This engine A/D was due around the end of August last year on the 522.
From what I read it is due on the 524 by August of this year.
I understand from the old Maint. folks at Thaisky that this was at a cost of 230,000. USD per airplane.
This only ordered the kit from RR and was to give them a 1 year extension for the work to be accomplished.
This may not be good or current information since almost 1 year has passed since they were dealing with this problem.
Perhaps some ground engineers can expand further on this.
I will try to look up the A/D number.