Abstract: An hybrid unmanned underwater vehicle comprises a body housing a controller; a vector thruster for propelling the body; deployable wings allowing the unmanned underwater vehicle to traverse by gliding as the unmanned underwater vehicle ascends and descends; a center-of-mass shifter for shifting a center-of-mass of the vehicle to allow the unmanned underwater vehicle to pitch up and pitch down; and one of a multi-stage buoyancy control system within the body and configured to adjust an apparent displacement of the unmanned underwater vehicle and an expandable outer shell configured to adjust an apparent displacement and therefore a buoyancy of the unmanned underwater vehicle.

Abstract: A dual mode pilot burner having a control flame mode of operation and a pilot flame mode of operation, which dual mode pilot burner is suitable for controlling the fuel/air ratio of a main burner when operating in the control flame mode of operation. The dual mode pilot burner includes a burner body having a control flame holder and a pilot flame holder disposed downstream of the control flame holder, a mixing chamber having a fuel gas inlet, an oxidant inlet, and a mixed gas outlet, which mixed gas outlet is in fluid communication with the control flame holder and a fuel gas control valve for controlling a fuel gas flow rate through the fuel gas inlet into the mixing chamber.