Aircraft display systems and methods with flight plan deviation symbology

1. An aircraft system comprising:

a deviation module configured to

receive a flight plan with a flight segment to a waypoint, the flight plan including a lateral profile, a vertical profile, and a time profile, the time profile including a predetermined time of arrival associated with the waypoint,

receive a current lateral position and a current altitude,

estimate an estimated time of arrival associated with the waypoint,

compare the current lateral position to the lateral profile to generate lateral deviation,

compare the current altitude to the vertical profile to generate vertical deviation, and

compare the predetermined time of arrival to the estimated time of arrival to generate time deviation; and

a visual display coupled to the deviation module and configured to display deviation symbology representing the lateral deviation, the vertical deviation, and the time deviation,

wherein the deviation symbology includes

a reference circle, and

a first indicator circle that is sized relative to the reference circle to indicate time deviation.

2. The aircraft system of claim 1 , wherein the reference circle and the first indicator circle are coincident when the time deviation is zero.

3. The aircraft system of claim 1 , wherein the deviation symbology includes

a vertical axis,

a horizontal axis that intersects the vertical axis at a reference point,

a second indicator positioned along the horizontal axis to represent lateral deviation based on a first distance from the reference point, and

a third indicator positioned along the vertical axis to represent vertical deviation based on a second distance from the reference point.

4. The aircraft system of claim 1 , wherein the deviation symbology includes

a vertical axis,

a horizontal axis that intersects the vertical axis at a reference point, and

a second indicator positioned relative to the horizontal axis and the vertical axis to indicate lateral and vertical deviation.

5. The aircraft system of claim 4 , wherein the reference circle and the first indicator circle are superimposed on the vertical axis and horizontal axis.

6. The aircraft system of claim 1 , wherein the visual display is a primary flight display and the deviation symbology is stand-alone symbology.

7. The aircraft system of claim 1 , wherein the visual display is a primary flight display configured to display a flight path vector, the deviation symbology being incorporated into the flight path vector.

8. The aircraft system of claim 1 , wherein the visual display is a primary flight display configured to display a flight path director, the fused symbology being incorporated into the flight path director.

9. The aircraft system of claim 1 , wherein the visual display is a primary flight display configured to display an airspeed scale, and wherein the deviation module is configured to generate a speed recommendation displayed at a position on the airspeed scale to arrive at the waypoint at the predetermined time.

10. The aircraft system of claim 1 , wherein the visual display is a navigation display configured to display a lateral map, the deviation symbology being displayed on the lateral map, wherein the visual display is further configured to display a flight plan trajectory based on the flight plan and a time bug positioned on the flight plan trajectory representing the time deviation.

11. The aircraft system of claim 1 , wherein the visual display is an instrumentation display configured to display a current throttle position and a time bug positioned relative to the throttle position to arrive at the waypoint at the predetermined time.

12. The aircraft system of claim 1 , wherein the visual display is a synthetic vision system and the deviation symbology includes a range ring.

13. A method of displaying deviation symbology comprising the steps of:

receiving a flight plan with a flight segment to a waypoint, the flight plan including a lateral profile, a vertical profile, and a time profile, the time profile including a predetermined time of arrival associated with the waypoint;

receiving a current lateral position and a current altitude;

estimating an estimated time of arrival associated with the waypoint,

comparing the current lateral position to the lateral profile to generate lateral deviation;

comparing the current altitude to the vertical profile to generate vertical deviation;

comparing the predetermined time of arrival to the estimated time of arrival to generate time deviation; and

displaying fused deviation symbology representing the lateral deviation, the vertical deviation, and the time deviation,

wherein the displaying step includes displaying a reference circle and a first indicator circle that is sized relative to the reference circle to indicate time deviation.

14. The method of claim 13 , wherein the displaying step includes displaying

a vertical axis,

a horizontal axis that intersects the vertical axis at a reference point,

a second indicator positioned along the horizontal axis to represent lateral deviation based on a first distance from the reference point, and

a third indicator positioned along the vertical axis to represent vertical deviation based on a second distance from the reference point.

15. The method of claim 13 , wherein the displaying step includes displaying

a vertical axis,

a horizontal axis that intersects the vertical axis at a reference point, and

a second indicator positioned relative to the horizontal axis and the vertical axis to indicate lateral and vertical deviation.

16. The method of claim 15 , wherein the displaying step includes displaying the reference circle and the first indicator circle superimposed on the vertical axis and horizontal axis.