1. Seville, Spain 24-25 June 2008 REACT: The FMS Perspective Keith Wichman – GE Aviation Systems

2. REACT Workshop Seville, Spain 24 th -25 th June 2008 2 Background The Flight Management System computes the full 4D trajectory from runway to runway This trajectory represents the optimal way to fly the entered route while honouring all constraints The FMS then provides closed-loop guidance to this trajectory The trajectory is continuously updated to account for changing conditions or to reflect deviations from the planned route However….

3. REACT Workshop Seville, Spain 24 th -25 th June 2008 3 Background The FMS and Ground-based Trajectory Predictors / DSTs have been developed independently Different inputs, models, and requirements lead to different trajectories for the same aircraft Often leads to non-optimal, tactical commands to ensure separation and safety ≠

4. REACT Workshop Seville, Spain 24 th -25 th June 2008 4 Background Thus, there is an urgent need to synchronize the trajectory as well as how the aircraft intends to fly that trajectory. Using the Reference Business Trajectory as the initial reference, this collaborative trajectory management allows for an “optimization” of the system as a whole while minimizing the deviation from that RBT.

5. REACT Workshop Seville, Spain 24 th -25 th June 2008 5 Previous Experiments Boeing 737 FMS provides ARINC 702A-1 Trajectory-Intent Bus Output via 429 bus and/or ACARS Examined as part of NUP2+ project Dedicated flight trials in 2006 and 2007

6. REACT Workshop Seville, Spain 24 th -25 th June 2008 6 Previous Experiments – ARINC 702A-1 Trajectory Bus – Aircraft current-state information 2Hz – Aircraft 4D trajectory predictions (Intent) –Each minute or when FP changes –Full trajectory to runway –Includes vertical wpts and turns – Dedicated ARINC 429 Bus and/or via ACARS Intent Bus in B737 U10.6 & U10.7 FMS ARINC429 Trajectory Bus AOCATC Current A/C State and Trajectory Predictions ACARS

7. REACT Workshop Seville, Spain 24 th -25 th June 2008 7 Previous Experiments NUP2+ Examined – dynamics and stability of trajectory data – Frequency of downlink – Bandwidth issues Now need to look at content and synchronization issues

8. REACT Workshop Seville, Spain 24 th -25 th June 2008 8 Motivation: The FMS Perspective The flight intent is the only directly controllable input, but it is the aircraft intent that really differentiates the output trajectory Flight Plan - Company Route - SID/STAR - Airways - Crz FL - Waypoints - Constraints AC Modelling - ECON Speeds - Thrust Limits - FPA / Vert Speed - Turn (Dir/Hdg) - Flyover or Flyby “Rules” - Bank Angle - Max Alt - Perf Defaults - Geo vs Idle - Min/Max Vert Spd Path Construction - Lateral Geometry - Equations of Motion - Accuracy - Limiting

9. REACT Workshop Seville, Spain 24 th -25 th June 2008 9 Motivation: The FMS Perspective Problem: – The Aircraft Intent generation process is hidden – Only Flight Intent can be “tweaked” to change the trajectory – The output trajectory is useful for conflict detection, but… – …conflict resolution via a new trajectory is not so simple Possible Solution: – Knowledge of the Aircraft Intent – Use of an “Inverse Trajectory Engine” to translate Aircraft Intent to a new Trajectory – Use of an “Inverse Intent Engine” to translate Aircraft Intent to new Flight Intent for input to the FMS

10. REACT Workshop Seville, Spain 24 th -25 th June 2008 10 Air Ground TE’ Flight Intent Aircraft Trajectory TE Flight Intent Aircraft Intent Aircraft Trajectory FPN, Constraints IE IE’ Motivation: The FMS Perspective

11. REACT Workshop Seville, Spain 24 th -25 th June 2008 11 Summary Need to break down the wall between the air & ground trajectories