# Innovative Integration of Severe Weather Forecasts into an Extended Arrival Manager
## 6 Discussion of Approach Planning Results under Severe Weather Conditions
### Results of Diversion Calculations and Sequence Planning  
For validation of the new support functions implemented in DLR's AMAN, an evaluation was conducted with the AMAN that was linked to a traffic simulation and a questionnaire. The extended AMAN runs in 15 separate modules that communicate with each other via a Maria database. In addition, the DLR's radar display RadarVision is used, which can display aircraft movements as well as additional information on flight plans and the generated trajectories. In addition to the 2D route, this includes the planned altitudes and speed profiles and, during a simulation, the current air situation in relation to the planned 4D trajectory. For traffic simulation, the AMAN was coupled with DLR's ArrOS system. ArrOS enables precise movements along a trajectory and simulates cooperative controllers and pilots. A selection of screenshots from the simulation runs are used to illustrate the possibilities and results of the validation trials with 4D-CARMA. The following pictures are screenshots showing selected traffic and weather situations with different weather nowcast models. Diversion route calculation has to consider different constraints in the TMA and the surrounding sectors. In the TMA, the routes are much more convergent, and the aircraft have to overfly more significant waypoints with specific constraints than in the adjacent sectors. As a result, the AMAN can plan larger-scale diversions in the sectors. In Figure 17, the AMAN plans an early diversion and guides the aircraft EJU34 CD on a more southern route than the STAR intends. For traffic visualization on radar screens, a dark image is preferred by some air traffic controllers. In Figure 18, a dark color scheme was selected with trajectories and a thunderstorm cell. In order to reduce the visual presence of the weather information, some controllers had suggested in the run-up to the SINOPTICA concept's development that convective zones should only be displayed as bordered areas [27]. RadarVision now allows controllers to choose between the two weather presentations of filled and bordered areas and also allows for switching between dark and light-colored traffic visualizations through keyboard input. Figure 17: A large-scale diversion route plan for aircraft EJU34 CD, currently No. 1 in the arrival sequence and approaching MXP from the west. The white arrows indicate the original STAR and the yellow–red dotted line represents the AMAN 4D trajectory. MXP traffic mix from 11 May 2019 with weather from 11 May 2019 and the WRF-RUC nowcast model. A particular challenge was route planning that required diversions around several convective zones moving at different speeds in different directions. In Figure 19, an example of a diversion around four smaller convective areas is plotted for aircraft BEE156H arriving at Malpensa from the northwest. In weather situations of this type, the AMAN must decide independently whether it is more appropriate to fly through the loosely distributed convective zones or to fly completely around the entire affected area. Figure 19: Route calculation for aircraft BEE156H approaching MXP from the northwest through a loose group of convective areas. If several convective cells occur as a group, the AMAN tries to guide aircraft around them as a whole. MXP traffic mix from 11 May 2019 with weather from 6 August 2019 and the RaNDeVIL nowcast model. Figure 18: The dark color scheme with convective zones displayed as bordered areas. Malpensa traffic mix from 11 May 2019 with weather from 11 May 2019 and the WRF-RUC nowcast model. In Figure 20, a 4D trajectory was planned with a diversion right through a convective area. However, following the weather forecast, this cell shifted to the southeast in the course of the following minutes so that, when the aircraft arrived, the route precisely avoided this area. If convective cells appear as a loose group, the AMAN tries to find a straight-line route through them.