Methods and apparatus for observer-based landing control of a vehicle

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.