Originally Posted by theresalwaysone
Why do you need to test them on the ground apart from do they switch on and remove flags and thats subject to range so unreliable-- you test then before use in the air--thats were they are designed to work. A corrrectly identified morse signal is the only guaranteed indication on the ground if the aid is within range. Directional signals received on the ground are subject to errors.
Accuracy? +/- 4 degrees for a ground check? -/+ 6 degrees for airborne check? Could find yourself in some nasty situations if your VOR is indicating a bearing error of 20 degrees at 30 miles.
Think you'll find it a requirement to test your VOR's before using them as IFR nav aids every 30 days (FAA that is, don't know about JAA land).
You can climb off up into the soup without knowing the accuracy or indeed if the VOR's work but I sure wont.