Wake
Vortex Separation
UnderIn Iinstrument Flight Rulesmeteorological conditions
(IFRMC),
thecurrently
applied Wake Vortex (WV) constraints are not weather dependent and the separation
standards between aircraft areistherefore
based on a a
worst-case scenario. The spacing is determined by considering the
leader/follower aircraft weight categories and wake persistence observed during
atmospheric conditions favourable to long vortex life. These separation minima
are often very conservative; although they do not
completely avoid the effect of WV, but long experience in applying the separation minima demonstrates that they are
sufficient to be safe in most meteorological conditions.
Several
technologies to detect and predict WV, such as LIDAR (Light Detection and
Ranging), have been developed during the last years. These technologies are now
quite mature. Weather conditions in which
WV decay quickly can be identified, and this information can be used to predict
the severity of WVas.; tThere is potential for
making the separation distances dependent on these predictions as well as
actual aircraft weight. This could increase runway capacity in certain weather
conditions.
The strategy is firstly to use the detection means to develop better Wake
Vortex models allowing a prediction of propagation and severity, secondly to
use the technical means to monitor the actual situation in order to serve as a
safety net.
None of these new systems and technologies are today connected to today, there is
no link toATC and subsequently no system integrating all the
sources of information together at a single source, accessible by all ATC systems
(en-route, approach, tower and arrival/departure managers)). and remain for the time
being at the R&D stage
The ATC-WAKE project intended to develop and build an
operational platform. The following tasks have until now been undertaken and
published by the ATC-WAKE project :
·
Operational requirements
·
Operational concepts and procedures
·
Users requirements
·
System
requirements
based on operational concepts and users requirements
The following
work is ongoing:
·
Operational: WV information and HMI for ATC operations,
·
Technical: platform to interface WV detecting and
forecasting systems to current ATC systems.
This work will
be published in 2004.
Steps towards Implementation
As a first
step towards implementation
of an ATC-WAKE platformSystem, a preliminary operational
concept together with requirements
for the
application of aircraft using separation minima based on WV detection
and prediction information have been defined.
Next steps in the project are aimed
to at further validating e such requirements
through system design and safety assessment and then operational feasibility
evaluation.
During the
development of ATC-WAKE requirements, a number of key issues have been
identified and still need
to be carefully assessed:
·
Transitions between ATC-WAKE and ICAO separation modes
·
Aircraft separation and sector loading
·
Evaluation of safety requirements
·
Evaluation of capacity benefits
During the next phase, the operational feasibility of
the new integrated ATC system will be evaluated. It will include an analysis of
interoperability with existing ATC systems as well as usability and
acceptability by its foreseen end-users (air traffic controllers). After
definition of operational concepts and procedures, this will be realised
through fast-time simulations with a total airspace and airport modelling tool.
For further information, please contact Antoine Vidal.