Just in case you wanted to see more flaps cut into H9 ARFs, here are flaps cut into a H9 T-34.

[link=http://www.rcuniverse.com/forum/m_1893157/anchors_1893157/mpage_1/key_t%252D34%252Cflaps/anchor/tm.htm#1893157]T-34 flap installation pictures[/link]

However, I still say the H9 P-51 does not need functioning flaps since it's almost a floater without them

quint