Neither are capable of milair out of the box. I don't know of a fix for the 2051, but Win96 can open up the freqs for the PRO-2096. Problem is, neither scanner is set up for milair, so the sensitivity is going to be all over the place. Some folks find the 2096 works OK on milair, others find it's deaf as a post; and that's not an indication of a defective unit.
That being said, the 138-144 mhz band, where many air national guard units can be found, should be quite useable. I'm fairly sure you can change the mode to AM on the 2096 (that's the common mode here), but not sure about the 2051. 73s Mike