Various implementations described herein are directed to an aircraft having a multi-engine configuration with multiple engines. The aircraft may have a flight control system coupled to the multiple engines with a multi-engine interface. The flight control system may be configured to shutdown at least one engine of the multiple engines during reduced-engine operation by continuously calculating altitude for the reduced-engine operation based on one or more of an aircraft descent rate of the aircraft and an engine restart time of the at least one engine.

A motor mounted on a drone includes a rotor including a propeller mounting portion with a propeller detachably attached, the rotor being rotatable about a central axis, a stator radially facing the rotor with a gap therebetween, and an auto-balancer capable of automatically correcting dynamic balance of the rotor.

A motor mounted on a drone includes a rotor including a propeller mounting portion with a propeller detachably attached, the rotor being rotatable about a central axis, a stator radially facing the rotor with a gap therebetween, and an auto-balancer capable of automatically correcting dynamic balance of the rotor.

An aircraft drive shaft including an outer shaft having a first diameter configured to couple a first gearbox and a second gearbox to provide power transfer between the two gearboxes, an inner shaft concentric with the outer shaft and having a second diameter configured to provide structural support to the outer shaft, a gap defined between an outer peripheral surface of the inner shaft and an inner peripheral surface of the outer shaft, wherein the gap is sized according to a ballistic projectile cross-section size that the aircraft is considered to encounter on an upcoming mission, and a sleeve located at least at first end of the outer shaft connecting the outer shaft to the inner shaft.

An aircraft drive shaft including an outer shaft having a first diameter configured to couple a first gearbox and a second gearbox to provide power transfer between the two gearboxes, an inner shaft concentric with the outer shaft and having a second diameter configured to provide structural support to the outer shaft, a gap defined between an outer peripheral surface of the inner shaft and an inner peripheral surface of the outer shaft, wherein the gap is sized according to a ballistic projectile cross-section size that the aircraft is considered to encounter on an upcoming mission, and a sleeve located at least at first end of the outer shaft connecting the outer shaft to the inner shaft.

Tail rotor control system is described for helicopters. A pedal position sensor operable by a pilot yields greater tail rotor RPM relative to the main rotor RPM, giving the pilot increased control over the vehicle. This proves especially useful in certain situations, such as high altitude, where increasing tail rotor speed from main rotor speed can give a pilot increased maneuverability and stability.

Tail rotor control system is described for helicopters. A pedal position sensor operable by a pilot yields greater tail rotor RPM relative to the main rotor RPM, giving the pilot increased control over the vehicle. This proves especially useful in certain situations, such as high altitude, where increasing tail rotor speed from main rotor speed can give a pilot increased maneuverability and stability.

The turboshaft engine for a rotorcraft includes a low pressure spool having a low pressure compressor and a low pressure turbine section, and a high pressure spool having a high pressure compressor and a high pressure turbine section. The spools are independently rotatable relative to one another. The low pressure compressor section includes a mixed flow rotor. A set of variable guide vanes (VGVs) are discposed upstream of each of the low pressure and high pressure compressors, the VGVs being configured to be independently operable relative to one another.

The turboshaft engine for a rotorcraft includes a low pressure spool having a low pressure compressor and a low pressure turbine section, and a high pressure spool having a high pressure compressor and a high pressure turbine section. The spools are independently rotatable relative to one another. The low pressure compressor section includes a mixed flow rotor. A set of variable guide vanes (VGVs) are discposed upstream of each of the low pressure and high pressure compressors, the VGVs being configured to be independently operable relative to one another.

An aircraft includes first units each including a first sensor, a rotary wing, a driver, and a first drive controller. The first drive controller is configured to generate a drive signal of the rotary wing on the basis of a flying route of the aircraft and a control law based on a flying state detected by the first sensor, and output the drive signal to the driver configured to drive the rotary wing. The control laws of the respective first drive controllers are equal to each other between the first units. The first drive controllers are each configured to generate the drive signals that correspond to all of the first units. The drivers are each configured to drive the corresponding rotary wing on the basis of corresponding one of the drive signals that correspond to all of the first units and that are generated by the first drive controllers.