A Part 91 operator is only permitted to provide flights for non-commercial purposes, and works under regulations defined by the US Federal Aviation Administration (FAA) for non-commercial operations.

A Part 91 operator is only permitted to provide flights for non-commercial purposes, and works under regulations defined by the US Federal Aviation Administration (FAA) for non-commercial operations. This means that Part 91 operators cannot under any circumstances receive compensation or even reimbursement for flights conducted.

Part 91 regulations are a set of defined conditions under which the aircraft must operate. These include required landing distances, safe weather requirements, in addition to pilot training. Part 91 operators are also insured under a more limited set of regulations than Part 135 operators, and so have a reduced liability.