This paper describes a methodology for the integration and evaluation of fast-time wake models with flight data. The National Aeronautics and Space Administration conducted detailed flight tests in 1995 and 1997 under the Aircraft Vortex Spacing System Program to characterize wake vortex decay and wake encounter dynamics. In this study, data collected during Flight 705 were used to evaluate NASA's fast-time wake transport and decay models. Deterministic and Monte-Carlo simulations were conducted to define wake hazard bounds behind the wake generator. The methodology described in this paper can be used for further validation of fast-time wake models using en-route flight data, and for determining wake turbulence constraints in the design of air traffic management concepts. Γ = vortex circulation (ft 2 /s) 0 Γ = initial vortex circulation (ft 2 /s) V 0 = initial vortex descent velocity (ft/s) b 0 = initial vortex pair separation (ft) y 0 = initial vortex pair lateral offset from a reference point (ft) z 0 = initial vortex pair vertical offset from a reference point (ft) N = dimensional Brunt-Väisälä frequency (s -1 ) N* = non-dimensional Brunt-Väisälä frequency = 1 0 0 − V Nb ε = dimensional eddy dissipation rate (ft 2 /s 3 ) ε * = non-dimensional eddy dissipation rate = ( ) 1 0 3 / 1 0 − V b ε θ = potential temperature/theta (K) 2 T = temperature (°F) T L = Sarpkaya time-to-link u = east-west velocity component (ft/s) v = north-south velocity component (ft/s) ρ = air density (sl/ft 3 ) ∆t e = vortex encounter time (s) ∆x = distance between generator and follower at time of encounter (nmi) g = acceleration due to gravity (ft/s 2 ) W G = weight of the generator (lb) b F = follower wing span (ft) b G = generator wing span (ft) F Y = y-coordinate of follower's center of gravity normalized by b G F Z = z-coordinate of follower's center of gravity normalized by b G s = half of vortex pair separation (b 0 ) normalized by b G c r = vortex core radius size normalized by b G I xx = roll moment of inertia (sl·ft 2 ) F λ = wing taper ratio of the follower V F = follower airspeed (ft/s) V G = generator airspeed (ft/s) q = free-stream dynamic pressure (lb/ft 2 ) v l C = vortex-induced rolling moment coefficient F L C α = three-dimensional lift curve slope of the follower c l C = pilot input roll control corresponding to maximum aileron deflection p l C = roll damping coefficient φ = bank angle (deg) ∞ φ = maximum bank angle of the aircraft without control input (deg) max φ = maximum vortex-induced bank angle (deg)

Unmanned Aerial Vehicles (UAVs) can be used to access remote areas, e.g., for surveillance missions. Collaboration between them can help overcome communication constraints by building airborne relay networks that allow beyond line of sight communication. This research investigates whether a single human operator can supervise multiple UAVs in a collaborative surveillance task under communication constraints. We designed an ecological interface to support operators in their task and increase system flexibility. A preliminary humanin-the-loop study was done to investigate operator task performance and evaluate interface components. It was shown that operators are able to successfully operate surveillance missions under communication-and battery constraints. Participants did, however, not succeed to do this without separation conflicts and communication losses, which indicates that the interface lacks elements representing endurance and separation assurance. To an extent, the interface design turned out to be scalable, with a few remaining visualizations that cause clutter for large numbers of UAVs. More advanced ways of displaying information on request and grouping of select information is warranted to further improve the interface.