View Single Post
  #8  
Old January 27th 15, 03:23 PM posted to rec.aviation.soaring
Richard[_9_]
external usenet poster
 
Posts: 551
Default Non-TE probe compensation

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