Call Sign question:

[Rick1959]

Guys,
While monitoring 11.175 this evening I monitored an aircraft using the call sign "Aircraft 4636" which I am guessing may be a tail number. A/C was hailing "any ground station" as opposed to Mainsail as well. MAC did respond with a radio check. Thought the call sign was bit unusual and the "any ground station" transmission instead of "Mainsail - Mainsail". Comments? Thanks in advance.
Rick

 

[K9WG]

11.175 is used by all the military branches, and I believe "Mailsail" is primarily a USAF comm. I have even heard USN nuke subs communicating on 11.175

 

[Hooligan]

I don't think "any ground station" vs. MAINSAIL is all that unusual, but what you probably heard was an aircraft's crew chief or someone other than cockpit-crew getting on the radio. These guys don't always know the mission callsign for the aircraft & aren't often familiar with HF procedures. Likewise, long after Military Airlift Command disappeared & Air Mobility Command with the REACH callsigns manifested itself, I'd occasionally hear guys calling for a radio check, ID'ing as MAC #####. Sometimes, they'd even do it on a long-obsolete channel like 11246 (old MacDill Global channel). Best all is hearing "MAC #####" calling "Scott Global" on 11182 -- MAC, Scott Global & 11182 having been phased-out a decade+ ago!

Long ago, I heard "Air Force Two" asking for an HF radio check using really poor procedure & at a time when I knew the VP was at his residence. Turned out it was a crew chief for one of the old 89th AW VC-9s playing around while the actual communications systems operator was taking a leak while pre-flighting the plane for a non-AF2 mission.