by Philip Clinch, VP Aircraft Solutions, SITA

Better use what’s there

Aviation industry task forces launched by ICAO and IATA are looking into better and proactive aircraft tracking. SITA is playing its part, including provision of a solution using technology already in the aircraft.

The task force investigations are on two levels: one developing governments regulations and one airline community recommendations.

ICAO’s task force may lead to governments requiring airlines to track their aircraft, as aircraft tracking isn’t currently required by any governments outside of the US. IATA is looking at solutions for quicker adoption by its members.

Airlines have not tracked their aircraft for two main reasons. First, because they rely on the Air Navigation Service providers whose airspace they cross to have radar surveillance systems to maintain safe separation. And second, because in most of the world they have not had access to the surveillance data held by ANSPs.

Missing piece

Airline dispatch center systems are generally passive. They depend on reports requested by ATC. The missing piece of the puzzle is how to make these systems proactive.

These reports do not look for expected aircraft communications and provide alerts in the event they stop. That’s one of the things SITA is going to change.

A timely answer

Pending development, trials and testing, as part of its community remit SITA is introducing an advanced end-to-end aircraft tracking solution to meet the industry’s pressing need.

Called AIRCOM Server Flight Tracker, the strong upside of the innovative solution is that it can be developed quickly. It will add only minimal cost to airlines thanks to utilizing existing systems on the aircraft.

Location data

AIRCOM Server is SITA’s airline operations center system developed originally to manage communications with the ACARS systems in their aircraft. Many airlines already have it in place.

It displays the aircraft’s location based on information coming from systems within the aircraft itself. It also shows the aircraft’s location from reports generated in response to requests from and radar surveillance data feeds sent by air traffic control (ATC).


One of the systems that airlines already have for flight tracking is the future air navigation system (FANS). Developed in the 1980s, it’s currently on roughly 4,000 long-haul planes and is standard on all new Airbus and Boeing aircraft. It’s also becoming mandated for ATC purposes.

ATC computers can request position data from the aircraft FANS every ‘X’ minutes – it could be five minutes, or 10, or 20; the number is configurable, with conditions and parameters set by the ATC.

It can also request position data whenever the aircraft changes route or altitude. This information is essential for ATC, but it isn’t currently used for airline purposes. Airlines can access this data that goes via the SITA AIRCOM network.


The FANS system was designed to be used in oceanic airspace where ATC previously only knew aircraft positions when they received pilots reports via HF voice radio.

This was so unreliable that ATC had to keep the aircraft far apart and could not allow them change route to avoid bad weather or take advantage of tail winds.

It has meant that the first ATC agencies to deploy FANS ground systems were those covering oceanic airspace followed by ATCs covering remote continental airspace not covered by radar.

Today, only 50 ATC agencies have installed FANS computers, which are expensive – they can cost tens or even hundreds of millions of dollars, depending on the scale on the ground.

Fifty out of approximately 150 ATC agencies worldwide doesn’t mean that only one-third of the world’s surface is covered. The Pacific Ocean, for example, which is roughly half the world, is covered fully.  There are also areas where airlines can access the ATC radar data making the use of FANS unnecessary, specifically the US domestic airspace and the Eurocontrol area.

But there are many areas where it would be useful to have this coverage, and where ATC hasn’t yet implemented these FANS systems.

Way ahead

SITA is establishing a way for AIRCOM Server to identify when reports are coming from ATC-generated messages and when they stop, and also a way for them to request the reports proactively. So the airline system can be programmed to use the same interfaces that ATC systems use.

SITA sells these ATC systems, so we have the expertise to transfer them into the airline system.

It’s not a simple process. The AIRCOM Server ground system needs to implement the interface to FANS avionics that had to be defined specially to enable ACARS text messaging to support the ATC applications whose exchanges are not limited to text. .

Once it’s done, so long as the aircraft systems are on and the airline chooses its configurations, it is possible for the airline to get the position of the aircraft practically from takeoff to landing.

Capturing the unexpected

One of the most important aspects in developing our system is to identify unplanned aircraft movements. If flight dispatchers are given alerts every time an aircraft changes direction, they’ll stop looking at the system and ask that it be switched off.

By identifying unplanned movements, dispatchers can exclude the ones they know about and focus on those they don’t.

Because SITA has access in our network to ATC datalink communications with pilots, we’re able to identify when ATC has sent an instruction to the aircraft, telling it to change direction or altitude.

This provides many capabilities that would be unavailable if the system was operated by a third party that didn’t have access to such information.

Intelligence opportunities

The tracking part is relatively easy. But the intelligence on top of it – identifying when something goes wrong, differentiating it from normal behavior – is challenging. It’s the ‘needle in the haystack’ that occurs maybe once every five years.

SITA views this challenge as an opportunity to do something for the community, perhaps avoiding mandates which could require costly new systems. Why not take what’s already there and put it to full use?

We’ve already started tests with selected airlines, looking at AIRCOM Server’s capability. We hope to share the results of these tests by the end of the year.

SITA remains committed to identifying how we can make the best of what we have and supporting the industry in any way we can.

Flight tracking task forces

The catalyst for SITA’s Flight Tracker solution was the International Civil Aviation Organization (ICAO) Special Meeting on Global Flight Tracking of Aircraft held in May.

One conclusion of that meeting was that airlines were encouraged to use existing equipment and procedures to the extent possible to support flight tracking.

The meeting resulted in the development of a Task Force led by both ICAO and the International Air Transport Association (IATA) to further evaluate possible solutions to enhance flight tracking. SITA will make its airline tracking solution comply with any ACARS based solution determined by the Task Force.

SITA provides over 150 airlines, flying more than 10,000 aircraft, with communication services for their Aircraft Communications and Reporting Systems (ACARS) cockpit data link systems through its global AIRCOM network. This network consists of 1400 VHF radio stations and links via satellite.

India's drive to embrace aircraft tracking

Members of the Indian airline community came together earlier this year to learn about advanced aircraft tracking at an Aircraft Services Workshop held in New Delhi.

Attendees at the workshop – jointly hosted by SITA and the Indian Government’s Directorate General of Civil Aviation (DGCA) – included leaders and executives from all major airlines and airports in India.


The workshop’s inaugurator, Shri Ashok Lavasa, Secretary, Ministry of Civil Aviation, said:  “SITA has provided Indian airlines a great opportunity to discuss the global standards and developments in aircraft tracking mechanisms.

“With its growth in passenger traffic and new airlines and airports, the Indian aviation industry has the potential to become one of the top three globally by 2020. Adopting global standards and leading the way in important areas such as aircraft tracking will cement India’s leading position...”


The DGCA has made it mandatory for airlines and private operators to use all means to track their aircraft flights on a real-time basis and ensure that necessary devices are functional before take-off.

Delivering the keynote address, the DGCA’s Director General, Dr. Prabhat Kumar said: “Tracking of aircraft on a real-time basis is one of the biggest needs of the industry today not just in India but across the globe.

“This calls for robust technology that will work with existing systems to make it more efficient and most cost effective. I hope that initiatives like this joint workshop with SITA, providing valuable information on tracking solutions, will enable Indian carriers to move ahead in this important area.”

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