Justbelowcap,
I'd tend to agree with your trainer. If icing conditions are present below acceleration altitude, e.g. OAT on ground 4 deg. C, clouds bkn 200 ft., you would (in most aircraft - check your AFM/FCOM) depart with ice protection switched ON.
...or you might have a failure at V1, and then have to both fly the aircraft, complete memory items, select anti-ice on and bug the new speeds - all below acceleration altitude
- doesn't sound like the fastest way to a long and happy life
So yes, the anti-ice should be ON (again, AFM depending...) and the appropriate performnce penalties and speeds should be applied.
...eeerrr, methinks...
Brgds,
Empty