Abstract: A gearbox assembly includes a plurality of planet gears. At least one planet gear of the plurality of planet gears includes a layshaft that supports a first stage planet gear and a second stage planet gear. The at least one planet gear is characterized by a Radial Stage Distance greater than or equal to 30 millimeters and less than or equal to 100 millimeters. The Radial Stage Distance is Rrm1?Rrt2. Rrm1 is a first stage rim inner radius of the first stage planet gear and Rrt2 is a second stage root radius of the second stage planet gear.

Abstract: A variable pitch propeller assembly operatively coupled with an engine and methods for controlling the pitch of a plurality of propeller blades thereof is provided. In one example aspect, the variable pitch propeller assembly includes features for combining overspeed, feathering, and reverse functionality in a single secondary control valve. The secondary control valve is operable to selectively allow a controlled amount of hydraulic fluid to flow to or from a pitch actuation assembly such that the pitch of the propeller blades can be adjusted to operate the variable pitch propeller assembly in one of a constant speed mode, a feather mode, and a reverse mode.

Abstract: A gearbox assembly includes a gear assembly that includes a planet gear, a pin disposed within the planet gear, a first sensor, and a second sensor. The first sensor is disposed within the pin and is configured to produce a signal indicative of a strain of the pin. The second sensor is disposed within the pin and is configured to produce a signal indicative of a vibration of the pin. Another gearbox assembly includes a gear assembly including a planet gear, a pin disposed within the planet gear, and a strain sensor. The strain sensor is disposed within the pin and is configured to produce a signal indicative of a strain of the pin. The strain sensor is located within the pin at a circumferential location of the pin that is opposite to a location of a force acting on the pin when the planet gear rotates about the pin.

Abstract: A lubrication system for an aerial vehicle, the lubrication system including: a lubrication oil (LO) tank configured to operate at a first internal pressure; and an intake chamber (IC) configured to operate at a second internal pressure greater than the first internal pressure, the IC including an ingress port configured to receive LO from a sump of an equipment of the aerial vehicle; an overflow port in fluid communication with the LO tank; and a supply port in fluid communication with the sump and configured to supply LO to the sump.

Abstract: A variable pitch propeller assembly operatively coupled with an engine and methods for controlling the pitch of a plurality of propeller blades thereof is provided. In one example aspect, the variable pitch propeller assembly includes features for combining overspeed, feathering, and reverse functionality in a single secondary control valve. The secondary control valve is operable to selectively allow a controlled amount of hydraulic fluid to flow to or from a pitch actuation assembly such that the pitch of the propeller blades can be adjusted to operate the variable pitch propeller assembly in one of a constant speed mode, a feather mode, and a reverse mode.