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Aviation Sri Lanka 

There have been changes in flight routes to facilitate the aircraft's Area Navigation (RNAV) system in Sri Lankan FIR. These changes in routes would ease the operation of Global Positioning System (GPS) environment and itsí associate components.


The concept of Path Objects 

The concept of Path Objects will make an aircraft's Area Navigation (RNAV) system easier to use in a Global Positioning System (GPS) environment. The idea is to add software to the aircraft's flight path computer systems (usually called the RNAV system) that would allow the aircraft to calculate its flight path based on patterns. For example, rather than representing a circular path as a series of coordinates along the circumference, the path object algorithm in the RNAV computer would calculate the precise path based only on the center and radius. In that way the pilots, controllers, and automation systems can easily exchange information about their intended paths. The primary benefit is to provide the operational capability to implement flexible RNAV routes.

Path Objects (POs) are instructions stored in an RNAV computer for constructing a flight path based on a few inputs in the form of fixes and parameters. With path objects, a few more patterns would be added that would allow unlimited flexibility in aircraft routes. With this new path object language, the controller and pilot can easily modify the intended path by changing just a single parameter in the RNAV computer. This keeps the RNAV system in control of defining the path, which is not possible if the controller is forced to revert to radar vectoring. In a pure data link environment, it reduces the amount of information that must be exchanged to maintain the integrity of intent information and retains situational awareness for the pilot and controller.

There are not that many types of POs that would be required to define all of the maneuvers that are performed by commercial aircraft. Consequently, with just a few shapes it would be possible to define all of the RNAV routes in the world. POs will enable the generation of many specific routes without storing them ahead of time. Consequently, the size of the navigation database can be significantly reduced which, in turn, has the potential to reduce the costs of collecting, processing, transferring, and storing the RNAVs navigation database;

Other benefits, besides the reduction in database size will be derived from implementing the PO concept

bulletIn the future, an automated data link system will increase the ability to take advantage of the airborne capabilities by having very flexible RNAV defined routes;
bulletPilots will gain increased situational awareness by being on RNAV routes while flying familiar patterns expressed as a simple series of POs; and
bulletUsing POs in a free-flight environment, an aircraft can quickly and precisely transmit its intentions to the ground for processing.