Bohli Compass

use of compass for cloud flying.
I have read here that XCSoar has this artifical horizon capability.
Yet the manual says nothing about it. Is this one of those hidden features
that many pieces of software have?
Does anyone know how to access it?

The XCSoar horizon can be selected in an Info Box.

Press and hold on the Info Box of your choice, select Switch InfoBox,
find and select Attitude Indicator, select Close. The selected Info Box
will be labeled, "Horizon". I've tried it and I found it of no use.

On 10/31/2015 8:58 AM, Soartech wrote:
use of compass for cloud flying.
I have read here that XCSoar has this artifical horizon capability.
Yet the manual says nothing about it. Is this one of those hidden features
that many pieces of software have?
Does anyone know how to access it?


--
Dan, 5J

On Thursday, October 29, 2015 at 6:03:35 PM UTC-7, wrote:
What is a reasonable value of a Bohli compass? does not appear to have ever been installed
Does it still have value?

r/Jim

If you want to contact me privately (tab on right side of message, I would be willing to speak to you about purchasing.

lauantai 31. lokakuuta 2015 16.16.26 UTC+2 Dan Marotta kirjoitti:
I truly don't know what it's worth, if anything.



I've read that, properly set up, it can be used to fly in clouds.*
I've also read that it was banned in contests in the US for just
that reason.* It would be fun to have as a toy, just like that J-8
attitude indicator that I've had in a box for close to 40 years.

I've flown with Bohli compass and it's main use is same as directional gyro's. When IMC (or VMC, of course) you can straighten your turn to correct heading right away if compass is tilted correctly. With normal Airpath compass procedure inside cloud is to straighten to any direction, wait 15-30 sec to get compass reading, then calculate how many seconds to make 30sec (or 1 min) standard rate turn to correct heading. This takes easily couple of minutes in all. These days any modern GPS gives you track reading at 1 hZ, which makes Bohli compass totally obsolete. You can not fly IMC with only Bohli compass, that has to be some misunderstanding.

At 19:04 31 October 2015, krasw wrote:
lauantai 31. lokakuuta 2015 16.16.26 UTC+2 Dan Marotta kirjoitti:
I truly don't know what it's worth, if anything.
=20
=20
=20
I've read that, properly set up, it can be used to fly in
clouds.=A0
I've also read that it was banned in contests in the US for just
that reason.=A0 It would be fun to have as a toy, just like that
J-8
attitude indicator that I've had in a box for close to 40 years.

I've flown with Bohli compass and it's main use is same as directional
gyro=
's. When IMC (or VMC, of course) you can straighten your turn to correct
he=
ading right away if compass is tilted correctly. With normal Airpath
compas=
s procedure inside cloud is to straighten to any direction, wait 15-30
sec
=
to get compass reading, then calculate how many seconds to make 30sec (or
1=
min) standard rate turn to correct heading. This takes easily couple of
mi=
nutes in all. These days any modern GPS gives you track reading at 1 hZ,
wh=
ich makes Bohli compass totally obsolete. You can not fly IMC with only
Boh=
li compass, that has to be some misunderstanding.


You can fly IMC (ie climb in thermals in cloud and straighten up on a
heading) on just a Bohli, ASI and slip ball, I have done so in the past to
prove the point. It is very high workload and taxed me near to the limit
and I have far more cloud flying experience in gliders than most pilots.

sunnuntai 1. marraskuuta 2015 9.00.07 UTC+2 Chris Rollings kirjoitti:
You can fly IMC (ie climb in thermals in cloud and straighten up on a
heading) on just a Bohli, ASI and slip ball, I have done so in the past to
prove the point. It is very high workload and taxed me near to the limit
and I have far more cloud flying experience in gliders than most pilots.

Then you could do it also by looking at gps track instead of compass. I have only enough IMC experience to not try that kind of stunt.

At 08:13 01 November 2015, krasw wrote:
sunnuntai 1. marraskuuta 2015 9.00.07 UTC+2 Chris Rollings kirjoitti:
You can fly IMC (ie climb in thermals in cloud and straighten up on a
heading) on just a Bohli, ASI and slip ball, I have done so in the past
to
prove the point. It is very high workload and taxed me near to the
limit
and I have far more cloud flying experience in gliders than most
pilots.

Then you could do it also by looking at gps track instead of compass. I
have only enough IMC experience to not try that kind of stunt.


Actually, that's not the case, a Bohli gives (by inference) angle of bank
information as well as heading. If the indicator is tracking
concentrically with the instrument then the instrument is tilted to the
aircraft's angle of bank. If it isn't the you change the angle of tilt on
the compass until it is.

So basically there is no reason to ban them from competition. As myself and others have pointed out, a smart phone or tablet also is capable of acting as a Horizon with free apps available.

On Saturday, October 31, 2015 at 12:04:41 PM UTC-7, krasw wrote:

I've flown with Bohli compass and it's main use is same as directional gyro's. When IMC (or VMC, of course) you can straighten your turn to correct heading right away if compass is tilted correctly. With normal Airpath compass procedure inside cloud is to straighten to any direction, wait 15-30 sec to get compass reading, then calculate how many seconds to make 30sec (or 1 min) standard rate turn to correct heading. This takes easily couple of minutes in all. These days any modern GPS gives you track reading at 1 hZ, which makes Bohli compass totally obsolete. You can not fly IMC with only Bohli compass, that has to be some misunderstanding.