I have a Boeing mentality and was therefore surprised when Airbus instructors advised us that there isn’t a time limit for FLX, they have interpreted the regulation that Takeoff and Go-Around thrust must have a time limit. FLX thrust isn’t written in the regulation, therefore it doesn’t apply and isn’t listed as a restriction in the FCOM!
And yet, if you use the Airbus LPC to calculate FLX, the performance is based upon completing the takeoff within 10 minutes!
So it’s as clear as mud!
Mutt