Multiple varios

[John Foster]

Why do so many gliders seem to have multiple varios? Is it that critical to have a back-up for this instrument? Do they often fail and leave you in "
the lurch"?

[Darryl Ramm]

On Thursday, December 14, 2017 at 2:00:23 PM UTC-8, John Foster wrote:
> Why do so many gliders seem to have multiple varios? Is it that critical to have a back-up for this instrument? Do they often fail and leave you in "
> the lurch"?

Physiological warfare.
Feeling of inadequacy/vario envy.
Folks wanting multiple things like different time constants/settings.
Display of "other stuff" when the displays start being multi function displays.
Alternate source, e.g. electronic comp vs TE probe
Hiding ugly holes in the panel.
Backup (they really don't fail often if looked after).

[Roy B.]

John:
This is a subject on which experienced glider pilots will disagree on. Many now use electronic instruments exclusively, in which case a single good vario is the norm. Others - who have doubts about battery sustainability (especially on long flights) will want a mechanical back up. I've had batteries fail very far from home and was happy to have a mechanical vario backup. Or it may depend on your OCD medication level . . .
Roy

[drguya...@gmail.com]

Span matters!
Since all gliders are built the same, you can express your personality through your panel.

[Papa3]

Let's talk politics - it's less controversial.

But seriously, I've always liked having a good (simple) mechanical vario backing up whatever electronic wizardry is the flavor of the month/year. I do from time-to-time like to compare readings, response rates, etc. just to make sure the morons, the neurons, and fig-newtons in the electronic instrument are behaving. In fact, I discovered a hardware/software problem this year when I started to notice consistent differences between the two instruments.

In 30 years of XC gliding, I'd say I've actually had to rely on the mechanical backup maybe 3 times when the electrics went south. Not exactly a compelling reason, but we're creatures of habit.

Erik Mann (P3)

[Andrzej Kobus]

On Thursday, December 14, 2017 at 5:00:23 PM UTC-5, John Foster wrote:
> Why do so many gliders seem to have multiple varios? Is it that critical to have a back-up for this instrument? Do they often fail and leave you in "
> the lurch"?

Or you simply need to buy a new toy.

[Tony]

man with two watches never knows what time it is.

and the guy with 3 or 4 varios never knows how strong the thermal is either.

[John Foster]

On Thursday, December 14, 2017 at 3:54:47 PM UTC-7, Tony wrote:
> man with two watches never knows what time it is.
>
> and the guy with 3 or 4 varios never knows how strong the thermal is either.

That's what prompted my question.

[uncl...@ix.netcom.com]

On Thursday, December 14, 2017 at 5:00:23 PM UTC-5, John Foster wrote:

> Why do so many gliders seem to have multiple varios? Is it that critical to have a back-up for this instrument? Do they often fail and leave you in "
> the lurch"?

I have a mechanical vario as a second because it will get me home if I have a complete electrical failure. That and a chart is all I need to get back.
And yes it has happened.
UH

[Kiwi User]

On Thu, 14 Dec 2017 14:46:15 -0800, Papa3 wrote:

> In 30 years of XC gliding, I'd say I've actually had to rely on the
> mechanical backup maybe 3 times when the electrics went south. Not
> exactly a compelling reason, but we're creatures of habit.
>

I used exactly the same reasoning as Papa3, but fitted two electronic
varios. The main one is entirely dependent on the main glider battery.
The other normally runs off the main battery but also has a 9v PP3
strapped to its rear that can run it for 8-10 hours if the main battery
fails.

I do in fact glance at it for confirmation while hunting for thermals,
because it has a much faster response than my main vario and I also
prefer it when ridge running because, unlike my main vario, it makes
'sink' noises as well as 'climb' ones.


--
Martin | martin at
Gregorie | gregorie
| dot org

[Retting]

or.....
I seldom look at a vario but rely on its audio tuned and honed to my brain. I've become so wired to the nuance of the Borgelt pitch, that when the speaker quit during a race, I turned on my 'back-up' CAI 302 audio only to discover it had a totally different pitch. WTF shot thru my brain and took more than a few thermals to get into some form of race mode. I had Tim jet me a new Borgelt overnight just for the audio.
Lucky (very) for me, progression into the CN xc as my back-up data logger, navigation, vario happens to have an audio pitch that matches my Borgelt.
The Borgelt also has, as others varios do, a AA battery back-up to come home on should an electrical issue arise.
After 14 years, 49 races, 3000+ hours of thermaling listening to the same audio, I know within 50'am the strength of the thermal, or sink.
The audio is critical to maintaining the highest level of safety towards aircraft separation and collision avoidance as well as information intake by.....
keeping the eyes outside. Gliders, birds, gliders, clouds, gliders.....pig farm, walmart (got low), gliders, clouds.
I want two audios in my cockpit.
14 years? 3000 hours? gheez....boy do I suck at racing.

R

[mark...@aol.com]

"More is always better"? Hardware solution to a software (lack of skill) problem"

More seriously, systems failures a Long Way From Home over Moonscape and/or not wanting to abort a great flight are good reasons for an independent backup vario. Survival XC soaring using seat of the pants plus altimeter is not fun.

Or just to enjoy the beauty, precision, and sensitivity of the Sage/Schuemann mechanical vario. A stunning device.l

[Surge]

On Friday, 15 December 2017 00:00:23 UTC+2, John Foster wrote:
> Why do so many gliders seem to have multiple varios? Is it that critical to have a back-up for this instrument? Do they often fail and leave you in "
> the lurch"?

I removed my mechanical backup vario when I upgraded my electronic vario.
My backup vario is XCSoar on an Android phone in my pocket. Sure, it's uncompensated but I've flown with uncompensated varios in the past and it's not that hard if you maintain a constant speed while thermalling.
If both fail and I can't stay aloft then I'll park my glider in a farmers field.
The same argument applies to relying solely on GPS vs using a compass and map as a backup. Where I fly if I get lost I'll just land out. No sweat.

I can understand people having backup instruments if they fly over hostile terrain with few out-landing opportunities.

[ors...@gmail.com]

The mechanical vario is mandatory as per EASA glider certification (as mech. anemometer, mech. altimeter and mech. compass). The electronic vario is usually linked to the computer with many other features (final glide, etc...).
The concept behind that is: if you have a battery failure you still come back home with the 4 essential instruments.

[Tango Whisky]

Le vendredi 15 décembre 2017 07:17:22 UTC+1, Surge a écrit :
> I removed my mechanical backup vario when I upgraded my electronic vario.
> My backup vario is XCSoar on an Android phone in my pocket. Sure, it's uncompensated but I've flown with uncompensated varios in the past and it's not that hard if you maintain a constant speed while thermalling.
> If both fail and I can't stay aloft then I'll park my glider in a farmers

Try that in high wind conditions and rotors in the mountains, with landing sites 20 miles apart.
Been there, done that, no fun.

[Alex]

> The mechanical vario is mandatory as per EASA glider certification (as mech. anemometer, mech. altimeter and mech. compass). The electronic vario is usually linked to the computer with many other features (final glide, etc...).

For my LS8 the vario is not listed as minimum equiptment. I have the new Air Avionics electronic altimeter which is ETSO certified and complies with the requirements stated in the LS8 maintenance manual.

I was not able to find any regulations prohibiting electric minimum instrumentation in EU or German national law. Do you have any reference to support your statement?

[krasw]

On Friday, 15 December 2017 10:07:15 UTC+2, ors...@gmail.com wrote:
> The mechanical vario is mandatory as per EASA glider certification (as mech. anemometer, mech. altimeter and mech. compass). The electronic vario is usually linked to the computer with many other features (final glide, etc...).
> The concept behind that is: if you have a battery failure you still come back home with the 4 essential instruments.

You confuse airspeed indicator (which is mandatory) with variometer.

[flgliderpilot]

Often there is just a mechanical vario and an electronic vario. One needs no power :)

[krasw]

I have yet to fly a glider which has electrical and mechanical variometer that display identical signal all the time. Until then i feel that both mechanical and electrical variometers give more information about the airmass than single one.

[Tango Eight]

On Friday, December 15, 2017 at 10:12:52 AM UTC-5, krasw wrote:
> I have yet to fly a glider which has electrical and mechanical variometer that display identical signal all the time. Until then i feel that both mechanical and electrical variometers give more information about the airmass than single one.

Mechanical plays hell with modern (pressure transducer type) electric on same TE circuit. In that event, the mechanical may well be giving the better information.

Results vary depending upon pneumatic impedance of your TE probe and other things...

best,
Evan Ludeman / T8

[Mike C]

One mechanical(Sage)on a TE probe and one Westerboer STF with Electronic Compensation. Seems to be an ideal combination. Always check the Sage before I turn.

Mike

[Dan Marotta]

Yeah, I needed a new toy so I bought a Cessna 180.  Its audio is louder
than my ClearNav XC vario.
--
Dan, 5J

[john firth]

On Thursday, December 14, 2017 at 5:00:23 PM UTC-5, John Foster wrote:

> Why do so many gliders seem to have multiple varios? Is it that critical to have a back-up for this instrument? Do they often fail and leave you in "
> the lurch"?

There is only one essential instrument for VFR and it lies between you ears.
a vario is next, with a vent to cockpit static if the TE gets plugged.

BTW, which Elec varios have an audible sink alarm; the old Cambridge audio was useless in sink as airspeed noise over 60-70 kts covered the LF tone.

In 1970, I built an analogue vario-computer with audio, head up speed to fly reader, TE comp etc..and audio rising tone in lift, and broken tone louder and rising in sink. Just what I needed , but the transducers gave trouble.

John F

[chip.b...@gmail.com]

"Getting home" may well be possible if your only vario fails. Continuing to race if it fails in a contest is a lot more difficult. It's happened to me at least twice. I don't like single points of failure. The battery, battery selector switch, etc., can be one. The ubiquitous triple probe can be another another.

And, yes, the two varios do sometimes provide different insights.

Chip Bearden

[Kiwi User]

On Fri, 15 Dec 2017 12:24:37 -0800, john firth wrote:

> BTW, which Elec varios have an audible sink alarm; the old Cambridge
> audio was useless in sink as airspeed noise over 60-70 kts covered the
> LF tone.
>

Borgelt B.40 (and probably other Borgelts as well).

SDI C3 and C4 (he says, naming varios I have a lot of time in the air
with). These have two tomes for climb/sink in climb (TE) mode and another
two for speed up/slow down in cruise (super Netto mode), but my C4
doesn't have a silent band between lift/sink in climb mode, so I turn the
sink option off because I don't need a sink noise to tell me I'm in
searching for lift in somewhat bouyant air at best glide that's just
reducing my sink speed half the dead air value.

This lack of a silent band is a bad feature, of a lot of varios including
some of the LX ones. Ideally it should default to the region between zero
sink and -2kts and its lower limit should be configurable.

[bpatt...@yahoo.com]

Many years ago Mario Crosina and I launched in the Central Valley for our first flight of the season. My airspeed failed immediately and Mario's vario died. We developed a new form of team flying on the spot and did a nice x-country.

I had a problem this year with my Cnav audio and discovered it was almost impossible to thermal by looking
Inside after over 30 years of listening to an audio nag. Try turning off your audio some time, hopefully you will find it has become an essential item when flying.

Bruce Patton

[Dan Marotta]

The ClearNav XC Vario emits a sink tone.

--
Dan, 5J

[Darryl Ramm]

And thank God you can disable it :-)

[JS]

This question may have more answers than there are pilots.
Jim

[krasw]

I had two TE probes in my previous glider, and made a some experiments how much mechanical variometer (Bohli and 0,35l bottle) affect electrical variometer. I flew both variometers with same TE tube or totally isolated TE systems. I could very easily tell different between two different TE probes, but could not see any meaningful difference in electrical vario behaviour if mechanical variometer was connected or not. After flying excellent electrically compensated system last summer I'm thinking that might be way to go in future.

[Dan Marotta]

You don't need to disable the sink tone - simply fly in lift!

--
Dan, 5J

[Tango Eight]

Good for you for testing and paying attention. On my system (I have a 1980s vintage venturi style triple probe, the venturi being at the end of a very restrictive small tube) the capacity / flow of a std Winter vario turns any modern electronic vario into something useless. So my options are either use electronic compensation for the electronic and leave the TE probe for a mechanical, or (current setup) use a B400 as backup (with 4xAA).

"Electronic" compensation can work better than a TE probe. You can't ever get quite to 100% TE compensation with a probe but you can get anything you want with (probe sourced) pitot + static and a good vario. Compensation becomes more critical as TAS and wingspan go up. What works cruising at 80 kts & 6000' won't necessarily cope with 130 (true) and 16,000.

I've been using probe P & S with electronic comp in CNv for a couple of seasons. CNv has the interesting property that one can switch from TE probe to electronic, as well as trim the electronic compensation in flight. Works for me.

Evan Ludeman / T8

[Brian]

I tried getting home once on just the Mechanical Vario, while doable, it was very shortly afterwards I bought the B40 with the battery backup and replaced my Mechanical Vario with it so if it happened again I would have an audio.
I don't recall every having to use the B40 as my primary, but maybe that just means it was such a no-event I don't remember it.

I also had the B40 running of the TE prove and the Cambridge running off the pitot and Static (electronically compensated) they indicated pretty close, but was nice know they were working off 2 completely independent systems.

Brian

[Charlie M. (UH & 002 owner/pilot)]

I did a flight many years ago in a ASW-20 in the spring. The "normal" checks said everything was fine.
Crossing 200' on tow, nothing added up.
Result was a mouse chewed hole in a TE probe tubing.
It was a 3hr flight, mostly seat of the pants and sound.
No ASI, no vario.......

While I have not had an electrical failure, it's nice to have a mechanical vario.
Yes, I really miss the audio, but for fun flying, butt vario and a mechanical gauge is good enough.
Yes, this is in eastern US, so not major issues with wave or ridge.

BTW, my first audio vario was a Development vario from Cambridge ( yes, Raouf Ismail) from when I crewed for him in Elmira. It was in SGS-1-26 SN 002 for many years. I still have the paperwork for it, we still have it.
Gosh, I have loved an audio vario since then.

And as others have stated, a paper map and mechanical instruments may get you home.......at least....in the eastern US. Not sure about the mountains in the west.

[Chris Short]

These are popular in the paragliding community. Tiny audio only vario.
Obviously not TE though.

https://skybean.eu/skybean-vario

Would this be a reasonable backup in conjunction with a non-audio
mech vario?

[kev...@gmail.com]

I have three various in my panel. All are electronic and two have their own TE systems and separate bottles. The third is the averager on the flight computer. One of the various is a dedicated netto. The borgelt is battery backed up. If one fails the others are not perfect and will allow the flight to continue.

[Tom BravoMike]

On Thursday, December 14, 2017 at 4:00:23 PM UTC-6, John Foster wrote:
> Why do so many gliders seem to have multiple varios? Is it that critical to have a back-up for this instrument? Do they often fail and leave you in "
> the lurch"?

Maybe I'm missing something, but it looks like nobody in this thread has mentioned the advantage - once you have more than one vario - of different scale ranges. I can remember most of our club gliders had two varios: one up to 5m/s and the other one up to 10 or 30 m/s.

[Ross]

Pretty sure Ray Lynskey had a 30kt vario in his glider. Not to know how fast he was going up, but how fast he was coming down in the wave

[Mike C]

I had set a different range and response time on my Westerboer 1020 than the scale on the Sage but did not find any real advantage and changed the range back.

Mike

[Bruce Hoult]

On Monday, December 18, 2017 at 12:29:04 AM UTC+3, Ross wrote:
> Pretty sure Ray Lynskey had a 30kt vario in his glider. Not to know how fast he was going up, but how fast he was coming down in the wave

I'm trying to think what you could do with this information that would be useful to you.

It's not like a reading between -10 and -30 will make you fly faster than simply knowing it's pegged at -10. You'll already be flying as fast as you dare!

You're also probably not going to think to yourself "Oh good, I got out of that region of -25 and it's only -15 here ... I'll just circle here for a bit..."

[Rhubarb]

I guess you may be able to see a trend which could be useful

[Bruce Hoult]

On Monday, December 18, 2017 at 2:46:48 PM UTC+3, Rhubarb wrote:
> I guess you may be able to see a trend which could be useful

At those rates I reckon you can see the speed of the altimeter spinning easily enough :-) :-)

Still, if you find it useful it's not a big investment to get a GA VSI. I found a site with +/- 2000 fpm VSIs for $195, +/- 3000 fpm for $225. Those are less than half the price gliding 10 knot Winters seem to go for. 6000 fpm VSIs are a bit more expensive ... I can only assume because they have limited demand (especially for climb), because they should be easier to make!

https://www.pacificcoastavionics.com/category/121-vertical-speed-indicators.aspx

And most likely the first thing I found isn't the cheapest.

[gregg...@gmail.com]

GA VSI's generally lag @ 8 seconds

[Charlie M. (UH & 002 owner/pilot)]

In severe conditions, making a field 3 miles away may make the difference depending on sink rate.
No, I have not been in that position.
Yes, I know others that have.......where the standard 1000FPM is maxed, still relevant info.

For me, I hedge my bets. Never had the electrics fail, but have had SEL electrics fail on the ground.
Also, sometimes, nice to compare 2 different varios while flying.

[Bruce Hoult]

On Monday, December 18, 2017 at 8:34:13 PM UTC+3, Charlie M. (UH & 002 owner/pilot) wrote:
> In severe conditions, making a field 3 miles away may make the difference depending on sink rate.

But how is a vario with a larger range going to help the situation?

If you want to know if you're currently going to make it or not, look out the window and see if your proposed field is rising or sinking in the canopy.

[Dan Marotta]

GASP!  Actual pilotage?  Say it ain't so...
--
Dan, 5J

[Tom BravoMike]

I guess there are no noteworthy advantages in 'normal' conditions. The 10 or 30 m/s varios were probably meant for extreme conditions which may happen during a rotor/wave or storm front flight. Otherwise you prefer the low range for visibility and accuracy.

[Bruce Hoult]

Yes, I've flown in such wave. I just don't know what I'd do differently if I had a vario that said I was going down at 20 knots rather than knowing simply that the vario was pegged at -10 and the big hand on my altimeter was unwinding at 100 feet every three seconds.

It's actually quite easy to see the difference between 1000 fpm (100 ft in six seconds) and 3000 fpm (100 ft in two seconds) from the altimeter alone. I know.

[herron...@gmail.com]

Actually, I find the second vario quite useful. In straight flight I have my V-7 set on netto, but when there's a mild surge it's always a question, is this an actual thermal or just a change in air movement? The Winter tells me right away, and I can make a quick decision: turn or keep going.

[Darryl Ramm]

On Saturday, December 30, 2017 at 9:57:00 AM UTC-8, herron...@gmail.com wrote:
> Actually, I find the second vario quite useful. In straight flight I have my V-7 set on netto, but when there's a mild surge it's always a question, is this an actual thermal or just a change in air movement? The Winter tells me right away, and I can make a quick decision: turn or keep going.

A Winter variometer cannot tell you anything "straight away".

[jj9x...@gmail.com]

Maybe not in real life, but in the lab (or the workshop) the response of a Winter vario can be much faster than more modern instruments based on pressure transducers.

The video at https://www.youtube.com/watch?v=XmgHBkuVI5Q&feature=youtu.be shows the response of a Winter variometer and an LX 5000 connected to the same TE line. The pressure is quickly reduced by about 1 hPa, and the variometers indicate the corresponding lift. The LX 5000 was at the shortest possible time constant and minimum filtering.

The test was initially performed to see if the Winter with a capacity flask would affect the reading of the LX 5000. That was not the case; the LX 5000 had the same response with and without the Winter connected to the TE line.
The Winter vario reacts almost instantaneously to the pressure change, whereas the LX 5000 needs some time to react (basically given by the set time constant). However, the Winter decays exponentially (and slowly) back to zero and the LX 5000 does eventually catch up. This difference in behavior is easily modeled from the different working principles for the two types of instruments, and similar results have also been observed with more recent LX instruments.

In the lab, flow-based varios like the Winter react faster to sudden changes in air movement than pressure transducer varios. Is it the same in real life?

Jan

[Kiwi User]

"It depends"

IME (slowest->fastest) flow varios I've flown with, this feels right:
PZL, Winter, Sage

IME the PZL is a lot slower than any pressure sensing vario I've used.
I normally fly with old varios (SDI C4 and Borgelt B.40). The C4 has
about the same response rate as other pressure varios of similar age and
the B.40 is very noticeably faster.


--
Martin | martin at
Gregorie | gregorie
| dot org