Henry VIII - that's the same basic requirements for the a/c I fly.
Someone posted the penalties for engine anti-ice and wing anti-ice and it's impact on altitude. At what temperatures or conditions does the A330 need wing or engine anti-ice in cruise? If it's -40C or colder the std temp at FL 350 is -53C. So it would have to be ISA + 14 to get warmer than -40C.
Are the posted(AF 447 thread) penalties of about -1300' correct for FL350 cruise?