It could be worse and giving something like this back:
Make sure your are pining in the right direction. Having your sound man report the nearest contact gives you a bearing to listen too, but usually if you hear the propellers your good to go ... ping.
Also, it takes ages for the distance to show up in the message box to appear (if at all), unless you manually push the "Send Range to TDC". This can be done before the ping actually returned. You could just ping->send repeatedly in quick succession.