Melchior

> 
> Seems that there are two bugs that make the bo105 ASI show
> positive speeds when flying backwards:
> 
> 1. YASim delivers a positive "/velocities/airspeed-kt" on backward
>    flight.
> 
> 2. Systems/pitot.cxx wouldn't handle negative values correctly,
>    anyway, as it squares the speed without checking for negatives.
> 
> The second is easy to fix, but I have no idea about the first.
> 

A pitot tube compares the pressure along the _forward_ axis of the tube,
caused by forward flight, with the static pressure. I don't think such a
device will measure the speed backwards. It is only accurate when the
airflow is co-axial with the tube.

You need some other device to measure backward velocity. In the only case
with which I am familiar (Westland Wessex HAS1 and 3) there was a Doppler
radar. Used to get into difficulties over calm seas when attempting an
auto-hover IIRC. 

Vivian 



-------------------------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
_______________________________________________
Flightgear-devel mailing list
Flightgear-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/flightgear-devel

Reply via email to