Some strange unknowns from today:
520273 - callsign "HONDA 28", 153 messages, altitude 18000 to 20000ft, 14:56Z-15:15Z
520274 - callsign "HONDA 29", 79 messages, altitude 18000, 15:08Z-15:23Z
520276 - callsign "FU 3D 1", 97 messages, altitude 18000, 14:44Z-15:24Z
52027A - callsign "WHACK 27", 129 messages, altitude 18000, 15:02Z-15:17Z
As far as I know, the block 52xxxx is not allocated.
Liviu