Hi H1ro,
If you look at FCOM, Performance, Maximum Take Off, you will see tables of maximum N1 versus Temperature and Pressure Altitude. There is no correction to N1 for Engine Anti ice until ISA + 30 or temp above "corner point". (Probably due to EGT limit)
Are you noticing the reduction in N1 during Flex Take Offs with an assumed temperature above ISA + 30?
Last edited by rudderrudderrat; 23rd October 2013 at 09:20.