Last year I had 2 aircraft on my freq both requesting the same level, both were 2 of the big US 3, they had the exact same flight number. I advised them both of similar callsign on freq when the second aircraft checked in. The following occured:
"ABC123 request climb FL370"
He was approaching my boundary with the next FIR so I had to tell him to standby while this was coordinated.
A minute or so later:
"XYZ123 request climb FL370"
No traffic or restrictions to effect
Me: "XYZ123 control, climb FL370"
"ABC123 climbing FL370"
Me: "ABC123 negative negative, maintain FL350, previous clearance was for another aircraft"
The only reason I spotted this was because he used his callsign.
Now earlier this year, another of the US big 3:
"ABC456 request climb FL370"
Me:"ABC456 climb FL370
"Here we go"
Last edited by Una Due Tfc; 19th Aug 2015 at 01:40.