AA Butterfly versus CNv LCD wind calculation

On Sunday, September 25, 2016 at 11:15:12 PM UTC-7, krasw wrote:
On Monday, 26 September 2016 04:25:15 UTC+3, Sean wrote:
LXNav S10 backup this spring for my new panel. I do not think the butterfly is worth the price...

SMF
7T

What are you backing up with S10? Don't you have mechanical vario?

No need for a mechanical backup the S10 has an internal backup battery for 3 hrs of use.

Richard
www.craggyaero.com

On Monday, 26 September 2016 17:24:02 UTC+3, Richard wrote:
On Sunday, September 25, 2016 at 11:15:12 PM UTC-7, krasw wrote:
On Monday, 26 September 2016 04:25:15 UTC+3, Sean wrote:
LXNav S10 backup this spring for my new panel. I do not think the butterfly is worth the price...

SMF
7T

What are you backing up with S10? Don't you have mechanical vario?

No need for a mechanical backup the S10 has an internal backup battery for 3 hrs of use.

Richard
www.craggyaero.com

Never heard of anyone not having a mechanical vario in glider.

On Monday, September 26, 2016 at 8:35:58 AM UTC-7, krasw wrote:
On Monday, 26 September 2016 17:24:02 UTC+3, Richard wrote:
On Sunday, September 25, 2016 at 11:15:12 PM UTC-7, krasw wrote:
On Monday, 26 September 2016 04:25:15 UTC+3, Sean wrote:
LXNav S10 backup this spring for my new panel. I do not think the butterfly is worth the price...

SMF
7T

What are you backing up with S10? Don't you have mechanical vario?

No need for a mechanical backup the S10 has an internal backup battery for 3 hrs of use.

Richard
www.craggyaero.com

Never heard of anyone not having a mechanical vario in glider.

I don't.

On Monday, September 26, 2016 at 9:41:21 AM UTC-6, jfitch wrote:
On Monday, September 26, 2016 at 8:35:58 AM UTC-7, krasw wrote:
On Monday, 26 September 2016 17:24:02 UTC+3, Richard wrote:
On Sunday, September 25, 2016 at 11:15:12 PM UTC-7, krasw wrote:
On Monday, 26 September 2016 04:25:15 UTC+3, Sean wrote:
LXNav S10 backup this spring for my new panel. I do not think the butterfly is worth the price...

SMF
7T

What are you backing up with S10? Don't you have mechanical vario?

No need for a mechanical backup the S10 has an internal backup battery for 3 hrs of use.

Richard
www.craggyaero.com

Never heard of anyone not having a mechanical vario in glider.

I don't.

I also do not have a mechanical vario...No need (at least for me) at all....In fact I am somewhat amazed folks are still buying them. Perhaps some clubs still buy them for simplicity or for some other reason, but I haven't had one in many years...

On Monday, September 26, 2016 at 8:35:58 AM UTC-7, krasw wrote:
On Monday, 26 September 2016 17:24:02 UTC+3, Richard wrote:
On Sunday, September 25, 2016 at 11:15:12 PM UTC-7, krasw wrote:
On Monday, 26 September 2016 04:25:15 UTC+3, Sean wrote:
LXNav S10 backup this spring for my new panel. I do not think the butterfly is worth the price...

SMF
7T

What are you backing up with S10? Don't you have mechanical vario?

No need for a mechanical backup the S10 has an internal backup battery for 3 hrs of use.

Richard
www.craggyaero.com

Never heard of anyone not having a mechanical vario in glider.

The two varios mentioned in the OP are all I have. The mechanical vario went away a long time ago, as did the mechanical compass.
Jim

I have a CNv-XC-digital as primary, LX S3 secondary. If they fail, I have the seat of my pants...

On Monday, September 26, 2016 at 11:35:58 AM UTC-4, krasw wrote:

Never heard of anyone not having a mechanical vario in glider.

I haven't had a mechanical in years. I have a B400 for backup (with AA back up battery pack) but it hasn't been switched on for more than a functional check in about 4 years (the last time I got out to the airport and discovered my batteries hadn't come with me).

Mechanical varios don't play well with modern pressure transducer type varios and should not share TE sources with them.

Evan Ludeman / T8

Mechanical varios don't play well with modern pressure transducer type varios and should not share TE sources with them.

Evan Ludeman / T8

A practice many seem to ignore. Do you think there is any advantage to using a fin mounted Prandtl tube versus fuselage pitot/static ports? Do you prefer mechanical or electronic TE? How do you "plumb" your CNvXC and B400?

On Monday, September 26, 2016 at 1:05:36 PM UTC-4, wrote:

Mechanical varios don't play well with modern pressure transducer type varios and should not share TE sources with them.

Evan Ludeman / T8

A practice many seem to ignore. Do you think there is any advantage to using a fin mounted Prandtl tube versus fuselage pitot/static ports? Do you prefer mechanical or electronic TE? How do you "plumb" your CNvXC and B400?

CNv works great on electronic compensation *provided* the pitot/static system is essentially perfect. The only practical, reliable way to get that is with a triple probe set up on the fin. Don't share the static with mechanical instruments.

I have a triple probe set up plus fuselage static ports.

I plumb all three triple probe sources to CNv, the TE also goes to B400. ASI uses triple probe pitot and fuselage static. CNv works well on the probe (an old venturi style probe) but even better on the pitot/static.

best,
Evan

The triple probe on the Stemme extends to about 3 feet in front of the
nose. That should be in pretty much undisturbed air.

On 9/26/2016 12:20 PM, Tango Eight wrote:
On Monday, September 26, 2016 at 1:05:36 PM UTC-4, wrote:
Mechanical varios don't play well with modern pressure transducer type varios and should not share TE sources with them.

Evan Ludeman / T8
A practice many seem to ignore. Do you think there is any advantage to using a fin mounted Prandtl tube versus fuselage pitot/static ports? Do you prefer mechanical or electronic TE? How do you "plumb" your CNvXC and B400?
CNv works great on electronic compensation *provided* the pitot/static system is essentially perfect. The only practical, reliable way to get that is with a triple probe set up on the fin. Don't share the static with mechanical instruments.

I have a triple probe set up plus fuselage static ports.

I plumb all three triple probe sources to CNv, the TE also goes to B400. ASI uses triple probe pitot and fuselage static. CNv works well on the probe (an old venturi style probe) but even better on the pitot/static.

best,
Evan

--
Dan, 5J