1. The Role of Workload for Work Organisation in a Remote Tower Control Center Institute for Flight Guidance, German Aerospace Center (DLR) C. Möhlenbrink, A. Papenfuss, J. Jakobi

2. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 2 The Role of Workload for Work Organisation in a Remote Tower Control Center Overview Background Introduction Hypotheses Method Results Discussion Conclusion

3. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 3 Background Concept Study Vito (Virtual tower) What`s the potential of automation for tower control? Technologies for „Virtuel Reality“ Novel Videotechnologies Immersive Visualisation Head-mounted displays Telepresence „Wearable computing“

4. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 4 Background RApTOr (2005-2007) RTO-Experimental System Installed at Braunschweig airport Prove of technical feasibility Experimental system running since 2005 4 Camera / Zoomcamera Resolution requirement: 30cm/500 m Panoramacamera System (4 cameras + PTZ) Gbit/s – fiber optics LAN RTO-Console “Augmented Vision” Videopanorama

5. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 5 Background RAiCe: Remote Tower Operation Center (start 2008) Research question of interest: How can air traffic control be organized in a control center What is the role of workload for the evaluation of new ATC-concepts Is it possible, one controller operating two small-sized airports? Approach: High fidelity simulations as work probe for a remote tower center Braunschweig Erfurt

6. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 6 Introduction Workload Concept Def. Workload: [Goper & Donchin 86] Limitation on the capacity of an information processing system. taskload versus workload timeline models strategy shifs Influencing factors in aerodrome control: [Vogt et al. 2006] Aerodrome complexity VFR traffic Calculated take-off times Staffing Technological support

7. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 7 (1) Working condition:Single Operator Introduction Designing a Remote Tower Center Far-view Braunschweig Far-view Erfurt BWE ERF BWE ERF weather data integrated (far-view) RADAR BWE RADAR ERF flight strips: black: Depart. EDDE yellow: Arrival EDDE black: Depart. EDVE yellow: Arrival BWE Zoomcamera EDVE Zoomcamera EDDE

8. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 8 Introduction Designing a Remote Tower Center (2) Working Condition:Controller (PL) operating BWE Controller (PL) operating ERF Far-view Erfurt ERF BWE ERF BWE Weather data integrated (far- view) RADAR ERF RADAR BWE Flight stirps ERF: black: Departure ERF yellow: Arrival EDDV + Zoomcamera BWE + Zoomcamera ERF Flight strips BWE: black: Departure BWE yellow: Arrival BWE Far-view Braunschweig

9. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 9 Introduction Designing a Remote Tower Center (3) Working Condition:Team Variant PL (ERF + BWE) and CO (ERF + BWE) Far-view Erfurt ERF BWE ERF BWE Weather data integrated (far- view) RADAR ERF RADAR BWE Flight stirps ERF: black: Departure ERF yellow: Arrival EDDV + Zoomcamera BWE + Zoomcamera ERF Flight strips BWE: black: Departure BWE yellow: Arrival BWE Far-view Braunschweig

10. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 10 Introduction Designing a Remote Tower Center

11. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 11 Augmented Vision Aspects Control and surveillance! Aim: Reducing Head-down times Callsign: - Integration into the far-view - based on transponder data Alternative: - Movement detection - based on a Live-video: Introduction Technological Support VP-CGD D-EAF

12. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 12 Identification of safety-critical situations Modified Cooper-Harper Scale Expert rater: Hierachical structure of questions: – No major influence – Capacity – „workload“ – impossible

13. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 13 Hypotheses traffic hypotheses H1a: For ISA workload ratings (2 min interval) it is expected that the workload ratings are higher for the heavy traffic than for low traffic. H1b: Under low traffic, the single operator has significantly higher workload ratings compared to all other working conditions. The same assumption is made for heavy traffic. H1c: From a theoretical point of view it is predicted that the workload of the single controller operating two airports under low traffic load is not significantly higher, than the workload of controllers operating one airport with low traffic.

14. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 14 Hypotheses augmented vision hypotheses and expert ratings H2 Augmented vision hypotheses For the between-subject-factor it is predicted that working with the callsign displayed on the video, workload is significantly lower compared to working without the callsign in the video. It is assumed that this effect is independent of the working positions or traffic load. Expert Ratings Identifying crucial constraints for the Remote Tower Center Concepts safety critical situation, when one controller is operating two airports

15. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 15 Method High-fidelity simulation: Remote Tower Center Data recording: process data: * throughput Subjective data: * ISA workload ratings * Shape questionnaires * post-run interviews * final questionnaire Objective data: * eye-data recordings * radio com Heatmap Interact

16. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 16 Method Sample Sample: 12 controllers Deutsche Flugsicherung (DFS) Age: mean=34.6 [25,60] years valide controller license Movementsn < 15.000 IFR movements2 < 35.000 IFR movements6 > 100.000 IFR movements4

17. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 17 Method Traffic Scenarios Mixed traffic IFR & VFR total 16 aircraft raising traffic load over time: - 1 st half, low traffic load - 2 nd half, heavy traffic load Events: Two parallel landings Two paralle starts

18. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 18 Method Identification of critical situations Modified Cooper-Harper Scale S1: Landing on airport A + taxing traffic on airport B S2: Similar call signs for aircraft of airport A and B S3: Simultaneous pilot requests at airport A and B S4: Simultaneous starts at airport A and B S5: Simultaneous landing at airport A and B S6: Conflict on airport A, start/landing on airport B

19. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 19 Method Instantaneous Self-Assessment Scale „Online“ 12345 Workload 5

20. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 20 Method Experimental Design Exp. Conditions Between subject factor (1): Augmentation (1) no augmentation(2) callsign within subject factor (2): working design variants C1-C3 * working positions (SO, TC/CO, BC/ EC) within-factor (3) C1C2C3C1C2C3 (3) Traffic (1) low SOTC/COBC/ECSOTC/COBC/EC (2) high SOTC/COBC/ECSOTC/COBC/EC

21. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 21 Results Traffic (low, high) ISA-Workload-Ratings Main effect traffic load: heavy traffic  higher workload low traffic:  lower workload Main effect position: TL, CO, SC  higher workload BC, EC  lower workload Interaction effect traffic*position BC, EC  WL: low ~ heavy traffic TL, CO, SC  low traffic  low WL  heave traffic  high WL

22. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 22 Results Augmented Vision (yes, no) ISA-Workload-Ratings Main effect augmentation: callsign  lower workload no callsign  higher workload Main effect augmentation*position: TL, CO, SC  callsign effect BC, EC  no callsign effect Additional analysis: Augmentation (between-subject factor ) Correlation (team variable, augm.) r=.87 *

23. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 23 Results Ratings for critical situations Situations of interest (N=216) No major influence Influence on Efficiency Influence on Safety Impossible to handle ! (S1) land / taxi 21655 (S2) callsign 8110 (S3) requests 7800 (S4) start / start 14766 (S5) land / land 4677 (S6) conflict /land 3431 (R1) rest category 2442119 TOTAL81743328

24. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 24 Discussion Role of Workload for Work Organisation One controller operating two airports * workload raises * task prioritization * two mental traffic pictures? Each controller operating one airport * workload low * task prioritization * mental traffic pictures? * social aspects? Low traffic periods Each controller operating one airport * workload raises * timing conflicts * two mental traffic pictures? * redundancy Single operator One operator for each airport Team (PL,CO)

25. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 25 Discussion Role of Augmented Vision Effect Previous studies for remote tower  no callsign effect (within-subject design) Operating two airports  callsign effect (training + between subject design) more demanding  callsign effect? problem: high correlation with team variable head-down time issue Seperation of information VP-CGD D-EAF

26. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 26 Discussion Identification of Critical Situations for the RTC Expert judgment (here: online monitoring of one controller operating two airports) Smooth operations: parallel starts (ok) parallel landings (ok) …but 33 situations influencing safety, due to…? 28 situations safety critical, due to…? Shortcomings: No comparable data for other working conditions Role of redundancy in ATC today

27. The Role of Workload for Work Organisation in a Remote Tower Control CenterC. Moehlenrbink June 2011 Folie 27 Conclusion Workload concept insufficient for the evaluation of work design variants Workload as an independent variable influencing controller strategies Work methods offered by different staffing concepts Role of safety critical situations Future work Deeper analysis of expert judgements robust traffic concepts for RTC?