A flight control system for controlling an aircraft during a variable engine thrust takeoff operation operative to perform a method including calculating a calculated acceleration in response to a takeoff distance and a selection of a variable engine thrust takeoff mode, generating an initial thrust control signal in response to the calculated acceleration, controlling a thrust of an aircraft engine in response to the initial thrust control signal, measuring a measured acceleration of the aircraft, generating an updated thrust control signal in response to a difference between the calculated acceleration and the measured acceleration, and controlling the thrust of the aircraft engine in response to the updated thrust control signal.

A control system (50) for an electro-hydraulic servo-actuator (26) envisages: a controller (55), to generate a control current (I.sub.c), designed to control actuation of the electro-hydraulic servo-actuator (26), implementing a position control loop based on a position error (e.sub.p), the position error (e.sub.p) being a difference between a reference position (Pos.sub.ref) and a measured position (Pos.sub.meas) of the electro-hydraulic servo-actuator (26); and a limitation stage (58), coupled to the controller (55) to provide a limitation of the actuator speed of the electro-hydraulic servo-actuator (26); the limitation stage (58) limits a rate of change of a driving current (I.sub.d) to be supplied to the electro-hydraulic servo-actuator (26), in order to limit the actuator speed.

An airplane has main propulsion engines and a first fuel supply for the main propulsion engines. The airplane further has an auxiliary propulsion engine and a second fuel supply for the auxiliary propulsion engine, this second fuel supply being separate from the first fuel supply. The auxiliary propulsion engine can be switched on independently from the main propulsion engines. Such airplane has increased safety, since it will be possible to maintain flight, particularly when at high altitude, even if all main propulsion engines have failed.

An example method for installing optical sensors for a fuel level measurement system includes mounting a plurality of fittings through a wall of a fuel tank, positioning a plurality of optical sensors within the plurality of fittings and a respective optical sensor includes a first pressure sensing end inserted through the fitting and internally into the fuel tank and a second end extending externally from the fuel tank, and mounting an optical fiber bundle external to the fuel tank. The optical fiber bundle has an optical fiber connected to each of the plurality of optical sensors for guiding light to each of the plurality of optical sensors.

According to some embodiments, system and methods are provided, comprising receiving one or more mission objectives for an aircraft mission, and condition data at a mission execution module; generating, via the mission execution module, a mission plan executable to address at least one of the one or more mission objectives via manipulation of a power-thermal management system (PTMS); receiving the generated mission plan at the PTMS directly from the mission execution module; and automatically executing the generated mission plan to operate an aircraft. Numerous other aspects are provided.

According to some embodiments, system and methods are provided, comprising receiving one or more mission objectives for an aircraft mission, and condition data at a mission execution module; generating, via the mission execution module, a mission plan executable to address at least one of the one or more mission objectives via manipulation of a power-thermal management system (PTMS); receiving the generated mission plan at the PTMS directly from the mission execution module; and automatically executing the generated mission plan to operate an aircraft. Numerous other aspects are provided.

Gaskets, including aircraft gaskets, are disclosed, the gaskets having an elastomeric gel body and substantially incompressible skeletons. The bodies may be pliable and deformable and, in one example, may be comprised of a two-part chemically cured polyurethane that sets up as a gel after mixing with the web so that it is fully integral with the web and so that there is substantially no air bubbles or air pockets left in the web. The web may be a regular shaped web and made of nylon.

The present application discloses a method of determining one or more fuel characteristics of an aviation fuel suitable for powering a gas turbine engine of an aircraft, the gas turbine engine having a combustor supplied with fuel from a fuel system, the method comprising: determining a mass of the fuel being supplied to the combustor; determining a corresponding volume of the fuel being supplied to the combustor; and determining one or more fuel characteristics based on the determined mass and volume. Also disclosed is a fuel characteristic determination system, a method of operating an aircraft, and an aircraft.

A dual use UAV or “drone” can include a battery and primary processor located at a fuselage, as well as two separate modular units removably coupled to the fuselage and in communication with the primary processor. The two separate modular units can interact with each other to provide an enhanced operation while the drone is in flight. One modular unit can be an ISR unit having a video camera, and the other modular unit can be a cargo unit. The enhanced operation can involve the ISR unit using its video camera to identify a delivery location for a cargo pod of the cargo unit. Alternative modular units can include a secondary ISR unit, a cargo fuel pod unit, or a robotic arm assembly. Standardized interfaces coupled to the fuselage can enable the ready removal of one modular unit and installation of another one.

The present disclosure is directed to a system for controlling an output of a gas generator via an operator manipulated input device. The system includes one or more sensors measuring one or more environmental conditions, a gas generator shaft speed, and a power turbine torque. The system further includes an operator manipulated input device and one or more controllers including one or more processors and one or more memory devices. The one or more memory devices stores instructions that when executed by the one or more processors cause the one or more processors to perform operations. The operations include receiving, via an operator manipulated input device, a throttle lever position defining at least an idle position, a takeoff position, and one or more intermediate positions therebetween; receiving, via one or more sensors, one or more environmental conditions, wherein the environmental condition includes one or more of an ambient air temperature, an ambient air pressure, and an ambient airflow rate; determining, via the controller, a first commanded fuel flow of the gas generator based on a gas generator speed output curve based at least on the throttle lever position, the one or more environmental conditions, and a coefficient reference table; determining, via the controller, a second commanded fuel flow of the gas generator based on a power turbine torque output curve based at least on the one or more environmental conditions; and generating, via the gas generator, a gas generator output based on the first commanded fuel flow or the second commanded fuel flow.