Aural Null Procedures

If you have followed the suggested order you should now have all the background information you need to start working on flying the Aural Null Procedures. But before we begin there are some things that are common for all aural searches whether procedure A, B or C.

  • Always disable the squelch on the radio you are using to listen for the transmitter. If you don't, some simple circuit is deciding what signals you listen to.
  • Insist on a sterile cockpit during critical phases of the search pattern. There is nothing worse than missing a signal change or having to redo a point because of unnecessary cockpit chatter.
  • It is not necessary to keep the volume on the monitor radio at a constant level. It is more important that it be kept at the highest comfortable setting. This will help you detect changes in the signal, reduce fatigue and avoid desensitizing your ears.
  • Always mark points on the way into the signal area. This will reduce the effects of receiver antenna asymmetries, if any. This will also direct any location errors due to reaction time towards the transmitter location. Your ears do a better job of detecting the onset of the signal than the disappearance of the signal.
  • Do not tune your receiver away from the beacon frequency in an attempt to reduce the diameter of the circle. Doing so without appropriate techniques result in a procedure which does depend on a circular area of equal signal strength. Since this is unlikely, failure to find the beacon is a very likely outcome.
You are now ready to move on to Aural Null Procedure A.