Abstract: A fixed-pitch bolted propeller includes: a hollow hub body configured for attachment to a rotatable shaft, where the hollow hub body includes connection ports circumferentially distributed on an outer surface thereof; propeller blades, where each of the propeller blades terminates in a blade flange attached to the outer surface of the hollow hub body at one of the connection ports; retention plates positioned on an inner surface of the hollow hub body adjacent to the connection ports, where the retention plates include threaded recesses; and bolts extending through bolt holes in the blade flanges and the connection ports and into the threaded recesses of the retention plates to secure the propeller blades to the hollow hub body. The retention plates and the bolts each comprise a material having a tensile strength of at least about 125 ksi and/or a fatigue endurance limit of at least about 50 ksi.

Abstract: A system includes a gas turbine engine, a generator coupled with the gas turbine engine, and controller circuitry. The generator may be rotatable by the gas turbine engine to generate electric power on a load bus. The controller circuitry may control the load bus to manage an output torque of the gas turbine engine in accordance with a load demand present on the generator. The controller circuitry may dynamically alternate supply of electric power from the load bus to a first load and a second load to maintain operational transient parameters of the gas turbine engine within a predetermined range.

Abstract: A system includes a gas turbine engine, a generator coupled with the gas turbine engine, and controller circuitry. The generator may be rotatable by the gas turbine engine to generate electric power on a load bus. The controller circuitry may control the load bus to manage an output torque of the gas turbine engine in accordance with a load demand present on the generator. The controller circuitry may dynamically alternate supply of electric power from the load bus to a first load and a second load to maintain operational transient parameters of the gas turbine engine within a predetermined range.

Abstract: A power management system may include an energy source and a generator driven by a gas turbine engine to output generator power to a common bus. A source power converter is electrically coupled between the energy source and the common bus. A controller circuitry includes an adaptive filter to filter a power signal indicative of power consumption of a variable load on the common bus, and outputs a filtered signal as a load demand signal to the generator. A source demand error signal is also output to control the source power converter to supply power from the energy source to the common bus. The controller circuitry is further configured to automatically adjust the adaptive low pass filter in accordance with the power consumption of the dynamic load and the load demand signal of the generator.

Abstract: A towable antenna system is deployable and retrievable from and tetherable to an underwater vehicle while the underwater vehicle is submerged under water. An underwater vehicle having a towable antenna system is capable of communicating with one or more remote communication systems, the towable antenna system acting as an intermediary for communications between a submerged underwater vehicle and the one or more remote communication systems.