False glide slopes

[nick14]

Hi all,

I have been doing some research into false glide slopes. Most of the research and documents point towards false lobes which are at odd multiples of the actual path. So for a 3 degree approach there are catchable glides at 9 and 15 degrees. At 6 and 12 degrees there are null zones giving a failure flag.

Now this seems contradictory to what I have read about reports of people catching 6 degree slopes.

Does anyone know what the automatics of a transport jet will capture, is it the 6 or 9 degree slope and what are the indications?

Thanks