You should see that it is a copy of the Provost wing. Different aerofoil sections root to tip combined with washout designed to give good stall behaviour - didn't quite work as inboard leading edge stall strips were required. The Model T-6 doesn't have those stall strips and, in my opinion, is stretching FAR 23 requirements for uncommanded roll at the stall.See page 13 of http://airtourer.asn.au/airtourer/images/Newsletter/Newsletter%20153.pdf (from memory, not quite right - it is a 23012 not a 2312)