A system and method are provided that direct a real time global view with images of an aircraft's entire exterior environment from an external monitoring system located on an aircraft equipped with landing gear wheel-mounted electric taxi drive systems powering ground travel to an integrated head-up display worn by a pilot driving the aircraft with the electric taxi drive systems within an airport ramp area. The real time global view and images produced by the monitoring system are communicated to the integrated head-up display in the form of an actual picture of the ramp area environment exterior to the aircraft viewable by the pilot with the head-up display in real time as the pilot maneuvers the aircraft within the ramp area with the electric taxi systems. The pilot can change the images viewed in the head-up display by changing head position.

In one aspect the present subject matter is directed to a gas-electric propulsion system for an aircraft. The system may include a turbofan jet engine, an electric powered boundary layer ingestion fan that is coupled to a fuselage portion of the aircraft aft of the turbofan jet engine, and an electric generator that is electronically coupled to the turbofan jet engine and to the boundary layer ingestion fan. The electric generator converts rotational energy from the turbofan jet engine to electrical energy and provides at least a portion of the electrical energy to the boundary layer ingestion fan. In another aspect of the present subject matter, a method for propelling an aircraft via the gas-electric propulsion system is disclosed.

An aircraft with the capability of taxiing with main engines off uses the energy stored in a mechanical flywheel to power a propulsor(s) providing taxiing thrust. The flywheel can store energy generated by the propulsor operating as a wind turbine and/or by a power turbine in fluid coupling with the exhaust of a gas turbine engine and/or an expansion turbine operating with bleed and/or APU air.

One variation of a tram system includes: a chassis; a latch configured to selectively engage a latch receiver mounted to an aircraft; an alignment feature adjacent the latch and configured to engage an alignment receiver mounted to the aircraft and to communicate acceleration and braking forces from the chassis into the aircraft; an optical sensor facing upwardly from the chassis; a drivetrain configured to accelerate and decelerate the chassis along a runway; and a controller configured to detect an optical fiducial arranged on the aircraft in optical images recorded by the optical sensor adjust a speed of the drivetrain to longitudinally align the alignment feature with the alignment receiver based on positions of the optical fiducial detected in the optical images, trigger the latch to engage the latch receiver once the aircraft has descended onto the chassis, and trigger the drivetrain to actively decelerate the chassis during a landing routine.

In one aspect the present subject matter is directed to a gas-electric propulsion system for an aircraft. The system may include a turbofan jet engine, an electric powered boundary layer ingestion fan that is coupled to a fuselage portion of the aircraft aft of the turbofan jet engine, and an electric generator that is electronically coupled to the turbofan jet engine and to the boundary layer ingestion fan. The electric generator converts rotational energy from the turbofan jet engine to electrical energy and provides at least a portion of the electrical energy to the boundary layer ingestion fan. In another aspect of the present subject matter, a method for propelling an aircraft via the gas-electric propulsion system is disclosed.

A method is provided for operating a hybrid-electric propulsion system of an aircraft. The hybrid-electric propulsion system includes a gas turbine engine having a high pressure system, a low pressure system, an electric machine coupled to at least one of the high pressure system or low pressure system, and an energy storage unit. The method includes operating the electric machine as an electric generator to charge the energy storage unit during a flight operation of the aircraft; switching the gas turbine engine to an electric operating mode during or after a landing operation of the aircraft; driving a system of the gas turbine engine using power from the energy storage unit while in the electric operating mode to provide or assist with providing ground operations the aircraft.

A heat radiator for an aircraft, which cools a heat source installed in the aircraft, includes a heat radiating part in which a contact surface comes into contact with a main flow, the contact surface being formed with a concave portion or a convex portion in which a surface thereof directed upstream in a flow direction of the main flow is curved in a plan view.

A system and method are provided that direct a real time global view with images of an aircraft's entire exterior environment from an external monitoring system located on an aircraft equipped with landing gear wheel-mounted electric taxi drive systems powering ground travel to an integrated head-up display worn by a pilot driving the aircraft with the electric taxi drive systems within an airport ramp area. The real time global view and images produced by the monitoring system are communicated to the integrated head-up display in the form of an actual picture of the ramp area environment exterior to the aircraft viewable by the pilot with the head-up display in real time as the pilot maneuvers the aircraft within the ramp area with the electric taxi systems. The pilot can change the images viewed in the head-up display by changing head position.

One variation of a tram system includes: a chassis; a latch configured to selectively engage a latch receiver mounted to an aircraft; an alignment feature adjacent the latch and configured to engage an alignment receiver mounted to the aircraft and to communicate acceleration and braking forces from the chassis into the aircraft; an optical sensor facing upwardly from the chassis; a drivetrain configured to accelerate and decelerate the chassis along a runway; and a controller configured to detect an optical fiducial arranged on the aircraft in optical images recorded by the optical sensor adjust a speed of the drivetrain to longitudinally align the alignment feature with the alignment receiver based on positions of the optical fiducial detected in the optical images, trigger the latch to engage the latch receiver once the aircraft has descended onto the chassis, and trigger the drivetrain to actively decelerate the chassis during a landing routine.

One variation of a tram system includes: a chassis; a latch configured to selectively engage a latch receiver mounted to an aircraft; an alignment feature adjacent the latch and configured to engage an alignment receiver mounted to the aircraft and to communicate acceleration and braking forces from the chassis into the aircraft; an optical sensor facing upwardly from the chassis; a drivetrain configured to accelerate and decelerate the chassis along a runway; and a controller configured to detect an optical fiducial arranged on the aircraft in optical images recorded by the optical sensor adjust a speed of the drivetrain to longitudinally align the alignment feature with the alignment receiver based on positions of the optical fiducial detected in the optical images, trigger the latch to engage the latch receiver once the aircraft has descended onto the chassis, and trigger the drivetrain to actively decelerate the chassis during a landing routine.