Fléchir belong to the 2nd
group. Fléchir is a common french verb.
Fléchir is conjugated the same way that verbs that end in : -ir
Fléchir is conjugated with auxiliary avoir
Fléchir verb is
direct transitive, intransitive.
French verb fléchir can be conjugated in the reflexive form: Se fléchir
verb is a direct transitive verb, so passive voice can be used.