Maybe someone will be able to explain to me how come:
* Aeroplan is able to let me "buy" a flight on business class from Turkish. So it sees it...
* Won't let me upgrade that same exact flight with my existing ticket using SAUA. Says no seat available...

Plenty of availability:
C4 D4 K9 J4 I4 R4 Y9 B9 M9 H9 S9 E9 Q9 T9 L9 V9 P9 W9 X9 N9 G0

I am puzzled. Is TK systematically blocking Aeroplan requests for upgrades?