Overview
Major European airports are operating close to their maximum capacity, and often face large delays. Consequently, the need to increase airport capacity is one of the major challenges facing Air Traffic Management research today.
Recent research suggests that the current wake turbulence separation minima can be reduced under specific conditions while maintaining current levels of safety. In particular, for single runway operations, initial work from the S-WAKE project suggested that, above a certain crosswind threshold, vortices are blown out of the flight corridor and pose no further threat to following aircraft.
As many European airports operate in crosswind conditions for a significant portion of time a large potential for the tactical use of reduced aircraft separations exists, leading to increased airport capacity and reductions in average airport delays.
The aim of the CREDOS project evaluated the feasibility of the use of conditional reduced separations for departures under precise meteorological conditions.
Specifically the CREDOS project objectives are to:
- increase the body of knowledge relating to wake turbulence behaviour during the initial climb phase of flight, and in particular concerning the precise crosswind conditions when the wake turbulence is blown laterally away from the runway, thus allowing a follower aircraft to take-off sooner than is currently permitted by the ICAO standards;
- develop, and then demonstrate the feasibility of, a concept of operation allowing reduced separations for single runway departures under certain crosswind conditions;
- provide all stakeholders with the required information to facilitate the implementation of the CREDOS concept in the near-term (pre-2012).
The project is structured into five Work Packages (WP).
- Departure wake vortex and meteorological data (WP1) covering the full range of seasonal operating conditions will be collected at St. Louis (KSTL) and Frankfurt (EDDF).
- Airports and analysed to update existing models of wake vortex behaviour for departure situation (WP2).
- Then, wake vortex encounter probability and encounter severity will be assessed through risk analysis taking into account a broad range of variables through Monte Carlo simulations and aerodynamic models (WP3).
- WP4 will define a new concept of operations for crosswind departures that will be validated in accordance with the European Operational Concept Validation Methodology (E-OCVM).
- Finally, a comprehensive communication package for ANSPs, Airports and Airline Operators will be developed by WP5 based on a case study of a virtual implementation of CREDOS at Madrid Barajas (LEMD) airport.
Funding
Results
Expected Project Results were:
- A validated concept of operations for reduced separations for crosswind departures.
- End-users Support Packages & Guidance.
- Enhanced wake vortex behaviour models and encounter risk models capable of use for departure situations.
- Proven wake vortex detection configuration for departures.
- Database of wake vortex recordings for departures including meteorological conditions from 2 sites, and
- Documented application of validation method for reduced separations concept.
Meeting the SESAR objectives
The CREDOS concept of operations were identified during the SESAR definition phase as one of the possibilities to improve airport capacity and reduce delays at airport. Specifically, the document "WP3.2.2 - Identification of limits-blocking points for Airport - SESAR definition phase - DLT-0607-322-00-07" identified two airport limits-blocking points that the CREDOS concept of operations may contribute to blow up.
The CREDOS project is in line with the objectives of SESAR. Follow-up actions from CREDOS were also included in the WakeNet-III Community.