BigEndBob;
Are they heated vanes? If so they would not be powered on the ground.
I don't see any point in frequently testing them on the ground other than to verify that the wiring is intact and the horn is functional (usually the same horn is used for the gear warning). The maintenance dept. likely does that type of check during the annual inspection (with the aircraft on jacks). They are not very accurate devices. Testing via an actual stall would be a better indication of correct function.
Last edited by Tree; 22nd Apr 2007 at 19:48.