Actually, if all that you are using the polar for is to plug
the curve into your B50 (or equivalent vario that delivers
speed to fly cues) then you don't need to calibrate much at
all.

If you use the data output from that vario (ie the data the
vario is using itself to calculate speed to fly) to
calculate the polar then it is effectively a closed system
of variables ie the data used to make the polar is the same
data that the instrument itself is using.  You can rapidly
and easily achieve a suitable polar with little fuss.

The only problem is that your polar will be unique for your
aircraft / vario combination and is not relevant to any
other glider or vario because nothing is calibrated.  All
calibration does is make apples comparable to other apples
on the same apple scale - in this case a calibrated polar
would be roughly applicable to other LS-1F's.  Hence one of
my original comments - what do you want to use the polar
for?  

For some good references research every performance test
done by Dick Johnson in the USA (they are on the web in PDF
and should have a link from the SSA site).  Also acquire a
copy of Fundamentals of Sailplane Design by Fred Thomas, it
has some chapters in there on flight testing.

 

> Measuring the polar isn't trivial. You need to calibrate
> the ASI and  altimeter, use the vibrator to eliminate
> sticktion, do a position  error measurement, measure OAT
> reasonably accurately and then do an  error analysis to
> get the size of the error bars. The find still air  and do
> enough runs to get enough measurements. Then look at the 
> results and repeat the points where there was lots of
> scatter or that  look dubious.
> 
> All this is quite tedious which is why it isn't done very
> often.
> 
> Mike
> Borgelt Instruments - manufacturers of quality soaring
> instruments phone Int'l + 61 746 355784
> fax   Int'l + 61 746 358796
> cellphone Int'l + 61 428 355784
>            Int'l + 61 429 355784
> email:   [EMAIL PROTECTED]
> website: www.borgeltinstruments.com
> _______________________________________________
> Aus-soaring mailing list
> [email protected]
> To check or change subscription details, visit:
> http://lists.internode.on.net/mailman/listinfo/aus-soaring
_______________________________________________
Aus-soaring mailing list
[email protected]
To check or change subscription details, visit:
http://lists.internode.on.net/mailman/listinfo/aus-soaring

Reply via email to