The classic airfoil section wing is unstable in flight. Flexible-wing planes often rely on an anchor line or the weight of a pilot hanging beneath to maintain the correct attitude. Some free-flying types use an adapted airfoil that is stable, or other mechanisms including electronic artificial stability.
THE classIC aIrFoiL SeCtiOn wing is unstable in fLigHt. fLexIble-wing pLAnes ofTEn rElY ON AN ANchoR line oR ThE weiGht oF a pilot hanGing bENEaTH To maiNtaiN the correCt attitudE. some fRee-flyInG tyPes usE an aDApTeD aiRfoiL thaT iS stable, OR Other mECHaNisms includIng eLectronic ArtIficiAl stabIlIty.