What is an XX30?

[Martymccasland]

Was doing some instrument currency this morning and heard (along with my safety pilot) ATC say, "XX30 (Callsign) climb and maintain 123...", "XX30 (Callsign) turn right 123", etc..

Neither I or my friend have ever heard of an "XX30". 'Googled 5-6 different ways and only found trans-oceanic reporting lingo as the closest thing to a plane called an XX30. Since we were flying in Little Rock, AR, I doubt it was any sort of trans-oceanic discussion.

Even went to my kneepad and double checked since I wrote it down upon hearing it. Yep, "XX30" is definitely what they were saying.

Any clue?

 

[Jim Logajan]

Did they say "xray xray three zero" or "ex ex three zero"?

 

[Jim Logajan]

Furthermore, they wouldn't say "three zero", but "thirty".

Ex: "Ex Ex thirty 1-2-3 alpha bravo climb and maintain..."

If a fricative like "ess" was misheard (or mispronounced) as "ex", then "ess ex thirty" (SX-30) would be a Swearingen SX-300: http://flightaware.com/live/aircrafttype/SX30

But if you heard correctly, my attempt at a resolution is of course void.