An aircraft includes at least one propulsion system. The at least one propulsion system includes a propulsor, an engine, and an electrical assembly. The engine is coupled to the propulsor and configured to drive rotation of the propulsor. The electrical assembly includes an electric motor, a battery, an external power assembly, and an electrical distribution system. The electric motor is coupled to the propulsor and configured to drive rotation of the propulsor. The external power assembly includes a first connector and a second connector. The first connector and the second connector are positionable at an exterior of the aircraft. The electrical distribution system electrically connects the electric motor, the battery, the first connector, and the second connector.

An aircraft assist system described herein includes an aircraft coupling counterpart attached to a strut of a landing gear of an aircraft, and an assist vehicle. The assist vehicle includes a frame, ground-engaging wheels mounted to the frame, a power source for driving one or more of the ground-engaging wheels, and a vehicle coupling counterpart for engagement with the aircraft coupling counterpart. The aircraft coupling counterpart and the vehicle coupling counterpart define a swivel connection for transferring a propulsive force from the takeoff assist vehicle to the aircraft. The aircraft coupling counterpart is disengageable from the vehicle coupling counterpart by upward movement of the aircraft coupling counterpart relative to the vehicle coupling counterpart.

A system for ground power supply of aircraft includes at least one mobile transformer unit having a first vehicle chassis and a voltage transformer mounted on the first vehicle chassis; at least two energy stores which can be alternately connected to an input of the voltage transformer in order to supply the voltage transformer with electric energy; and a supply cable for ground power supply of one of the aircraft. The supply cable is configured to be connected to an output of the voltage transformer. Each of the at least two energy stores is part of one of at least two mobile storage units each including a second vehicle chassis. The first vehicle chassis of the transformer unit and each of the second vehicle chassis of the at least two mobile storage units are moveable on the ground independently on each other.