Methods, systems, and apparatus, including computer programs encoded on computer storage media, for unmanned aerial vehicle authorization and geofence envelope determination. One of the methods includes determining, by an electronic system in an Unmanned Aerial Vehicle (UAV), an estimated fuel remaining in the UAV. An estimated fuel consumption of the UAV is determined. Estimated information associated with wind affecting the UAV is determined using information obtained from sensors included in the UAV. Estimated flights times remaining for a current path, and one or more alternative flight paths, are determined using the determined estimated fuel remaining, determined estimated fuel consumption, determined information associated wind, and information describing each flight path. In response to the electronic system determining that the estimated fuel remaining, after completion of the current flight path, would be below a first threshold, an alternative flight path is selected.

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for unmanned aerial vehicle authorization and geofence envelope determination. One of the methods includes determining, by an electronic system in an Unmanned Aerial Vehicle (UAV), an estimated fuel remaining in the UAV. An estimated fuel consumption of the UAV is determined. Estimated information associated with wind affecting the UAV is determined using information obtained from sensors included in the UAV. Estimated flights times remaining for a current path, and one or more alternative flight paths, are determined using the determined estimated fuel remaining, determined estimated fuel consumption, determined information associated wind, and information describing each flight path. In response to the electronic system determining that the estimated fuel remaining, after completion of the current flight path, would be below a first threshold, an alternative flight path is selected.

Example implementations relate to systems and techniques for coordinating and assigning aircraft and ground vehicles to runways to prevent wrong surface events and to minimize runway incursions. An aircraft initially receives instructions identifying a runway for use by the aircraft generated by an Air Traffic Control Tower (ATCT) and then subsequently receives a runway identification (ID) code transmitted by a sensor subsystem positioned proximate the runway, which is used by a runway-aircraft pairing management system. An onboard verification system of the aircraft then compares the runway ID code with the runway identified in the ground navigation instruction and uses an onboard transmitter to transmit a confirmation to the sensor subsystem positioned proximate the runway when the code and runway match. The aircraft then displays instructions for the aircraft to proceed with use of the runway.

In at least some implementations, a method of controlling a vehicle-based drone includes determining a need for secondary navigation data within a sensing area of one or more vehicle sensors, commanding the drone to depart from the vehicle, receiving at the vehicle secondary navigation data from the drone, and operating the vehicle at least in part as a function of the secondary navigation data.

A method is disclosed. The method includes receiving an indication of presence of an aircraft in a vicinity of an uncrewed aerial vehicle (UAV) which is flying along a flight path. The method also includes decelerating, based on the received indication, the UAV to reduce a ground speed along the flight path. The method additionally includes descending, after reducing the ground speed, the UAV to a hover position. The method further includes determining, while the UAV is in the hover position, whether to resume the flight path or to land the UAV based on a determination of continued presence of the aircraft in the vicinity of the UAV. The method also includes controlling the UAV based on the determination of whether to resume the flight path or to land the UAV.

A method for a gas turbine engine includes calculating an inlet airflow distortion value at a reference area within an airflow duct and in front of a fan of the gas turbine engine. The inlet airflow distortion value is indicative of an air pressure of an air vortex at the reference area caused by a set of crosswind conditions. The calculating is based on a ratio between an inlet airflow static air pressure in the reference area and a total ambient air pressure. The inlet airflow distortion value is compared to a threshold corresponding to a permissible amount of inlet airflow distortion at the reference area for the set of crosswind conditions, and, based on the comparison indicating that the inlet airflow distortion exceeds the threshold, an inlet airflow distortion notification is provided. A system for a gas turbine engine and a method for a gas turbine engine are also disclosed.

Particular embodiments described herein provide for modular device assemblies and methods for enabling maintenance and servicing, particularly by an unmanned aerial vehicle. A device assembly comprises a plurality of modules, each module having control circuitry, a communications port and contact points to couple the modules. When the modules are coupled, the communications ports are connected to create a bus for communications between the modules. The modular device structure where modules are removable and replaceable allows for an unmanned aerial vehicle to perform maintenance on the device.

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for an unmanned aerial system inspection system. One of the methods is performed by a UAV and includes receiving, by the UAV, flight information describing a job to perform an inspection of a rooftop. A particular altitude is ascended to, and an inspection of the rooftop is performed including obtaining sensor information describing the rooftop. Location information identifying a damaged area of the rooftop is received. The damaged area of the rooftop is traveled to. An inspection of the damaged area of the rooftop is performed including obtaining detailed sensor information describing the damaged area. A safe landing location is traveled to.

An unmanned helicopter platform includes a fuselage, a tail coupled with the fuselage, a payload rail coupled with and extending along the fuselage and a main rotor assembly coupled with the fuselage. The tail includes a tail rotor and a tail rotor motor. The tail is removably coupled to the fuselage. The main rotor assembly includes a main rotor having an axis of rotation and a main rotor motor.

Methods, systems, and apparatus for drone navigation within a property. A method includes detecting an obstacle in a navigation path of a drone, determining a classification of the obstacle, determining whether to temporarily land based on the classification of the obstacle, and temporarily landing the drone until the obstacle clears the navigation path of the drone.