Abstract: Methods, apparatus, and articles of manufacture for observer-based landing control of a vehicle are disclosed. An example apparatus includes at least one memory, and at least one processor to execute instructions to at least in response to determining an aircraft is in a flight plan flare regime, determine an estimate state of an aircraft parameter based on an execution of a transfer function of an observer model, the execution of the transfer function based on an altitude command corresponding to the flare regime, determine a gain value based on the aircraft parameter, determine an altitude control input based on the estimate state and the gain value, determine an altitude command output based on the altitude control input and longitudinal dynamics of the aircraft, the longitudinal dynamics generated in response to the aircraft executing the altitude command output, and control an elevator of the aircraft based on the altitude command output.

Abstract: A system for use in generating a command trajectory for an aircraft is provided. The system includes a natural frequency determining module configured to determine a closure rate of the aircraft to a selected flight path, compare the closure rate of the aircraft to a threshold closure rate, and calculate a natural frequency based on whether the closure rate is below the threshold closure rate. The system further includes a command processor coupled to the natural frequency determining module and configured to receive the calculated natural frequency from the natural frequency determining module, and generate a command trajectory using the calculated natural frequency.

Abstract: A method and apparatus for a monitoring module. The monitoring module is configured to identify a difference between measured position information for a controller and expected position information for the controller. The monitoring module is configured to compare the difference with thresholds for managing an autopilot in a control system of a vehicle to form a comparison. The monitoring module is configured to manage an operation of the autopilot based on the comparison such that the autopilot remains operating when a backdrive system is inoperative and an intentional override of the autopilot is absent.

Abstract: A system for use in generating a command trajectory for an aircraft is provided. The system includes a natural frequency determining module configured to determine a closure rate of the aircraft to a selected flight path, compare the closure rate of the aircraft to a threshold closure rate, and calculate a natural frequency based on whether the closure rate is below the threshold closure rate. The system further includes a command processor coupled to the natural frequency determining module and configured to receive the calculated natural frequency from the natural frequency determining module, and generate a command trajectory using the calculated natural frequency.

Abstract: A method and apparatus for a monitoring module. The monitoring module is configured to identify a difference between measured position information for a controller and expected position information for the controller. The monitoring module is configured to compare the difference with thresholds for managing an autopilot in a control system of a vehicle to form a comparison. The monitoring module is configured to manage an operation of the autopilot based on the comparison such that the autopilot remains operating when a backdrive system is inoperative and an intentional override of the autopilot is absent.