An exemplary tiltrotor aircraft having a vertical takeoff and landing (VTOL) flight mode and a forward flight mode includes tiltable rotors located at forward boom ends, tiltable ducted fans located at wings aft of the forward boom ends, and aft rotors located on aft boom portions.

An energy management system (EMS) for an aircraft is provided. The aircraft may have one of a plurality of propulsion systems such as a parallel hybrid electric propulsion system, a parallel turbo electric propulsion system, an electric propulsion system, a turbo electric propulsion system and a turbo hybrid electric propulsion system. The EMS comprises redundant control paths for controlling safety critical operation. Each redundant control path is configured to independently determine whether to electrically isolate a line replaceable unit (LRU) from a high voltage DC link (HVDC link) based on status information from the LRU. The isolation is based on the independent determination. The HVDC link is used for propulsion. The number of the redundant control paths and components may be depending on the type of the propulsion system.

The invention relates to an aircraft comprising a drive system having a power unit, at least one drive battery, and at least one electric motor drawing electrical energy from the at least one drive battery, wherein the power unit comprises a two-cylinder reciprocating-piston engine having two cylinder-piston units in tandem arrangement and comprises at least one generator for generating electrical energy, wherein each cylinder-piston unit has a crankshaft, and wherein the crankshafts are mechanically coupled to each other, and wherein at least one crankshaft is mechanically connected to the at least one generator. The invention also relates to additional improvements of the aircraft and to an operating method.

An apparatus for determining a resource remaining datum of an electric aircraft is disclosed. The apparatus includes a processor and a memory communicatively connected to the processor. The memory contains instructions configuring the processor to receive aircraft data from at least a sensing device, wherein the at least a sensing device is configured to measure at least a parameter of a battery pack of the electric aircraft and generate aircraft data as a function of the at least a parameter of the battery pack of the electric aircraft. The memory contains instructions configuring the processor to determine a reserve energy as a function of a flight mode of the electric aircraft and determine a resource remaining datum as a function of the aircraft data and the reserve energy, wherein the resource remaining datum is related to the battery pack of the electric aircraft.

Systems and methods for distributing in an aircraft are provided. More particularly, in one embodiment, a system can include one or more gas turbine engines configured to provide propulsion and electrical power to an aircraft. The system can further include one or more electrical engines configured to provide propulsion for the aircraft. The system can include one or more first electrical power systems configured to provide power to the one or more electrical engines for one or more electrical power propulsion loads for the aircraft. The system can further include one or more second electrical power systems configured to provide power for one or more non-propulsion electrical power loads of the aircraft.

An example hybrid aircraft propulsion system includes one or more parallel propulsion units, each of the parallel propulsion units comprising: a first propulsor; a gas turbine engine configured to drive the first propulsor; and an electrical machine selectively configurable to: generate, for output via one or more electrical busses, electrical energy using mechanical energy derived from the first propulsor or the gas turbine engine; and drive the first propulsor using electrical energy received via the one or more electrical busses; and one or more series propulsion units, each of the series propulsion units comprising: a second propulsor; and an electrical machine selectively configurable to: generate, for output via the one or more electrical busses, electrical energy using mechanical energy derived from the second propulsor or the gas turbine engine; and drive the second propulsor using electrical energy received from one or more electrical busses.

An example hybrid aircraft propulsion system includes a plurality of electrical busses comprising a propulsion bus, a critical bus, and a non-critical bus; an electrical energy storage system coupled to each of the plurality of electrical busses; one or more power units configured to generate and output electrical energy via the propulsion bus; one or more electrical machines configured to drive respective propulsors using electrical energy received via the propulsion bus; one or more hotel loads configured to receive energy via the non-critical bus; and one or more critical loads configured to receive energy via the critical bus.

An example hybrid aircraft propulsion system includes one or more power units configured to output electrical energy onto one or more electrical busses; a plurality of propulsors; and a plurality of electrical machines, each respective electrical machine configured to drive a respective propulsor of the plurality of propulsors using electrical energy received from at least one of the one or more electrical busses.

An example hybrid aircraft propulsion system includes a plurality of power units configured to output electrical energy onto one or more electrical busses; one or more propulsors; and one or more electrical machines, each respective electrical machine configured to drive a respective propulsor of the one or more propulsors using electrical energy received from at least one of the one or more electrical busses.

In a hybrid flight vehicle, having multiple rotors attached to a frame, a gas turbine engine to drive the rotors; a generator connected to the gas engine to generate electric power, a battery store the electrical power generated by the generator. multiple first electric motors connected to the rotors to drive the same by the electric power supplied from the battery, a second electric motor connected to the gas turbine engine to motor the engine by the electric power supplied from the battery and a control unit to control flight, wherein the control unit stops supply of the fuel to the engine when a detected residual of the battery is equal to or greater than a predetermined value, and supplies electric power to the second electric motor to motor the engine when a detected temperature of the engine is equal to or higher than a predetermined temperature.