteries. I had a conversation with a pilot I saw with
three huge batteries under his arm walking toward his glider.
Q. Why so many?
A. They might fail.
Q. How old are they?
A. I dunno, they came with the glider
Q. How long have you owned the glider?
A. 10 years.

Sealed Lead Acid rechargables are really only reliable for three years
whether on the shelf or in use. I start with a fresh one every two years.
I also go through the wiring at least twice a season. So far, no failures.

Bill D


"Chip Bearden" > wrote in message
ups.com...
> I've always had a backup vario. Some were electric, others mechanical.
> Some were completely separate (power, static, TE, pitot), others had a
> common point of failure (usually the TE probe and/or electrical bus/
> common battery selector switch). I'm not sure there's a perfect answer
> although the small, self contained electonic vario with audio/averager
> sounds good if you could connect it to a separate TE source.
>
> [On that note, I had a running correspondence with one of the major
> vario/flight computer systems last year about offering electronic TE
> as a backup option. His contention was that it didn't work as well as
> a good TE probe. My point was that if the probe failed (it's happens),
> I'd like to have a backup TE vario. We never came to a common
> understanding although I think one of the major manufacturers offers
> something like this.]
>
> Get something good enough to fly a contest with, not just to limp
> home. That way you'll be familiar with it when your primary vario does
> fail.
>
> I've had batteries fail with little warning (yes, I have a backup).
> The panel-mounted fuse holder came loose at one national contest and
> provided intermittant power. One mechanical vario failed suddenly. And
> the pressure capsule in my ASI failed at another national contest
> which not only gave me no airspeed info but also removed the netto and
> speed-to-fly info from my primary vario/flight computer.
>
> If you fly long enough, something will fail. Provide redundancy with
> as few common points of failure as possible, then go fly.
>
> Chip Bearden
> ASW 24 "JB"
> USA
>

[[email protected]]

On Sep 24, 10:29 am, Martin Gregorie >
wrote:
> wrote:
> > On Sep 24, 5:54 am, wrote:
> >> On Sep 23, 1:25 pm, Jeff Runciman >
> >> wrote:
>
> >>> This question was posted earlier but I was hoping for
> >>> a few more responses.
> >>> Do I put a mechanical vario or do I save space on the
> >>> panel.
> >>> Would love to hear what people have in their panel.
> >>> Jeff
> >> Hi Jeff - The ILEC SB-9 is a 2 1/4" self-contained backup
> >> vario with audio, and charges from the normal ship's power.
> >> That's what I have as a backup in my Antares 20E, though this
> >> glider has "more than adequate electrical power" available.
>
> >> Best Regards, Dave "YO"
>
> > All I have is a Cambridge (I think) mechanical vario that i bought on
> > RAS. I did make up a TE prob a la dick johnson plans last winter and
> > it works as well as i could expect for a home made TE probe. Id love
> > to add audio, anyone know a cheap source?
>
> >
> eBay or other pilots replacing varios?
>
> Seriously, I'd look for a used Borgelt B40 (its now replaced by the B400
> but still fully supported by Borgelt) or a Tasman V1000 (used or new).
> Both are relatively inexpensive. I've flown with and like both. The B40
> has an internal battery for backup. The Tasman is pretty unbreakable
> thanks to its LCD display. Both have an averager: you push a button on
> the B40 to read average while the Tasman shows instantaneous and average
> all the time. Both make nice noises.
>
> > the only other hole in my
> > panel is sized for the vintage crossfell vario that was in the glider
> > when i got it.
>
> >
> How big is a Crossfell?
>
> Both the B40 and Tasman fit a 57mm (2 1/4") hole.
>
> --
> martin@ | Martin Gregorie
> gregorie. | Essex, UK
> org |- Hide quoted text -
>
> - Show quoted text -

the crosfell is smaller than a 2 1/4 standard instrument, i could
probably cut the panel out to a bigger size though. thanks for the
tip on the B40 and Tasman, ill check them out. would have to add
another wire from my fancy pantsy 12 V battery electrical system.

[Dan G]

On Sep 24, 4:19 pm, Owain Walters
> wrote:
> As for the 'heads down' comment, I cant see why having
> a mechanical vario would force your head down the entire
> time. Surely a glance at the variometer every now and
> again doesnt make your lookout become dangerous?

No, it doesn't. I was trying to imagine centering a thermal with only
a mechanical, which would probably demand more head-down time.

I admit though I have little experience of complex vario/flight
computers - I'm not a comp pilot and think vario technology peaked
with the B40 :-).

Must agree with Kirk on the quality of mechanical varios - I've not
flown a glider where the mechanical agrees with the electric! I
suspect that on a lot of gliders the mechanical, being the back-up,
doesn't get the TLC it needs to remain accurate (I'm sure they were
when new).


Dan

[John Smith]

> Must agree with Kirk on the quality of mechanical varios - I've not
> flown a glider where the mechanical agrees with the electric! I
> suspect that on a lot of gliders the mechanical, being the back-up,
> doesn't get the TLC it needs to remain accurate (I'm sure they were
> when new).

It may have been poor installation. If you run a pressure driven vario
on the same TE line as a flow driven, then you may get some funny read outs.

[Bruce]

Master Martin

The three Tasman V1000 varios in our club have to be the most reliable
instruments we have. No moving parts, low power drain and they keep working down
to ludicrous voltages. You did not mention it but the LX is also worth considering.

In the club ships the mechanical varios get so battered they become less than
helpful. You can re-center them and calibrate them, but mechanical things
experience variation in manufacture and wear.

I keep a Winter mechanical vario in my personal aircraft partly because I have
had complete electrical failure in flight - and it is reassuring to have
something that pretty much works as long as there is airflow. But if I am honest
with myself, it is mainly because I hate holes in panels...

When I bought the aircraft it had a Westerboer WV5KB vario that did not co-exist
with the mechanical vario. Previous owner had installed restrictors and filters
and any number of kludges, that effectively meant that you had two instruments
that were pretty useless at all times. Removed the old electrical vario - it
came from the days when having "transistors" was an advertising point and was
wildly inaccurate.

A simple split of the TE line about 1m from the instrument panel (under the
seat) and the Tasman and Winter co-exist happily. Simple test using SeeYou to
analyse after noting the averages show that the Tasman is remarkably accurate.
Strangely the Tasman is often showing a lot more on the instantaneous readout
than the Winter. Presumably this is because of some degree of mechanical damping.

There are times when the mechanical sweep of the Winter can tell you things that
the electronic vario can't - we are very good at assimilating and assessing the
implications of movement. Conversely, I seldom use it because the audio is more
use centring, and the averager display tells me much more about whether to
persist. Once you go over to the dark side and start using the information the
electronic vario can provide to a flight computer or PDA there is no going back.

So - a modern solid state electronic vario is the way to go. If you need backup,
get one with a separate or internal battery. There is little chance that a
mechanical vario will be an improvement on that. Now if I could just convince
the wife that I really NEED another gadget, maybe a LX160, or a B400 would be
nice, and one o the club ships can have the Winter.

Bruce

Martin Gregorie wrote:
> wrote:
>> On Sep 24, 5:54 am, wrote:
>>> On Sep 23, 1:25 pm, Jeff Runciman >
>>> wrote:
>>>
>>>> This question was posted earlier but I was hoping for
>>>> a few more responses.
>>>> Do I put a mechanical vario or do I save space on the
>>>> panel.
>>>> Would love to hear what people have in their panel.
>>>> Jeff
>>> Hi Jeff - The ILEC SB-9 is a 2 1/4" self-contained backup
>>> vario with audio, and charges from the normal ship's power.
>>> That's what I have as a backup in my Antares 20E, though this
>>> glider has "more than adequate electrical power" available.
>>>
>>> Best Regards, Dave "YO"
>>
>> All I have is a Cambridge (I think) mechanical vario that i bought on
>> RAS. I did make up a TE prob a la dick johnson plans last winter and
>> it works as well as i could expect for a home made TE probe. Id love
>> to add audio, anyone know a cheap source?
> >
> eBay or other pilots replacing varios?
>
> Seriously, I'd look for a used Borgelt B40 (its now replaced by the B400
> but still fully supported by Borgelt) or a Tasman V1000 (used or new).
> Both are relatively inexpensive. I've flown with and like both. The B40
> has an internal battery for backup. The Tasman is pretty unbreakable
> thanks to its LCD display. Both have an averager: you push a button on
> the B40 to read average while the Tasman shows instantaneous and average
> all the time. Both make nice noises.
>
>> the only other hole in my
>> panel is sized for the vintage crossfell vario that was in the glider
>> when i got it.
> >
> How big is a Crossfell?
>
> Both the B40 and Tasman fit a 57mm (2 1/4") hole.
>
>

[Eric Greenwell]

Owain Walters wrote:
> I would always have a mechanical vario in my glider.
> I use the electric (audio) as an indicator that I should
> take a look at the far more accurate mechanical vario.

So, how do you know it is "far more accurate"? The mechanical varios I'm
familiar with change their calibration with altitude, but perhaps yours
doesn't?

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[Brian[_1_]]

<snip>
> Another way of asking the question could be "who has ever had their
> primary vario fail?"
>
<snip>

I have had the general Power failure version.

I have also had the Bubble Bee impaled on the pitot failure. Since my
primary vario is internally compensated this gave it some very strange
readings. Fortunatly my B40 is compensated by a TE Probe.

Brian
CFIIG/ASEL
HP16T N16VP

[Brian[_1_]]

ILEC's are a bit more expensive, But I actually liked the Audio on it
better than the B40 I currently have.
The ILEC (SB-7) was my primary vario in my 1-26 and I loved it.

Brian
HP16T N16VP

[[email protected]]

On Sep 24, 9:18 am, wrote:
> On Sep 24, 5:54 am, wrote:
> > Hi Jeff - The ILEC SB-9 is a 2 1/4" self-contained backup
> > vario with audio, and charges from the normal ship's power.
> > That's what I have as a backup in my Antares 20E, though this
> > glider has "more than adequate electrical power" available.
>
> > Best Regards, Dave "YO"
>
> All I have is a Cambridge (I think) mechanical vario that i bought on
> RAS. I did make up a TE prob a la dick johnson plans last winter and
> it works as well as i could expect for a home made TE probe. Id love
> to add audio, anyone know a cheap source? the only other hole in my
> panel is sized for the vintage crossfell vario that was in the glider
> when i got it. too bad it didnt work to well. it had a diaphragm TE
> system and ran on a couple D cells.

Cambridge never made a mechanical vario, you are confused.

A homemade TE probe works on a Cherokee because, well, it
cannot really convert retained energy (ie, cannot do a high-speed
pass). On anything resembling a modern glider (say, a Blanik),
it is much less likely to work acceptably.

The vintage Crossfell should be fine for the Cherokee, even without
the TE diaphragm gizmo or proper TE probe...

Nothing against the Cherokee or other vintage equipment, but
its instrumentation needs are a bit different from what most
readers here fly...

Hope that helps clear up any confusion,
Best Regards, Dave

[[email protected]]

On Sep 24, 9:11 pm, wrote:
> On Sep 24, 9:18 am, wrote:
>
> > On Sep 24, 5:54 am, wrote:
> > > Hi Jeff - The ILEC SB-9 is a 2 1/4" self-contained backup
> > > vario with audio, and charges from the normal ship's power.
> > > That's what I have as a backup in my Antares 20E, though this
> > > glider has "more than adequate electrical power" available.
>
> > > Best Regards, Dave "YO"
>
> > All I have is a Cambridge (I think) mechanical vario that i bought on
> > RAS. I did make up a TE prob a la dick johnson plans last winter and
> > it works as well as i could expect for a home made TE probe. Id love
> > to add audio, anyone know a cheap source? the only other hole in my
> > panel is sized for the vintage crossfell vario that was in the glider
> > when i got it. too bad it didnt work to well. it had a diaphragm TE
> > system and ran on a couple D cells.
>
> Cambridge never made a mechanical vario, you are confused.
>
> A homemade TE probe works on a Cherokee because, well, it
> cannot really convert retained energy (ie, cannot do a high-speed
> pass). On anything resembling a modern glider (say, a Blanik),
> it is much less likely to work acceptably.
>
> The vintage Crossfell should be fine for the Cherokee, even without
> the TE diaphragm gizmo or proper TE probe...
>
> Nothing against the Cherokee or other vintage equipment, but
> its instrumentation needs are a bit different from what most
> readers here fly...
>
> Hope that helps clear up any confusion,
> Best Regards, Dave

I didnt know that there was any confusion. The more I thought about
it the more I realized that I have a Winter not a Cambridge. The
Crossfell did work OK but the scaling was off, like it never ever
showed more than 1 m/s and it would show down when I was going up.
Both of these issues may have been due to not enough voltage and
reversed polarity.

[kirk.stant]

On Sep 25, 3:01 am, Owain Walters
> wrote:
> Because while the electric is flailing around the mechnical
> gives indications that match what is happening with
> a timed average.

So what you are saying is that you use your mechanical as an
averager. Which is fine, but doesn't say much for the accuracy of the
vario!

> Whilst I agree electric varios are much better than
> they used to be (I fly with a LX7000) I have always,
> and still do, find that my mechanical gives a much
> more 'real world' reading than an electric.

Which leads to an interesting point - it isn't so much the actual
reading on the vario that is important, as the ease of using the data
presented to climb more efficiently. So the whole "accuracy" argument
is a bit ridiculous. If it is really sensitive, it overreacts to
gusts. If it is highly damped, it's an averager. That's why I want
the audio, to let my brain (and butt) figure out the gusts from the
surges and center accordingly. Tough while staring at a needle on a
mechanical that hasn't been looked at much before, after the needle on
the ubervario MK 69 falls off...

> To be fair, the altitude thing is rarely an issue where
> I fly...!
> Owain

I hear you! Nothing like setting off XC at 2000' agl to make you
appreciate a good vario.

Cheers,
Kirk
66

[toad]

On Sep 25, 10:51 am, "kirk.stant" > wrote:
....
> Which leads to an interesting point - it isn't so much the actual
> reading on the vario that is important, as the ease of using the data
> presented to climb more efficiently. So the whole "accuracy" argument
> is a bit ridiculous. If it is really sensitive, it overreacts to
> gusts. If it is highly damped, it's an averager. That's why I want
> the audio, to let my brain (and butt) figure out the gusts from the
> surges and center accordingly. Tough while staring at a needle on a
> mechanical that hasn't been looked at much before, after the needle on
> the ubervario MK 69 falls off...
....
> Cheers,
> Kirk
> 66

One thing that bugs me about my mechanical (a winter) is that it
always over states the lift, which is important when deciding to take
a thermal or not. The damn thing generally tells me 6 knots, when it
is only 3-4 steady on the averager ! I need the re-paint the face
plate :-)

Todd Smith
3S

[[email protected]]

> I hear you! Nothing like setting off XC at 2000' agl to make you
> appreciate a good vario.

hmmm maybe thats what my problem has been this year ;)

[Eric Greenwell]

Owain Walters wrote:
> Because while the electric is flailing around the mechnical
> gives indications that match what is happening with
> a timed average.

If your electric is "flailing around", that suggests a problem in the
pneumatic connections or the vario settings. For example, I set my
Cambridge 302 for a relatively fast audio response (~ 1.3 second
response), but a slower needle response (1.7 second response - similar
to a good mechanical vario). The averager (~ 20-30 second response)
gives a climb rate in excellent agreement to the actual climb rate,
though this can be checked easily only in very smooth thermals.

These three different responses give me a feel for detecting, centering,
and ultimately deciding when to leave a thermal.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[Cliff Hilty[_2_]]

I agree with Kirk as far as the 'useful' info is concerened.
I have a Sage mechanical (thanks kirk) as the mechanical
backup to my SN10. I find that the Mechanical gives
me a good indication of whats happening outside with
air as it is compensated and gust filtered very well,
and the SN10 gives me a very fast response and allows
me to center quicker and stay there. In other words
when I hear an audio response to lift while cruising
I slow down and glance at the sage and determine whether
or not it is worth making a turn or moving on. The
Sage gives me a better avgerage of what I just flew
into than the SN10. The SN10 gives me a instant responce
that is to short of a time frame to tell if it is
a gust or continued lift. I would like to have a 9volt
audio back up connected to the sage in case of power
failure, but not enough room in the panel :( or is
there?


At 14:54 25 September 2007, Kirk.Stant wrote:

Which leads to an interesting point - it isn't so much
the actual
reading on the vario that is important, as the ease
of using the datapresented to climb more efficiently.
So the hole 'accuracy' argument is a bit ridiculous.
If it is really sensitive, it overreacts to gusts.
If it is highly damped, it's an averager. That's why
I want the audio, to let my brain (and butt) figure
out the gusts from the surges and center accordingly.
Tough while staring at a needle on a mechanical that
hasn't been looked at much before, after the needle
on the ubervario MK 69 falls off...

[HL Falbaum]

Once upon a time, there was such a thing----an electric audio attachment for
a pneumatic/mechanical vario. Or perhaps it was just plumbed in the
pneumatic lines. Adjustable for volume and threshold. It was a little black
box that didn't need to be in the panel at all. Perhaps you can find a used
one somewhere.
--
Hartley Falbaum

"Cliff Hilty" > wrote in message
...
>I agree with Kirk as far as the 'useful' info is concerened.
> I have a Sage mechanical (thanks kirk) as the mechanical
> backup to my SN10. I find that the Mechanical gives
> me a good indication of whats happening outside with
> air as it is compensated and gust filtered very well,
> and the SN10 gives me a very fast response and allows
> me to center quicker and stay there. In other words
> when I hear an audio response to lift while cruising
> I slow down and glance at the sage and determine whether
> or not it is worth making a turn or moving on. The
> Sage gives me a better avgerage of what I just flew
> into than the SN10. The SN10 gives me a instant responce
> that is to short of a time frame to tell if it is
> a gust or continued lift. I would like to have a 9volt
> audio back up connected to the sage in case of power
> failure, but not enough room in the panel :( or is
> there?
>
>
> At 14:54 25 September 2007, Kirk.Stant wrote:
>
> Which leads to an interesting point - it isn't so much
> the actual
> reading on the vario that is important, as the ease
> of using the datapresented to climb more efficiently.
> So the hole 'accuracy' argument is a bit ridiculous.
> If it is really sensitive, it overreacts to gusts.
> If it is highly damped, it's an averager. That's why
> I want the audio, to let my brain (and butt) figure
> out the gusts from the surges and center accordingly.
> Tough while staring at a needle on a mechanical that
> hasn't been looked at much before, after the needle
> on the ubervario MK 69 falls off...
>
>
>
>

[Doug Hoffman]

> The Crossfell did work OK but the scaling was off, like it
> never ever
> showed more than 1 m/s

The Crossfell in my RS-15 (glider now sold) gave 32 years
of reliable service. The Crossfell was retired in perfect
working condition. There was a rotary switch
that changed the scale to 3x or 5x, I forget exactly which.
Yours may have been set or stuck in expanded scale.

Btw, mine read in feet per second. My mechanical backup was in
meters per second.
Meanwhile, over the radio everyone was talking about how many
knots of lift they were in. ;-)

> and it would show down when I was going up.

Yeah, that's an indication that something was amiss.

--
Regards,
Doug


--
Posted via a free Usenet account from http://www.teranews.com

[Brian[_1_]]

>
> One thing that bugs me about my mechanical (a winter) is that it
> always over states the lift, which is important when deciding to take
> a thermal or not. The damn thing generally tells me 6 knots, when it
> is only 3-4 steady on the averager ! I need the re-paint the face
> plate :-)
>

Perhaps you have too large of a capacity bottle on it.

Putting a smaller capacity on it will lower the readings on you
Winter.

Brian
CFIIG/ASEL

[[email protected]]

On Sep 25, 1:12 pm, "HL Falbaum" > wrote:
> Once upon a time, there was such a thing----an electric audio attachment for
> a pneumatic/mechanical vario. Or perhaps it was just plumbed in the
> pneumatic lines. Adjustable for volume and threshold. It was a little black
> box that didn't need to be in the panel at all. Perhaps you can find a used
> one somewhere.

thats what i would really like.

[Bob Kuykendall]

On Sep 25, 4:51 pm, wrote:
> thats what i would really like.

I think what you're looking for is a Piep audio. There were a lot of
them about in the 1960s and 1970s. Very simple and reliable. Two knobs
(volume and threshold), two hose connectors (static and capacity), and
a plug for +12DCV and ground. They have fairly low restriction, so you
can plub it in series with a mechanical vario without problem. They
seem to like a one-pint flask, but they're not particularly picky. I
had one for ten years and really liked it.

I bet if you ask around among the old-timers in your area you'll find
somebody with one in the bottom of a box of junk. It'll probably still
have the Graham Thompson sticker on it.

Thanks, Bob K.

[Wayne Paul]

> wrote in message
ps.com...
> On Sep 25, 1:12 pm, "HL Falbaum" > wrote:
>> Once upon a time, there was such a thing----an electric audio attachment
>> for
>> a pneumatic/mechanical vario. Or perhaps it was just plumbed in the
>> pneumatic lines. Adjustable for volume and threshold. It was a little
>> black
>> box that didn't need to be in the panel at all. Perhaps you can find a
>> used
>> one somewhere.
>
> thats what i would really like.
>

Surely some one out there has an old Piep 2 Audio Vario that they are
willing to part with. (Or, maybe the newer Winter model.)

I gave away my last one a couple years ago.

Wayne
http://www.soaridaho.com/

[Chip Bearden]

On Sep 25, 8:16 pm, Bob Kuykendall > wrote:
> On Sep 25, 4:51 pm, wrote:
>
> > thats what i would really like.
>
> I think what you're looking for is a Piep audio. There were a lot of
> them about in the 1960s and 1970s. Very simple and reliable. Two knobs
> (volume and threshold), two hose connectors (static and capacity), and
> a plug for +12DCV and ground. They have fairly low restriction, so you
> can plub it in series with a mechanical vario without problem. They
> seem to like a one-pint flask, but they're not particularly picky. I
> had one for ten years and really liked it.
>
> I bet if you ask around among the old-timers in your area you'll find
> somebody with one in the bottom of a box of junk. It'll probably still
> have the Graham Thompson sticker on it.
>
> Thanks, Bob K.

Yes, the Piep was a nice gadget. I also flew with one for many years--
it was my first audio vario--and liked it. When electric varios became
ubiquitous in the U.S. (mostly Cambridge in those days), we sold it.
If you can find a working one, it's a cheap, simple way to add audio
to most mechanical varios. IIRC, the current drain was very low, too.
This was back in the days when we all had Bayside BEI-990 radios and a
set of batteries (Everready 560?) needed charging only a few times a
season. That sounds crazy as I type this. Does anyone else remember if
this was true? :)

Chip Bearden
ASW 24 "JB"
USA

[Tim Mara]

Piep audio was made and sold through Winter in Germany but that was some
time ago.....I actually bought the very last ones they had probably 5-6
years ago...maybe longer....and had some repaired by them about the same
time ...but they said then no more parts existed for these..Another Winter
first instrument that faded from view but was really very interesting at the
time was the Stollfarhtgaber, actually the first Speed-to-fly
variometer/airspeed indicator all-in one....all done mechanically and
pneumatically with no need for volts of any kind...these too and parts for
them are no longer available
Funny as we seem to advance towards more sophisticated do-everything
electronic gadgets how we look back on what worked then and would still work
today with a lot less time setting up, reading manuals and sorting things
out on RAS..... I never remember having to have all these conversations and
technical workshops on how to wind or smoke a barograph and never once had
the software or PC link or lack of a serial port miss a turnpoint done on a
Kodak.....:o)
All in the way of technology...and to many a giant leap sideways :o)
So while many might claim an electronic vario is a must for a back-up I
still personally prefer a mechanical running on a probe...it to me also
shows to me what I feel in the flight more naturally than any electronic
one.
tim

Please visit the Wings & Wheels website at www.wingsandwheels.com


"Bob Kuykendall" > wrote in message
ups.com...
> On Sep 25, 4:51 pm, wrote:
>> thats what i would really like.
>
> I think what you're looking for is a Piep audio. There were a lot of
> them about in the 1960s and 1970s. Very simple and reliable. Two knobs
> (volume and threshold), two hose connectors (static and capacity), and
> a plug for +12DCV and ground. They have fairly low restriction, so you
> can plub it in series with a mechanical vario without problem. They
> seem to like a one-pint flask, but they're not particularly picky. I
> had one for ten years and really liked it.
>
> I bet if you ask around among the old-timers in your area you'll find
> somebody with one in the bottom of a box of junk. It'll probably still
> have the Graham Thompson sticker on it.
>
> Thanks, Bob K.
>

[Chip Bearden]

I remember the Solfahrtgeber, too, though I never flew with one. I
guess the biggest drawback was that because everything was mechanical,
they were calibrated for one type of sailplane. Buy a better glider
and you needed a new speed-to-fly vario. Otherwise known as planned
obsolescence. :)

Speaking of simplicity, I flew for a long time with a pure netto
vario. In still air, the needle pointed to zero. You needed at least a
couple of knots "up" to achieve zero sink, which is something that
quickly became automatic. The nice thing was that when you flew into
sink, the needle of the vario immediately pointed to the proper speed
to fly on the speed ring. There was no "chasing the needle" caused by
the sink rate of the glider increasing as you speeded up and the
needle moving a little more causing you to have to speed up a little
more until everything stabilized...by which time you were long past
the sink. In some respects the "relative netto" I use today on my
fancy vario/flight computer with the push/pull bars requires a little
more attention. Progress, progress.

Tim, I absolutely agree with you that the electronic/GPS revolution
that's taken over soaring is not all for the better. New pilots
struggle to understand how to set up all the gadgets they [think they]
need. But even the experienced hands have troubles. On almost any day
at any big contest you will find at least one pilot (often more) who
is frustrated because one of his fancy/expensive instruments isn't
working right, or at all. Years ago, I was annoyed when we went to
clock cameras here in the U.S. and I had to buy two new cameras at
$100 each, in particular when I never actually used the clock feature.
How quaint were my objections then! Now many pilots carry two flight
computers. And while that's still optional, everyone has finally
admitted that you need two GPS loggers, although thankfully a close
reading of the U.S. rules reveals you can get by with a recording
handheld GPS receiver for your backup at a cost of only a few hundred
dollars...on top of the IGC-approved primary logger. I enjoy being
relieved from the chores of navigating with charts and knowing
precisely how far out I am on final glide but I fought against GPS in
the cockpit in part because navigation used to be a skill we measured
in competition.

Fortunately I'm computer savvy, work in the IT industry, and so can
generally get the latest hardware and software to do what it's
supposed to do most of the time. But I do wonder how much more
difficult it has become for someone coming into our sport to afford
all this technology, to learn how to configure it and use it, and to
become familiar with our complex competition rules. The latest gadgets
make it easier for experienced hands to go faster with less attention
devoted to mundane chores but I think they also sometimes raise the
bar for newer pilots in several ways. Not the direction we want to go
in our shrinking sport. Just my opinion.

Chip Bearden
ASW 24 "JB"
USA

[toad]

Chip,

I was a new guy in soaring about 7 years ago and as I was working on
my Silver badge, got a lesson in how to smoke a windup barograph and
all that. I bought a used thermal electric model that required no
screwing around, all I had to do was put it in the glider. I then
tried to do my Silver distance with a camera, the rigmarole was
ridiculous. I ordered a Colibri immediately after that and badge
flights have been simple (except for the flying) ever since.

I agree that electronics require a certain amount of screwing around,
but so cameras and barographs. Most of the computer mess only has
to be done once, then the per-flight work is simple.

Todd Smith
3S

[Eric Greenwell]

Chip Bearden wrote:

> Speaking of simplicity, I flew for a long time with a pure netto
> vario. In still air, the needle pointed to zero. You needed at least a
> couple of knots "up" to achieve zero sink, which is something that
> quickly became automatic. The nice thing was that when you flew into
> sink, the needle of the vario immediately pointed to the proper speed
> to fly on the speed ring.

You must have had a pretty good unit, because my unit always pointed to
the speed I should have been flying 10-15 seconds before I got to to
that speed! By the time I got there, the air was different, and it was
telling me to fly a different speed. OK, with the Ka-6e, the speed range
was small enough, I was able to stay close, but with faster gliders, I
can't really fly "the speed to fly" because it's changing faster than I
can change speed, so I do what I saw most of the hot shots doing in
contests - flying a steady speed and picking a good route through the air.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[Bill Daniels]

In addition to my old reliable B40, I have a newly old B50. As I'm cruising
along the B50's audio will switch to slow yodel and two blue LED's will
light up indicating the need to slow down "a lot". It's usually not clear
to me why I should slow down but I've learned to trust it. After I enter
the zoom I usually feel a kick in the pants as I enter a strong thermal. It
seems to know a thermal is coming well before I do.

Mike, HOW DOES IT DO THAT?

Bill Daniels

[[email protected]]

On Sep 26, 10:53 pm, "Bill Daniels" <bildan@comcast-dot-net> wrote:
> In addition to my old reliable B40, I have a newly old B50. As I'm cruising
> along the B50's audio will switch to slow yodel and two blue LED's will
> light up indicating the need to slow down "a lot". It's usually not clear
> to me why I should slow down but I've learned to trust it. After I enter
> the zoom I usually feel a kick in the pants as I enter a strong thermal. It
> seems to know a thermal is coming well before I do.
>
> Mike, HOW DOES IT DO THAT?
>
> Bill Daniels

dang, I REALLY need to get one of those!

[Chip Bearden]

On Sep 26, 9:41 pm, Eric Greenwell > wrote:
> You must have had a pretty good unit, because my unit always pointed to
> the speed I should have been flying 10-15 seconds before I got to to
> that speed! By the time I got there, the air was different, and it was
> telling me to fly a different speed. OK, with the Ka-6e, the speed range
> was small enough, I was able to stay close, but with faster gliders, I
> can't really fly "the speed to fly" because it's changing faster than I
> can change speed, so I do what I saw most of the hot shots doing in
> contests - flying a steady speed and picking a good route through the air.

I followed the needle a lot more then than now. I'm not sure whether
the dramatic zoomies and pushovers made sense but they were fun. :)

In any case, I like having a number in front of me that says what I
should be doing. It's like the speed to fly number in GNII: If you set
the MacCready value for, say 4 kts., then the normal cruise speed
shows up as, say, 80 kts. But at least in the software version I'm
flying, that speed number remains constant no matter what the airmass
is doing. If I'm flying through monster sink, I would like to know
that my new "ideal" speed is now 100 kts. even if I choose not to
chase it. That's what the netto speed ring did. What I don't like to
do is follow a needle (or push/pull bars) blindly, not knowing whether
I'm 6 kts. or 26 kts. too slow or fast. With my set up, the closest I
can come to that is to adjust the allowable speed deviation before the
flight computer starts beeping at me but I still don't know how far
away from the "ideal" speed I am. Is that instant "ideal" speed
available on other flight computers?

Chip Bearden
ASW 24 "JB"
USA

[Eric Greenwell]

wrote:
> On Sep 26, 10:53 pm, "Bill Daniels" <bildan@comcast-dot-net> wrote:
>> In addition to my old reliable B40, I have a newly old B50. As I'm cruising
>> along the B50's audio will switch to slow yodel and two blue LED's will
>> light up indicating the need to slow down "a lot". It's usually not clear
>> to me why I should slow down but I've learned to trust it. After I enter
>> the zoom I usually feel a kick in the pants as I enter a strong thermal. It
>> seems to know a thermal is coming well before I do.
>>
>> Mike, HOW DOES IT DO THAT?
>>
>> Bill Daniels
>
> dang, I REALLY need to get one of those!

Save your money - you are flying a glider that is already slowed down!
Seriously - Bill might be cruising 40 knots over his thermalling speed,
while you are maybe cruising 10 knots above your thermalling speed. Set
the money aside for another glider, or use it to go to contest or
soaring camp.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[[email protected]]

On Sep 27, 9:10 am, Eric Greenwell > wrote:
> wrote:
> > On Sep 26, 10:53 pm, "Bill Daniels" <bildan@comcast-dot-net> wrote:
> >> In addition to my old reliable B40, I have a newly old B50. As I'm cruising
> >> along the B50's audio will switch to slow yodel and two blue LED's will
> >> light up indicating the need to slow down "a lot". It's usually not clear
> >> to me why I should slow down but I've learned to trust it. After I enter
> >> the zoom I usually feel a kick in the pants as I enter a strong thermal. It
> >> seems to know a thermal is coming well before I do.
>
> >> Mike, HOW DOES IT DO THAT?
>
> >> Bill Daniels
>
> > dang, I REALLY need to get one of those!
>
> Save your money - you are flying a glider that is already slowed down!
> Seriously - Bill might be cruising 40 knots over his thermalling speed,
> while you are maybe cruising 10 knots above your thermalling speed. Set
> the money aside for another glider, or use it to go to contest or
> soaring camp.
>
> --
> Eric Greenwell - Washington State, USA
> * Change "netto" to "net" to email me directly
> * "Transponders in Sailplanes"http://tinyurl.com/y739x4
> * "A Guide to Self-launching Sailplane Operation" atwww.motorglider.org

fair enough eric. a guy can dream though.

this discussion reminds me of this story by Jim Foreman. classic.
http://www.jimforeman.com/Stories/varios.htm

[[email protected]]

On Sep 27, 8:29 am, wrote:
> On Sep 27, 9:10 am, Eric Greenwell > wrote:
>
>
>
>
>
> > wrote:
> > > On Sep 26, 10:53 pm, "Bill Daniels" <bildan@comcast-dot-net> wrote:
> > >> In addition to my old reliable B40, I have a newly old B50. As I'm cruising
> > >> along the B50's audio will switch to slow yodel and two blue LED's will
> > >> light up indicating the need to slow down "a lot". It's usually not clear
> > >> to me why I should slow down but I've learned to trust it. After I enter
> > >> the zoom I usually feel a kick in the pants as I enter a strong thermal. It
> > >> seems to know a thermal is coming well before I do.
>
> > >> Mike, HOW DOES IT DO THAT?
>
> > >> Bill Daniels
>
> > > dang, I REALLY need to get one of those!
>
> > Save your money - you are flying a glider that is already slowed down!
> > Seriously - Bill might be cruising 40 knots over his thermalling speed,
> > while you are maybe cruising 10 knots above your thermalling speed. Set
> > the money aside for another glider, or use it to go to contest or
> > soaring camp.
>
> > --
> > Eric Greenwell - Washington State, USA
> > * Change "netto" to "net" to email me directly
> > * "Transponders in Sailplanes"http://tinyurl.com/y739x4
> > * "A Guide to Self-launching Sailplane Operation" atwww.motorglider.org
>
> fair enough eric. a guy can dream though.
>
> this discussion reminds me of this story by Jim Foreman. classic.http://www.jimforeman.com/Stories/varios.htm- Hide quoted text -
>
> - Show quoted text -

Or just drag that Cherokee out West. The 1-26ers get in some amazing
flights out here!
Back to the subject.... and this may be a bit of a 'noob' question.
Is there an instrument that will indicate the optimum speed to fly to
get through large areas of HUGE sink, also taking into account winds?
I have a very basic 302A FR, and an iPAQ with XCSoar.
Hints?
Jim "Flies with Sheep"
N16UF

[Bob Whelan[_2_]]

Chip Bearden wrote:
> (snip)
>
> Speaking of simplicity, I flew for a long time with a pure netto
> vario. In still air, the needle pointed to zero. You needed at least a
> couple of knots "up" to achieve zero sink, which is something that
> quickly became automatic. The nice thing was that when you flew into
> sink, the needle of the vario immediately pointed to the proper speed
> to fly on the speed ring. There was no "chasing the needle" caused by
> the sink rate of the glider increasing as you speeded up and the
> needle moving a little more causing you to have to speed up a little
> more until everything stabilized...by which time you were long past
> the sink. In some respects the "relative netto" I use today on my
> fancy vario/flight computer with the push/pull bars requires a little
> more attention. Progress, progress.

My primary vario for 26 years was/is a Sage connected to a Schuemann B
box, which does exactly what Chip describes. Everyone in this
silly/wonderful sport gets to define their own "ideal setup"; this is
mine. IMHO one of the Great Mysteries of Life is why so few choose this
particular set-up. Even Reichmann dissed it in favor of something
genuinely more arcane in my view. Imagine you're a hawk, with a hawk's
sensors, skill set and hunger. Seems to me the One Thing you'd want to
know is how fast you *could* be climbing should you decide to, AND what
your...seems to me the TWO Things you'd want to know are how fast you
*could* be climbing should you decide to, AND what your speed to fly
should be should you choose not to climb. Compensated netto immediately
shows you both at a single glance. (Mirabile dictu!!!)


> (More snips...)
> Fortunately I'm computer savvy, work in the IT industry, and so can
> generally get the latest hardware and software to do what it's
> supposed to do most of the time. But I do wonder how much more
> difficult it has become for someone coming into our sport to afford
> all this technology, to learn how to configure it and use it, and to
> become familiar with our complex competition rules. The latest gadgets
> make it easier for experienced hands to go faster with less attention
> devoted to mundane chores but I think they also sometimes raise the
> bar for newer pilots in several ways. Not the direction we want to go
> in our shrinking sport. Just my opinion.

Chip touches above ("but I think they also sometimes raise the bar for
newer pilots in several ways. Not the direction we want to go
in our shrinking sport.") on an aspect of soaring I suspect has more
than just a hint of truth to it. Like Chip, I'm reasonably computer
savvy, comfortable with working with hardware and software, etc., but
the soaring pilot in me has essentially zero desire to get onboard this
particular technological rat-race. Give me some basic information in an
easily-absorbed and useful presentation, and no further punching of my
soaring ticket need be done. Officially, I have 2/3 of my Silver Badge
(both achieved in a 1-26), while my mind notes the remaining legs
claimed (in a minimally-outfitted, dry, 1st-generation 15-meter ship).
I still figure if I get outflown in that ship, it's because of better
pilotage, not better instrumentation or a better ship. Regrettably,
with the passage of time, it seems to me that fewer and fewer newbies
and XC-wannabes lend much credence to my claims.

Personally, I think the Gospel of Simplicity ought to be preached more,
because so much of soaring does not REQUIRE the latest in bells and
whistles be present in order for fledglings to begin spreading their
wings in personally gratifying and safe ways. Flight (in any form)
costs more than remaining groundbound. Soaring flight as a niche
certainly isn't cheap (in time or money or mental effort required), and
any barriers (real or imagined) to achieving it are precisely that:
barriers. I don't think soaring participants should be promoting Mark
CXXIV widgets as a universal good, or worse, as necessary, to everyone
getting into the sport. Sell the sport first...the widgets will tag
along in their own good time as newbies begin to better define which
aspect(s) of soaring they wish to pursue.

Regards,
Bob - JMHO - W.

[Ian]

On 28 Sep, 23:44, Bob Whelan > wrote:

> Personally, I think the Gospel of Simplicity ought to be preached more,
> because so much of soaring does not REQUIRE the latest in bells and
> whistles be present in order for fledglings to begin spreading their
> wings in personally gratifying and safe ways.

I like to fly in silence. Two mechanical varios (PZL +/- 10 for
averaging and speed to fly, Winter +/- 2 for working the weak stuff).
Radio off, because if I wanted to yack away I'd be flying power. Yes,
I know I might go a bit further with an audio vario (and I do stick in
an old Cambridge occasionally). Yes, I know the radio might be useful
(and I do switch it on sometimes). But I don't soar to listen to beeps
or to achieve high numbers - I soar for the sheer joy of flying.

Yours in sentimental simplicity,

Ian

[Mike Borgelt]

Bill, not sure I should disillusion you. What is happening is that you are
entering air that is starting to rise. This caused the speed command
function of the B50 to call for slower airspeed. The warble starting is the
"fly slower" sound. So much of the time there will be some sort of thermal
coming up by which time you are going a little slower and it is easier to
pull in to it. When the relative reading exceeds the Macready setting the
audio switches to the climb "beep" sounds which ought to wake you up if you
haven't already noticed because you were concentrating on something else.

There is an approximately +/- 5 knots speed band where the lights will be
out(it varies with MacCready setting). The fly slower audio starts when the
first blue light comes on. The fly faster audio only starts when you would
be flying slower than zero MacCready for the air you are currently in. This
is more comfortable and means you are never flying slower than best
glide(this might answer the poster who wanted to know how to cross big areas
of sink and note that unless on final glide the wind doesn't matter in speed
to fly theory).

As for the number for the speed to fly, we display that on the B500 . It
does not change with the air as the lights and audio are for that but it
gives you an idea of the sort of speed you are aiming for when you acclerate
out of a thermal. B500 works like a B50 but has lots of extras including a
nav, glide and wind computer and some other refinements.

I had a Piep audio in my Salto along with a PZL mechanical for a couple of
years before I started building my own electric varios. That was nearly 35
years ago. The Piep audio had the problem that the zero point wasn't stable
with temperature - a common failing of early thermistor varios. Your
mechanical vario with flask might make a nice display piece for your office.
There's way better than that around. See B400 on our website. Yes I have
flown with mechanical varios and a Brand X flight computer not that long
ago. Three 4 hour flights in a Nimbus 4DM. Great glider, abysmal instruments
and I had been through and fixed leaks etc. I haven't had one in a glider of
mine since 1979.

Unless installed correctly the flask will screw up other varios on the same
TE line. This will be true even if the flask using vario is an electric
type.

The real problem with all TE varios at present is that horizontal gusts will
cause spurious readings. The problem gets worse with the square of the
TAS(See our website article). If you slow the vario response to get rid of
the problem you get rid of good information about vertical air motion
changes too. I've been going around in a thermal with a PZL and a B21 in a
customer's glider and seen the B21 show 1 knot on one side of the thermal
with peaks of 6 knots while the PZL sat on close to 2 knots all the way
round. Re centering on the B21 got me 5 knots on the averager. This was an
unusually smooth thermal and it was hard to tell by feel. A reasonably fast
responding vario is an advantage but there is a high workload in mentally
filtering the horizontal gust "noise" from the vertical "signals"

This may change soon.


Mike Borgelt

Borgelt Instruments






"Bill Daniels" <bildan@comcast-dot-net> wrote in message
. ..
> In addition to my old reliable B40, I have a newly old B50. As I'm
> cruising along the B50's audio will switch to slow yodel and two blue
> LED's will light up indicating the need to slow down "a lot". It's
> usually not clear to me why I should slow down but I've learned to trust
> it. After I enter the zoom I usually feel a kick in the pants as I enter
> a strong thermal. It seems to know a thermal is coming well before I do.
>
> Mike, HOW DOES IT DO THAT?
>
> Bill Daniels
>

[Paul Hanson]

At 01:36 29 September 2007, Mike Borgelt wrote:
>

>The real problem with all TE varios at present is that
>horizontal gusts will
>cause spurious readings. The problem gets worse with
>the square of the
>TAS(See our website article). If you slow the vario
>response to get rid of
>the problem you get rid of good information about vertical
>air motion
>changes too. I've been going around in a thermal with
>a PZL and a B21 in a
>customer's glider and seen the B21 show 1 knot on
>one side of the thermal
>with peaks of 6 knots while the PZL sat on close to
>2 knots all the way
>round. Re centering on the B21 got me 5 knots on the
>averager. This was an
>unusually smooth thermal and it was hard to tell by
>feel. A reasonably fast
>responding vario is an advantage but there is a high
>workload in mentally
>filtering the horizontal gust 'noise' from the vertical
>'signals'
>
>This may change soon.
>
>
>Mike Borgelt
>
>Borgelt Instruments
>
Maybe sooner than you may think! This is the main problem
that Dr Ludek Smolik's Yaw-Free probes are designed
to combat. for those who did not see my last post on
it, here is his answer to my query again, along with
links to probe info and a youtube video link showing
the swiveling action that makes these probes resistant
to yaw/gust errors (particularly the 2 and 3 way probes,
for reasons described below):
http://www.eaglebrandproducts.com/TEK_Probe_Prices_2006.pdf
and the Youtube video: http://youtube.com/watch?v=OpN9sYHF_yc
I am still awaiting the performance plots, and will
post
them when I get them.

Paul Hanson


Dear Mr. Hanson,

many thanks for your mail which reached me here in
Europe across New Zealand.

ItŽs very pleasant for me to serve you some information
on my project.
The probes are manufactured in Germany in a more or
less individual manner according to the pilots wishes.

The major step forward is the yaw-free pressure measurement
of all three important pressures at same place and
time. Time to time there are discussions on web or
in articles in magazines about the yaw dependence of
the so called TE-pressure, which is normally taken
as a velocity dependent under pressure due to the
vorticity behind an particular object like e.g. a small
tube.
But such discussion is just a half truth ! ItŽs obvious
that beside the TE-under pressure the static and total
pressure are very sensitive for �yawing�
too. The new probe improves the measurement by rotating
around the yaw axis significantly.
If you are interested on results, I can provide plots.

But the tenor is: if a standard TEK-probe has an spread
in the probe coefficient of 10 or 20% due to yaw angel
or air turbulences, for the new probe such spread is
0%.

It is hard to make meaningful photographs of the probes
because they all are black and look boringJ) Therefore
I send you a short video where the functionality and
the free rotatability around the yaw axis is demonstrated.
The two prongs of the �Y� shape are
the tubes for the TE-measurement and the orifices
for total and static pressure are mounted in the small
antennas in the forward direction.

Of course , the probes fit to all standard adapters
or if desired to a new type of 3 way adapter, where
all the sealing o-rings are mounted and accessible
on probe itself.

One word to the results, in principle itŽs difficult
to compare probes really meaningful simply using a
flume. Normally the flume does not simulate either
real air conditions nor the glider influences and last
not least the individual pilots behaviour.
For this reason only a measurement on the same place
and at the same time on one glider with a same type
of electronics can provide the best and direct comparison..
For this purpose I made a probe with 2 x 3 independent
orifices. 3 orifices build a standard probe the other
3 orifices are build like the yaw-free probe. Feeding
the data to two independent vario circuits and logging
the results one obtain a flight �seen�
from two different probes. This experiment is still
in preparation and is foreseen for next spring.

I hope this short overview gives some helpful information


Best Regards

Ludek Smolik

[Eric Greenwell]

wrote:

> Or just drag that Cherokee out West. The 1-26ers get in some amazing
> flights out here!
> Back to the subject.... and this may be a bit of a 'noob' question.
> Is there an instrument that will indicate the optimum speed to fly to
> get through large areas of HUGE sink, also taking into account winds?
> I have a very basic 302A FR, and an iPAQ with XCSoar.
> Hints?

As usual, "It Depends...", but assuming you have a speed ring or other
type of speed director:

-if maximizing your XC speed, follow the speed director, which should
already have your McCready setting in it.
-if you want to minimize your altitude loss in thermal conditions as you
transit sink, use a McCready setting of zero
-if it's wave or back side ridge sink where you want to minimize your
altitude loss transiting the sink, use a McCready setting with a XC
speed the same as the wind speed (this is an approxiamation). Going
*into* a 50 knot wind, that might mean a setting of 6 knots; going
*downwind*, that might mean a setting of -1 knot.

I don't know of any instrument that can determine what you are thinking,
so it's up to you to choose the appropriate setting.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[Henryk Birecki]

Eric Greenwell > wrote:

wrote:
>
>> Or just drag that Cherokee out West. The 1-26ers get in some amazing
>> flights out here!
>> Back to the subject.... and this may be a bit of a 'noob' question.
>> Is there an instrument that will indicate the optimum speed to fly to
>> get through large areas of HUGE sink, also taking into account winds?
>> I have a very basic 302A FR, and an iPAQ with XCSoar.
>> Hints?
>
>As usual, "It Depends...", but assuming you have a speed ring or other
>type of speed director:
>
>-if maximizing your XC speed, follow the speed director, which should
>already have your McCready setting in it.
>-if you want to minimize your altitude loss in thermal conditions as you
>transit sink, use a McCready setting of zero
>-if it's wave or back side ridge sink where you want to minimize your
>altitude loss transiting the sink, use a McCready setting with a XC
>speed the same as the wind speed (this is an approxiamation). Going
>*into* a 50 knot wind, that might mean a setting of 6 knots; going
>*downwind*, that might mean a setting of -1 knot.
>
>I don't know of any instrument that can determine what you are thinking,
>so it's up to you to choose the appropriate setting.

Not really an instrument but GPS_LOG WinCE program does the
appropriate calculations on a PDA.

Cheers,
Henryk Birecki

[Bill Daniels]

"Mike Borgelt" > wrote in message
...
>
>
> Bill, not sure I should disillusion you. What is happening is that you are
> entering air that is starting to rise. This caused the speed command
> function of the B50 to call for slower airspeed. The warble starting is
> the "fly slower" sound. So much of the time there will be some sort of
> thermal coming up by which time you are going a little slower and it is
> easier to pull in to it. When the relative reading exceeds the Macready
> setting the audio switches to the climb "beep" sounds which ought to wake
> you up if you haven't already noticed because you were concentrating on
> something else.


Whatever, it's the best STF vario I have ever used.

>
> There is an approximately +/- 5 knots speed band where the lights will be
> out(it varies with MacCready setting). The fly slower audio starts when
> the first blue light comes on. The fly faster audio only starts when you
> would be flying slower than zero MacCready for the air you are currently
> in. This is more comfortable and means you are never flying slower than
> best glide(this might answer the poster who wanted to know how to cross
> big areas of sink and note that unless on final glide the wind doesn't
> matter in speed to fly theory).
>
> As for the number for the speed to fly, we display that on the B500 . It
> does not change with the air as the lights and audio are for that but it
> gives you an idea of the sort of speed you are aiming for when you
> acclerate out of a thermal. B500 works like a B50 but has lots of extras
> including a nav, glide and wind computer and some other refinements.
>
> I had a Piep audio in my Salto along with a PZL mechanical for a couple of
> years before I started building my own electric varios. That was nearly 35
> years ago. The Piep audio had the problem that the zero point wasn't
> stable with temperature - a common failing of early thermistor varios.
> Your mechanical vario with flask might make a nice display piece for your
> office. There's way better than that around. See B400 on our website. Yes
> I have flown with mechanical varios and a Brand X flight computer not that
> long ago. Three 4 hour flights in a Nimbus 4DM. Great glider, abysmal
> instruments and I had been through and fixed leaks etc. I haven't had one
> in a glider of mine since 1979.
>
> Unless installed correctly the flask will screw up other varios on the
> same TE line. This will be true even if the flask using vario is an
> electric type.
>
> The real problem with all TE varios at present is that horizontal gusts
> will cause spurious readings. The problem gets worse with the square of
> the TAS(See our website article). If you slow the vario response to get
> rid of the problem you get rid of good information about vertical air
> motion changes too. I've been going around in a thermal with a PZL and a
> B21 in a customer's glider and seen the B21 show 1 knot on one side of
> the thermal with peaks of 6 knots while the PZL sat on close to 2 knots
> all the way round. Re centering on the B21 got me 5 knots on the averager.
> This was an unusually smooth thermal and it was hard to tell by feel. A
> reasonably fast responding vario is an advantage but there is a high
> workload in mentally filtering the horizontal gust "noise" from the
> vertical "signals"
>
> This may change soon.
>

The new variometry standard will be noise-free instantaneous response and
zero gust sensitivity, right?

Bill Daniels

[Dan G]

On Sep 28, 11:44 pm, Bob Whelan >
wrote:
> Personally, I think the Gospel of Simplicity ought to be preached more,
> because so much of soaring does not REQUIRE the latest in bells and
> whistles be present in order for fledglings to begin spreading their
> wings in personally gratifying and safe ways. Flight (in any form)
> costs more than remaining groundbound. Soaring flight as a niche
> certainly isn't cheap (in time or money or mental effort required), and
> any barriers (real or imagined) to achieving it are precisely that:
> barriers. I don't think soaring participants should be promoting Mark
> CXXIV widgets as a universal good, or worse, as necessary, to everyone
> getting into the sport.

Couldn't agree more - hence my comment that technology peaked with the
B40 :-).

I'm not a big fan of slavishly following the vario when cruising -
there's a lot of evidence that there's little to be gained in terms of
overall XC speed. In fact there's a very good chance that by the time
you've slowed up, you're in sink, and by the time you've accelerated,
you're in lift. A glider doing 70 knots is travelling at ~30 m/s -
allow for the seconds of the vario reacting, the pilot reacting, and
the glider responding to your control inputs and you'll have travelled
an easy 100 m - that is, you're effectively reacting to air that's 100
m behind you. Which probably won't be doing the same thing as the air
you're now in.

What's much more important in terms of XC speed is climbing fast - and
to do that you need an accurate, well set-up vario. Mechanicals suck
on that score, and as Mike says, they often take the fancy kit with
them unless they've been set up by an expert.

BTW, on the gust issue, there is another solution (though not nearly
as elegant as the rotating TE probe) - accelerometers. The Vega by
Triadis uses them for gust filtering, but I've not heard of any pilot
reports.


Dan

[Bill Daniels]

"Dan G" > wrote in message
ups.com...
> On Sep 28, 11:44 pm, Bob Whelan >
> wrote:
>> Personally, I think the Gospel of Simplicity ought to be preached more,
>> because so much of soaring does not REQUIRE the latest in bells and
>> whistles be present in order for fledglings to begin spreading their
>> wings in personally gratifying and safe ways. Flight (in any form)
>> costs more than remaining groundbound. Soaring flight as a niche
>> certainly isn't cheap (in time or money or mental effort required), and
>> any barriers (real or imagined) to achieving it are precisely that:
>> barriers. I don't think soaring participants should be promoting Mark
>> CXXIV widgets as a universal good, or worse, as necessary, to everyone
>> getting into the sport.
>
> Couldn't agree more - hence my comment that technology peaked with the
> B40 :-).
>
> I'm not a big fan of slavishly following the vario when cruising -
> there's a lot of evidence that there's little to be gained in terms of
> overall XC speed. In fact there's a very good chance that by the time
> you've slowed up, you're in sink, and by the time you've accelerated,
> you're in lift. A glider doing 70 knots is travelling at ~30 m/s -
> allow for the seconds of the vario reacting, the pilot reacting, and
> the glider responding to your control inputs and you'll have travelled
> an easy 100 m - that is, you're effectively reacting to air that's 100
> m behind you. Which probably won't be doing the same thing as the air
> you're now in.

This is a testable thesis.

Careful study of OLC logs show those with the best flights do indeed indulge
in 'dolphin flying'. Of course, not all zooms are successful, but on
average, they are. Successful 'dolphin flying' requires several things.
One, the thermals must be wide enough. Two, the glider must have good
penetration and three, the pilot must be using relatively high interthermal
airspeeds. (You can't zoom from a low airspeed.)

If you have SeeYou, set it up so there are four windows - three of equal
size on the right half of the screen stacked one above the other. On the
left half display the map view with the trace color set to vertical speed.
Set the top right window to a graph of true airspeed (IAS would be better
but it's not available). Set the middle right window to vertical speed and
set the bottom right window to altitude. Expand the time axis of the three
right windows to the maximum. Now, save this "desktop" so you don't have
set it up again - then animate the flight log.

Those pilots who are 'dolphin flying' will show a sharp reduction in speed
as lift is encountered and a jump of several hundred feet in altitude. If
the zoom is successful, the altitude trace will show a resumption of the
glide displaced upward from a estimated continuation of the pre thermal
encounter trace. In the statistical analysis, the zoomers will show D:h
ratios in the hundreds for their straight glides. Those pilot not zooming
in lift will show D:h values around their best L/D. Dolphin flying clearly
works, but you have to be good at it. The best pilots are really good at
it.

>
> What's much more important in terms of XC speed is climbing fast - and
> to do that you need an accurate, well set-up vario. Mechanicals suck
> on that score, and as Mike says, they often take the fancy kit with
> them unless they've been set up by an expert.

No arguement. The best climbers easily win the day. It's amazing to see
OLC traces on SeeYou where the vertical speed trace shows a sine wave
matching the circle time. This clearly shows the pilot is not centered in
the thermal. The best pilots will show an average climb rate 2-3 knots
better than the average pilot on the same day. The pilot who are good at
zooms are also good at selecting and centering thermals - often on the first
turn.

>
> BTW, on the gust issue, there is another solution (though not nearly
> as elegant as the rotating TE probe) - accelerometers. The Vega by
> Triadis uses them for gust filtering, but I've not heard of any pilot
> reports.
>
In secret laboratories around the world they are working on the dreaded
"Inertial Variometer" that will change everything.:)

Bill Daniels

[Eric Greenwell]

Dan G wrote:

> BTW, on the gust issue, there is another solution (though not nearly
> as elegant as the rotating TE probe) - accelerometers.

I think I understand how accelerometers could distinguish between a
horizontal gust and the vertically moving air in a thermal, but I don't
understand how aligning the probe with the horizontal gust will reduce
it's effect on the vario. Wouldn't that accentuate, rather than
attenuate, the gust effect?

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[[email protected]]

Bill, are you seeing the effect of "dolphin" flying, or just following
the lines of energy (or, avoiding sink). I try real hard to avoid the
classic "pull hard in lif" type of dolphin flying, since in my
experience it slows me down (from comparison flying); OTOH, I try real
hard to look for and exploit lift lines, and gently vary speeds to
match the trend of the airmass. Doing this, I consistently better my
polar's L/D for the speed being flown.

Of course, this is semantics - whatever technique being used, it is a
skill that takes knowledge, practice, and good instruments.

And the fast pilots usually have all three!

Kirk
66

[Paul Hanson]

At 03:06 30 September 2007, Eric Greenwell wrote:
>Dan G wrote:
>
>> BTW, on the gust issue, there is another solution
>>(though not nearly
>> as elegant as the rotating TE probe) - accelerometers.
>>
>
>I think I understand how accelerometers could distinguish
>between a
>horizontal gust and the vertically moving air in a
>thermal, but I don't
>understand how aligning the probe with the horizontal
>gust will reduce
>it's effect on the vario. Wouldn't that accentuate,
>rather than
>attenuate, the gust effect?
>
>--
>Eric Greenwell - Washington State, USA

Not at all, at least not if it is the 2 or 3 way probe
and this is why. It is first and foremost the static
system that is particularly sensitive to gusting. When
a horizontal gust hits the side of a plane, it creates
positive pressure on one side of the static inputs
(whether fuse or probe mounted), throwing the reading
way out of whack. With the static on a rotating probe,
it can align itself to always face directly into the
wind and alleviate the big errors in static reading
that horizontal gusts ( or other disturbances in yaw)
create. It does not hurt to have the TE also rotate
with it, and does not hurt to have the dynamic rotate
as well (with rotating dynamic, a cup shaped Kiel tip
is not required to maintain accuracy-less drag) but
dynamic and TE are not as sensitive to misalignments
in airflow as the static system is. This probe system
will provide accurate readings during both slipping
maneuvers (like if you mildly slip while thermalling
ala Holighaus) as well as gusting incidents. BTW, the
'fancy' 2 way probe Dr Smolik sells is only 80 Euros,
and the 3 way probe only 99. This video is the 3 way
probe:
http://youtube.com/watch?v=OpN9sYHF_yc , and this link
shows drawings and prices for the whole line:
http://www.eaglebrandproducts.com/TEK_Probe_Prices_2006.pdf
I am only assuming here, but I would imagine these
probes to be much cheaper than an accelerometer compensated
computerized vario system (not to mention compatible
with most anyone's current setup) but perhaps maybe
not as effective in all situations. It is a simple
and elegant aerodynamic solution to an old problem,
that I'm sure will be seen on many more gliders in
the near future. Again, I will share the data tables
Ludek provides, once he sends them to me.

Paul Hanson

PS. I have no financial involvement with these probes,
I just think they are very cool.
PPS. there is a reason that NASA and most other flight
test groups use static/dynamic (they don't mess with
TE) probes that rotate (in 2 axis) to keep readings
accurate while evaluating aircraft.

[Bill Daniels]

I think that if the airspeed is reduced by 40 knots or so in, say, 20
seconds, that's a zoom. I often see a quicker speed reduction than that. I
would agree than smooth control inputs are better. Timing of the airspeed
changes is more important than the amount.

The key as to whether it worked or not is the barogram trace. If the
downward trend of the glide is displaced upward at the zoom so a new trend
starts at the top of the zoom, there was a net gain. If the thermal was too
narrow or was followed by heavy sink, the barogram trace will just show a
spike with no change in the trend - just a loss in average speed due to the
slowing.

A couple of pilots who seem to be the masters of the "Long Glide" are Kevin
Wyatt and Gary Ittner. You will notice that their airspeed trace is almost
an exact inverse of the vario trace. i.e. vario up, arispeed down and vario
down airspeed up.

On the other hand you will see pilots where there is only a weak correlation
between airspeed and vario. These folks seldom get more than the published
L/D.

Bill Daniels


> wrote in message
oups.com...
> Bill, are you seeing the effect of "dolphin" flying, or just following
> the lines of energy (or, avoiding sink). I try real hard to avoid the
> classic "pull hard in lif" type of dolphin flying, since in my
> experience it slows me down (from comparison flying); OTOH, I try real
> hard to look for and exploit lift lines, and gently vary speeds to
> match the trend of the airmass. Doing this, I consistently better my
> polar's L/D for the speed being flown.
>
> Of course, this is semantics - whatever technique being used, it is a
> skill that takes knowledge, practice, and good instruments.
>
> And the fast pilots usually have all three!
>
> Kirk
> 66
>

[Eric Greenwell]

Paul Hanson wrote:
> At 03:06 30 September 2007, Eric Greenwell wrote:
>> Dan G wrote:
>>
>>> BTW, on the gust issue, there is another solution
>>> (though not nearly
>>> as elegant as the rotating TE probe) - accelerometers.
>>>
>> I think I understand how accelerometers could distinguish
>> between a horizontal gust and the vertically moving air in a
>> thermal, but I don't understand how aligning the probe with the horizontal
>> gust will reduce it's effect on the vario. Wouldn't that accentuate,
>> rather than attenuate, the gust effect?
>>
>> --
>> Eric Greenwell - Washington State, USA
>
> Not at all, at least not if it is the 2 or 3 way probe
> and this is why. It is first and foremost the static
> system that is particularly sensitive to gusting. When
> a horizontal gust hits the side of a plane, it creates
> positive pressure on one side of the static inputs
> (whether fuse or probe mounted), throwing the reading
> way out of whack. With the static on a rotating probe,
> it can align itself to always face directly into the
> wind and alleviate the big errors in static reading
> that horizontal gusts ( or other disturbances in yaw)
> create.

The gusting that cause false readings on my varios seems small enough
that it doesn't move the yaw string very much. I can use the rudder to
slip/skid the same amount, and the vario hardly notices it. So it seems
like the gust itself is the problem, not the direction it comes from. If
that's true, an aligning probe won't help any.

Also, suppose the gust comes directly from the front or the back. This
will cause a change in the airspeed and "fool" a TE vario. A probe that
aligns with the airflow won't help in this case, as the airflow
direction doesn't change at all.

It does not hurt to have the TE also rotate
> with it, and does not hurt to have the dynamic rotate
> as well (with rotating dynamic, a cup shaped Kiel tip
> is not required to maintain accuracy-less drag) but
> dynamic and TE are not as sensitive to misalignments
> in airflow as the static system is.

If that's the case, why don't we just use a TE probe and forget about
using a pitot/static system to run the vario?

> This probe system
> will provide accurate readings during both slipping
> maneuvers (like if you mildly slip while thermalling
> ala Holighaus) as well as gusting incidents.

It seems like the aligning probe ensures that a gust will add it's
entire velocity to the glider's speed through the air, making it even
more sensitive to gusts than a probe that doesn't align.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[Martin Gregorie[_1_]]

Paul Hanson wrote:
> When
> a horizontal gust hits the side of a plane, it creates
> positive pressure on one side of the static inputs
> (whether fuse or probe mounted), throwing the reading
> way out of whack.
>
I can see that this would make the ASI twitch (and the altimeter if it
wasn't on cockpit pressure) but I don't see the relevance to my varios
because:

- my B.40 only has one line that connects to the TE probe, so the static
isn't affected and you say that a TE probe is relatively little
affected by gusts.

- my SDI C4 which has static and pitot as well as TE connections.
My guess is that it only uses TE for its vario function and the
static+pitot for airspeed and pressure altitude.

BTW, what the heck is a "dynamic pressure" probe? Is it a pitot tube?


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

[Paul Hanson]

At 12:06 08 October 2007, Martin Gregorie wrote:
>Paul Hanson wrote:
>> When
>> a horizontal gust hits the side of a plane, it creates
>> positive pressure on one side of the static inputs
>> (whether fuse or probe mounted), throwing the reading
>> way out of whack.
> >
>I can see that this would make the ASI twitch (and
>the altimeter if it
>wasn't on cockpit pressure) but I don't see the relevance
>to my varios
>because:
>
>- my B.40 only has one line that connects to the TE
>probe, so the static
> isn't affected and you say that a TE probe is relatively
>little
> affected by gusts.

Relative being a relative term, this is somewhat true.
In comparison it is not AS affected as the static,
but it is indeed affected. There are many plumbing
combos for different types of system, so while something
that works well with one system does not mean it will
work for another. Although in this case, I do believe
you would get better readings from your B-40 with the
Yaw-free TEK probe. Read the stats on the charts for
yourself that I am posting links to in a new post,
that compare a standard TE and a yawing unit under
the same conditions.

>- my SDI C4 which has static and pitot as well as TE
>connections.
> My guess is that it only uses TE for its vario function
>and the
> static+pitot for airspeed and pressure altitude.
>
Without actually studying your system your guess is
only that-a guess. Just because the B-40 runs only
on TE does not mean that this one does, although it
may. Rather than guess though, I would do my homework
to figure that out if it were mine before deciding
how to improve anything.

>BTW, what the heck is a 'dynamic pressure' probe? Is
>it a pitot tube?

Dynamic pressure is what a Pitot tube is measuring,
and what a TE is attempting to create a perfectly matched
inverse of.

Paul Hanson
"Do the usual, unusually well"--Len Niemi

[Martin Gregorie[_1_]]

Paul Hanson wrote:
>
> Dynamic pressure is what a Pitot tube is measuring,
> and what a TE is attempting to create a perfectly matched
> inverse of.
>
Clear and concise. Thanks!


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