in such a case, things i would do: adz aircraft to squawk ident...relay message thru other aircraft...via selcal...adz his operator or handler if there's one in my country....recheck flight plan...if he's not flying where he's supposed to, i might consider notifying airforce people...but then we don't have aircraft or whatever to intercept possible terrorist attack anyway so i think my job ends where my super's headache begins.
