Somewhere in the late 90', we completed an overhaul on a DR315 with my boss in our samll mtx shop.
At that stage, the plane was 11.000 hours + and in good shape.
Probably built in the mid 70'.
I saw it last summer, still showing good, still flying student pilots around for the airclub some 20+...
My last project was to refurbish a beautifyfull GY 20 MiniCab (the ancester of the Cavalier). But my new job sent me away from home on a non commuting roster.
I have flown a 1953 D9 without the current twist few decades ago. She was a delight for her 26,5 hp. But very very demonstrative when it...
Shame on me, Simflyer : you are right.
The D9 and 11 series do use 23012.
The 100 200 300 400 500 series use 23013,5 (all have the same dimension wing, with different spars/ flaps, air brakes settings)
The D18/19/ 20 and DC21 use 43013,5
The Jodel D11 serie (as most of the subsequent Robin serie 100 200 300 and 400) use a NACA "23013,5"
Jean Delmontez, the designer tried to squeeze the biggest spar in the wing with out the penalty of the more draggy 23015. So he used a 13,5% thickness. (Some of the early Robin 400 without wing...