Originally Posted by
BMatthews
A plank style flying wing doesn't have either a fuselage or tail to use for stability so that's a red herring.
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Going back to the plank style wing for a moment. Due to the lack of a stabilizer the balance needs to be located quite strongly ahead of the 25% MAC of the wing. Just try to balance back behind that and it'll be like flying an arrow backwards.
No argument, only an addition: A symmetrically foiled plank is even resonably stable when balanced between 25% and 30% (28% recommended) due to down-pitching airfoil moment above 6 degrees AoA at least on thin airfoils (see
old thread).
And one could add to your last paragraph that the undercambered wing and tail airfoils develop much down-pitching moment so with a big stab the balance may be even at 100%.