The US bandplan in the scanner are set to AM in the 138-144MHz range using a 12,5KHz step size. If you change to United Kingdom bandplan it will do FM but using a 6,25KHz stepsize, half the speed.How do I change to this FM?
The first paragraph states that the military aircraft uses AM and gives the possible frequencies, including the range he asked about.
"Aircraft communications will be in AM mode while satellite communications in this band will be in NFM mode. Military aircraft sometimes also use the Civilian Aircraft Band (108 to 137 MHz), especially when flying into a civilian airport. They may also be heard in the 137 to 144 MHz..."