Certainly not an expert here, but I'll give this one a try: Most aircraft frequencies you/we listen to are broadcast over VHF (Very High Frequencies). These aircraft mainly are in the range of 108-137 MHz. Air Traffic Controllers also offer a simulcast transmission which is transmitted on a UHF (Ultra-High Frequency), usually in the range of 225-420 MHz. This range is mainly used by the Military aircraft, while commercial and general aviation pilots use the VHF. If using the UHF frequencies, you would only hear the controller side of the conversation, and miss all the chatter of the other aircraft calling on the VHF frequency. The VHF frequencies are called “Victor”, and UHF frequencies are known as “Uniform”. Astro 95 was given the VHF frequency of 125.35 and was requesting the “Uniform” (UHF equivalent from the controller) which is 354.1. I would assume it was to focus on what they were trying to do in the cockpit, and not be disturbed by all the chatter of the news helicopters flying in the area who were also talking with the controller on the VHF frequency. Most scanner listeners out there use the VHF mode to pick up both sides of the conversation. Like I said earlier, the military/government are the main users of the aircraft UHF frequencies. Perhaps the easiest way to remember it is military=uniforms, and UHF is shortened as “Uniform”. Hope that helped a little.