I think it's Ctrl and something, F1 or F2 I think. It may be in the documentation as reheat... The problem with the flaps canopy issues is that the aircraft may not have flaps (model not reality) so the designer has used the flaps key for something else. You may find the spoilers (/) useful for slowing down.
PS use of block capitals indicates shouting, please don't shout when I'm trying to help.
