Doug Meyerhoff, air traffic management expert and co-founder of Airspace Unlimited presents his assessment of constraints facing Free Route and Fixed Route Airspace and explores ways to mitigate the problems.
For those of us who have contemplated geometry for more than 10 minutes will know that the shortest distance between two points is in fact a straight line.
And for those with more than a passing knowledge of how the global air routes work, the ideal of straight-line routing is slowly becoming a reality.
Being arguably the safest industry in the world comes as both a blessing and a curse to the aviation industry.
While the navigational capabilities of modern aircraft have leapt forward in orders of magnitude, the flexibility of the air route structure has sadly lagged behind.
This gap between aircraft capability and network flexibility is being addressed in a number of ways. In Europe, this gap has been addressed through the introduction of the Functional Airspace Blocks (FABs) and the implementation of Free Route Airspace (FRA).
As these concepts mature, Air Traffic Management data and surveillance systems are being upgraded to cope with the Flight Planning Data requirements associated with these new route possibilities. However, there still remain significant airspace constraints hampering a true Free Route environment.
These constraints come mainly in the form of various airspace reservations.
The most common and easily recognized owner of these airspace reservations is the military. It is acknowledged that military training and operational requirements are of major importance to national strategic policy, and that military budgets and operational resources are continually being stretched.
The enhanced capability of the latest weapons platforms require increased airspace in order to effectively train crews in maximizing the effectiveness of these systems.
For example, the United Kingdom’s Royal Air Force has recently introduced an increase in the size of airspace reservations over the North Sea. This proposal will impact a number of busy routes affecting civil air traffic routing from northern Europe to North America.
The major problem facing Air Navigation Service Provider’s, Military Mission planners, Flight Planning Service Providers, such as Lido, Jeppeson, etc and the airlines is the ability to effectively manage the status of airspace availability.
Predicting Commercial Free Route demand based on historical track data and forecast weather in as close to real time as possible is the gold standard in optimizing airspace reservations.
The desire to merge all of this data into one platform is something that Airspace Unlimited has worked on over the past 3 years, aided with a research grant from the UK Department for Transport (DfT), along with funding from innovation agency, Innovate UK.
The focus of the solution has been to improve access to larger swathes of Restricted Airspace under the FUA concept. This has been accomplished by encouraging flexibility in the time, altitude and location of planned Military training activity. Although the primary focus for the work thus far has been on maximizing FUA principles, other applications for the technology are being explored.
However, in a recent European Regional meeting of the International Federation of Air Traffic Control Associations, a number of areas of concern were discussed. Among the topics raised was the increasingly common practice of airlines to flight plan less fuel efficient routes in order to avoid excessive route charges associated with the more direct routes. Often after filing a less direct route in order to avoid higher charges, the flight crew will request for a more direct route from the sector controller on initial contact.
It is in the nature of most controllers to do their best to accommodate these requests on a tactical basis. The practice of filing one route and then immediately asking for a tactical change distorts sector traffic demand and reduces predictability for the operators and the Air Navigation Service Provider.
Asking for a reroute on frequency also denies the ANSP the appropriate route charges for that particular sector. Rather than being in a sector for 10 minutes this tactic can extend the time on frequency for the initial sector as well as involving coordination with other sectors within the en-route control centre that would not normally be planning to handle that aircraft.
As an example, imagine an aircraft planning to fly from Manchester to the Azores. The flight plan filed routes west out of Manchester toward Dublin prior to turning southbound. The objective of the flight plan is to minimize the time spent in UK airspace where the air navigation charges are more expensive than those in the Irish Republic. In reality the plan is for the pilot to request direct a UK FIR exit point off Lands End as soon as possible after departure in an effort to reduce the track miles. This saves the airline time and fuel. This action results in the UK ANSP losing out on route charges, it also handles increased, unplanned sector loading on an ad hoc basis.
The tool being developed by Airspace Unlimited will also enable ANSPs to provide a traffic management solution to encourage Commercial Traffic to take advantage of variably priced “charging tunnels”. This concept, supported in EU legislation, allows an ANSP to encourage traffic to route via preferred tracks by offering a temporarily reduced or scaled navigation charge along specific tracks or through preferred sectors.
By employing this functionality, an ANSP can manage traffic demand in a manner that best utilizes their sector alignment and capacity. ATM capacity induced delays can therefore be managed more effectively by offering airlines routing options that may involve slightly increased track distance, offsetting that increase distance with specifically targeted reduced route charges. This will also allow ANSPs to provide relief to sectors experiencing excessive demand.
This proposed concept of operations presents all stakeholders with a positive result. Commercial operators will save with reduced navigation charges while the ANSP can generate revenue by encouraging operators to utilize airspace that traffic may otherwise actively avoid.
This model can also be applied in an environment that commercial operators actively avoid, in a desire to sidestep a more expensive, direct route.