A twin-engine aircraft power and propulsion system including first and second propulsive gas turbine engines, each having combustion equipment and a first and second spool; first, second, third, and fourth electrical power generation sub-systems including electric machines respectively mechanically coupled with the first spool of the first propulsive gas turbine engine, the second spool of the first propulsive gas turbine engine, the first spool of the second propulsive gas turbine engine, and the second spool of the second propulsive gas turbine engine; and first, second, third, and fourth power channels respectively connected with distribution sides of the first electric machine, second electric machine, third electric machine, and fourth electric machine.