On Fitting groups whose proper subgroups are solvable

This work is a continuation of [A. O. Asar, On infinitely generated groups whose proper subgroups are solvable,  J. Algebra, 399 (2014) 870-886.], where it was shown that a perfect infinitely generated group whose proper subgroups are solvable and in whose homomorphic images normal closures of finitely generated subgroups are residually nilpotent is a Fitting $p$-group for a prime $p$. Thus this work is a study of a Fitting $p$-group whose proper subgroups are solvable. New characterizations and some sufficient conditions for the solvability of such a group are obtained.