Non-TE probe compensation

[Ale.L (RL)]

Hi folks!

Has anyone had any experience with non-TE compensated vario systems? From what I gather there're a few options out there:

* There's the varios (and flight computers with integrated varios) like the CAI 302 and LxNav V7 that have electronic compensation as an option. Any others out there?

* There's also the Schuemann box. They are hard to come by so if anyone can share any experience with those that'd be much appreciated.

* And there's the diaphragm type total energy compensators like the PZL KWEC.

Any other options out there?

If you can share your thoughts and the pros/cons in your experience with each of these systems and how it compares to a system with a regular TE probe I'd be very thankful.

Cheers,

Ale.L (RL)

[BG[_4_]]

Hard to better than a well designed TE probe. Adding the pitot information does a lot more than add the potential for TE to a glide computer. It gives accurate winds with the help of GPS.

If you are looking for the best TE system, a well designed and implemented probe is hard to beat.

Buzz

[JS]

It's been ages since flying with a Scheuemann box. Probably the analog version of what you're after.
The CAI302 and CNv both do great on electronic TE. Still waiting for CNv sensor functionality.
The Butterfly (Air Avionics) vario is amazing using a well-positioned sensor unit.
Jim

[Tim Taylor]

I don't remember the V7 having a non-TE option. I fly with a V7 hooked to my TE Probe and a 302 electronically compensated. They are very similar in response so I have been impressed how well the 302 works non-TE. I configured my panel so that the two varios would be independent in case I lost the TE system for some reason.

As for the B Box, not sure anyone knows how to service one now. They have tubes that are likely rotted inside so I would not trust one. I have one on the self but have never used it.

TT

[Mike C]

On Monday, January 26, 2015 at 7:47:59 PM UTC-7, Ale.L (RL) wrote:
> Hi folks!
>
> Has anyone had any experience with non-TE compensated vario systems? From what I gather there're a few options out there:
>
> * There's the varios (and flight computers with integrated varios) like the CAI 302 and LxNav V7 that have electronic compensation as an option. Any others out there?
>
> * There's also the Schuemann box. They are hard to come by so if anyone can share any experience with those that'd be much appreciated.
>
> * And there's the diaphragm type total energy compensators like the PZL KWEC.
>
> Any other options out there?
>
> If you can share your thoughts and the pros/cons in your experience with each of these systems and how it compares to a system with a regular TE probe I'd be very thankful.
>
> Cheers,
>
> Ale.L (RL)

The Westerboer 1020 Vario has electronic TE. Works well.

[John Galloway[_1_]]

The choice of vario is far less important than quality of the pressure
sources. For electronic TE to work well you need very accurate static
and dynamic pressure sources. In practice that means a pitot/static
probe. If you don't have that then stick with a TE probe - the best of
which is the ESA- systems twin prong probe mounted with the
prongs horizontal.

In a perfect world an ESA-system triple probe gives you the option of
the best possible TE probe or electronic compensation.

Like many others I have an LX 9000 and the triple probe. Very much
to my surprise I find it better set up for electronic TE than probe TE.

John Galloway

At 08:03 27 January 2015, Mike C wrote:
>On Monday, January 26, 2015 at 7:47:59 PM UTC-7, Ale.L (RL)
wrote:
>> Hi folks!
>>
>> Has anyone had any experience with non-TE compensated vario
systems? From
>what I gather there're a few options out there:
>>
>> * There's the varios (and flight computers with integrated varios)
like
>the CAI 302 and LxNav V7 that have electronic compensation as an
option.
>Any others out there?
>>
>> * There's also the Schuemann box. They are hard to come by so if
anyone
>can share any experience with those that'd be much appreciated.
>>
>> * And there's the diaphragm type total energy compensators like
the PZL
>KWEC.
>>
>> Any other options out there?
>>
>> If you can share your thoughts and the pros/cons in your
experience with
>each of these systems and how it compares to a system with a
regular TE
>probe I'd be very thankful.
>>
>> Cheers,
>>
>> Ale.L (RL)
>
>The Westerboer 1020 Vario has electronic TE. Works well.
>

[[email protected]]

I have flown with a Winter or Sage connected to the TE probe and a C302 on 100% electronic compensation. Very little difference. In fact, I prefered the C302 because it was less jumpy and didn't seem to be giving me as many false indications of lift due to horizontal gusts.

[Richard[_9_]]

On Monday, January 26, 2015 at 10:04:12 PM UTC-8, Tim Taylor wrote:
> I don't remember the V7 having a non-TE option. I fly with a V7 hooked to my TE Probe and a 302 electronically compensated. They are very similar in response so I have been impressed how well the 302 works non-TE. I configured my panel so that the two varios would be independent in case I lost the TE system for some reason.
>
> As for the B Box, not sure anyone knows how to service one now. They have tubes that are likely rotted inside so I would not trust one. I have one on the self but have never used it.
>
> TT

The V7 has electronic compensation but,

Electronic TE compensation is only effective when the pitot tube and static sources are colocated
and the pneumatic lines to the instrument are approximately the same length.. The
best sensor to use is the combined pitot/static Prandtl tube. If problems are experienced
with the electronic TE compensation the most likely cause is the glider's static source. The
static source can be checked by plumbing the pneumatic tubes for electronic compensation
and then setting the TE: to 0%. In still air accelerate to approximately 160 km/h and slowly
reduce the speed. Observe the vario indicator. If the static source is good the vario should
immediately start to move to show a climb. If the needle firstly shows increased sink and
then moves to a climb, the static source of the glider is unsuitable and there is no way to
provide successful TE compensation electronically. The use of a dedicated and accurate finmounted
pitot/static source such as a Prandtl tube might help.


Richard
www.craggyaero.com