A flight director command indicator for a cathode ray tube display has a single cue positioned in roll, pitch and translation by combining roll attitude and pitch attitude command signals. It includes cooperating indicia for providing visual commands to bring the aircraft to a predetermined flight path of attitude to satisfy the flight director command.

A transponder having a subsystem for providing an altitude alert function signifying a deviation from a set altitude is described. The subsystem includes an input for receiving an altitude deviation limit associated with the set altitude, a CPU receiving updated altitude and determining a difference between the updated altitude and the set altitude associated with the altitude deviation limit, and a transponder subsystem output device for providing the difference between the updated altitude and the set altitude to a user.

Apparatus for visually displaying simultaneously on one screen two variables that characterize the path followed by a land, marine or airborne vessel with reference to a preselected or ideal path that extends from a beginning point to an ending point. Using two distinguishable icons or other indicia for the two variables, the screen displays a single one-dimensional scale and displays the two indicia, each of which represents one of the following differences: (1) the difference between at least one of the two horizontal location coordinates for the present vessel location and for a nearest point on the preselected path; (2) the difference between the elevation coordinates for the present vessel location and for a nearest point on the preselected path; (3) the difference between the present horizontal bearing angle of the vessel path and the horizontal bearing angle along the preselected path at a nearest point on the preselected path; and (4) the difference between the present vertical bearing angle of the vessel path and the vertical bearing angle along the preselected path at a nearest point on the preselected path. Alternatively, the screen may display two one-dimensional scales with either two indicia, three indicia or two mutually exclusive sets of two indicia. Alternatively, two indicia may be used to define the size of a rectangle and the quadrant it appears in, for representation of the two indicia.

A primary flight display with three-dimensional capability provides information in an intuitive format for enhanced situational awareness. The display also includes other navigational data such as airspeed, attitude, altitude, and heading. The display may also include three view slices, a pictorial autopilot status indicator, vertical and lateral deviation and deviation history, glide slope and localizer information, airport and runway information, past position history of the aircraft and other nearby aircraft. The display may depict potential threats to the aircraft such as terrain or other manmade obstacles, nearby aircraft, severe weather thus increasing situational awareness with respect thereto. In a preferred embodiment, the three dimensional tactical map is implemented as a frequency separated display.

A system and method for intervention control of an aircraft in the event of pilot command error whether voluntary or involuntary. Impending detection of a chaotic condition associated with a maneuvering aircraft enable early prediction and control of the aircraft where solutions based upon performance prediction are available. A further feature of the present intervention control of the aircraft enables an equipment malfunction detection signal substitution of a satisfactory equipment signal.