Flight Mechanics, Flight Control and Aeroelasticity

CREDOS - Cross Wind Reduced Separation for Departure Operations

CREDOS is a 3-year project funded by the European Commission (EC) and co-ordinated by EUROCONTROL. The project is being performed by 11 partners with additional support from the FAA and NASA. CREDOS aims to demonstrate the validity of reducing departure separations under conditions of sufficient crosswind.


The need to increase airport capacity is one of the major challenges facing Air Traffic Management (ATM) research today. Major European airports are operating close to their maximum capacity, and often face large delays.
Recent research suggests that such an increase could be achieved by reducing the current wake vortex separation minima while maintaining levels of safety:
For single-runway operations above a certain cross wind threshold, vortices are blown out of the flight corridor and pose no further threats to following aircraft. Therefore, such crosswind conditions, offer a large potential for the tactical use of reduced aircraft separations, leading to increase airport capacity and reductions in mean airport delays.


The aim of this project is to research the feasibility to reduce separations for departures under precise meteorological conditions. Therefore, CREDOS focused on situations for take-off under crosswind conditions. The project will pay particular attention to ensure that all factors that influence the real level of benefit are taken into account.

The main outcome of this project is to deliver a validated operational concept for reduced separations for crosswind departures.


WP1Data CollectionDeparture wake vortex and meteorological data from St. Louis (KSTL) and Frankfurt (EDDF) are collected covering the full range of seasonal operating conditions.
WP2Data Analysis and Wake Vortex Behaviour ModellingAnalysis of the evolution of wake vortices shed by departing aircraft under various atmospheric conditions are undertaken and existing models of WV behaviour are updated to include the departure operation.
WP3Risk Modelling and Risk AssessmentWake Vortex Encounter Probability and Encounter Severity are assessed through risk analysis taking into account a broad range of variables through Monte Carlo simulation and aerodynamic models.
WP4Operational Concept and ValidationA new concept of operations for crosswind departures based on the work of the USA ConOpsEvaluation Team and the European Wake Vortex Concepts Team is defined and validated.
WP5Stakeholders Communication and MarketingA comprehensive communication package for Airports and Airline Operators is developed. There will also be a case study of the implementation of CREDOS at Madrid airport.

Research Scope of the TU Berlin

TU Berlin contributes to Work Package 3 and specifically deals with the development of trajectory models for different kind of aircraft for take-off and departure. The trajectory modelling will take into account the actual wind conditions, different standard instrumental departures and aircraft data like the weight of generator and follower aircraft. Further, TU Berlin will perform piloted wake vortex encounters during take- off and departure using the A330/340 Full-Flight Simulator (Level D) attended by the ZFB (Zentrum für Flugsimulation Berlin). Wake vortex severity criteria will be developed as well as a pilot model for take-off and departure.


  • Deutsches Zentrum für Luft- und Raumfahrt (DLR)
  • Airbus Deutschland GmbH (AD)
  • National Lucht- en Ruimtevaartlaboratorium (NLR)
  • M3 Systems (M3S)
  • Office National d'Etudes et de Recherches Aérospatiales (ONERA)
  • Université Catholique de Louvain (UCL)
  • National Air Traffic Services (NATS)
  • Deutsche Flugsicherung GmbH (DFS)
  • Ingeniería y Economica del Transporte S.A. (INECO)
  • TU Berlin

Previous Projects

  • Assessment of Wake Vortex Safety (S-Wake) with participation of TU Berlin
  • Wake Vortex Encounter (WVE), DFG research project