Airports can be busy, complex and confusing places - and not just for passengers - but to airliner crews themselves attempting navigate around unfamiliar terminals. TIM ROBINSON reports from a recent RAeS Heathrow Branch Lecture on improvements coming to onboard ground navigation systems.

It is a paradox that the most highly automated bit of being an airline pilot these days is actually the most fun part - the ‘flying’ bit and the freedom of piloting an aircraft through the skies. Meanwhile, one of the most stressful, yet routine tasks, that of taxiing around an airport to and from a runway remains firmly a manual operation and essentially unchanged for decades.

In the meantime, airport hubs have grown like topsy, becoming ever more complex and busy, with additional taxiways, signage, multiple gates and at many airports, ongoing construction projects or temporary restrictions.

The result is that even for experienced pilots with the latest paper of electronic maps, navigating around an airport can be a disorientating experience - made worse by weather conditions (eg: fog), time of day (night or bright reflections in sunrise/sunset), confusing signage, or temporary restrictions - as well as having to take and understand directions from the ATC tower.

It thus seems incredible that today, a modern airliner, equipped with the latest in navigation systems and avionics and able to autoland in zero visibility, taxiing around an airport in poor visibility, the crew might well be reduced to counting off the taxiways using their fingers to find the correct turn-off.


runway incursions now are running at two a day in Europe and four a day in the US"

But new technology is on the way to help. Giving an overview of the problem, solutions and future of airport navigation to a RAeS Heathrow Branch lecture in March were Pierre Carpentier (Product Line Manager Avionics Functions) and Olivier Frerotte (Design Authority, Airport Operations Functions) from Thales Group.


Accidents and damage

Dubai Airport uses a 'Follow the Greens' lighting system to help pilots navigate on the ground. (GCAA) 

Getting lost at the airport, is not just a matter of pilots’ bruised egos but can have safety and economic implications. While airlines have continued to maintain their outstanding safety record in the skies in recent years due to training and the latest equipment the upshot has been an increased focus on ground movement risks and incidents. The vast majority of these never make the news but the consequences, as in the  world’s worst aviation disaster in Tenerife in 1977, can be fatal. Setting out the wide scale of the problem at the start of their talk, Carpentier and Frerotte noted that runway incursions now are running at two a day in Europe and four a day in the US. In addition, they observed, ground safety mounts up, with damage on the ground (clipped wingtips, collision with baggage trucks etc) costing airlines approximately $4-7bn a year.       

To improve navigation around busy airports, various solutions, both onboard and offboard, have been implemented or suggested. Taxiway lights, controlled by ATC are one system in use at London Heathrow and Dubai and rely on the aircrew to ‘follow the greens’ to reach the gate or runway. However, as well as a ground controller it also requires a lights operator, increasing manpower requirements for the airport. It thus will not be available at every airport. Another off-board solution mooted in recent years has been the Taxibot - a fuel efficiency system designed to tow airliners to the runway automatically before they start their engines. While low-fuel prices has meant that the Taxibot concept has so-far failed to take-off - it would also not aid the crews situational awareness themselves. 


Enter the moving map

Onboard moving maps bring increased situational awareness to aircrews. 

A third solution, and rapidly gaining popularity, is the onboard moving map which Carpentier and Frerotte both work on for Thales. First introduced a decade ago on the Airbus A380 in 2007, the integrated airport map, (whether produced by Thales or its competitors) has now become standard on new airliners and top-of-the-line bizjets. In the latest Thales version on the A350 XWB, for example, a trackball allows pilots to zoom in and manipulate the display. Interestingly, one sector unrecptive so far to airport navigation moving maps has been regional aircraft - perhaps a reflection of the smaller, simpler airports that regional airlines operate from. 

Of course, we all have GPS devices in the form of smartphones and tablets - so why not just use Google Earth? Carpentier and Frerotte revealed that the high standards demanded by the aeronautical industry means a cockpit moving map must have accuracy far beyond a consumer device. For example 5m accuracy was required and the airport database updated every 28 days. The latency effect too meant that the moving map avionics uses both GPS and the aircraft’s inertial navigation to achieve 3-5m accuracy. For aircraft navigating narrow taxiways or positioning at large junctions, this high accuracy is vital.  


Leveraging consumer tech


Video showing the latest Thales TopWings EFB moving map features (Thales)

For older aircraft lacking the inbuilt airport moving map avionics of the A350, A380 or 787, one obvious solution is to put moving map functions onto EFB (electronic flight bag) device. This approach, leveraging the latest consumer tech of tablets and smartphones allows for a low-cost, rapid development retrofit solution. Thales, under its TopWings EFB, includes the Thales Pad, based on a ruggedised tablet. However, for EFBs vs inbuilt avionics there can be drawbacks - such as awareness only, it being limited to a cockpit side display (instead of a larger central MFD) and integration with avionics functions.   

At the lecture, Carpentier and Frerotte also showed off the newest version of Thales’ moving map technology integrated with TopWings and outlined future enhancements. In particular, the latest version, launched last year, takes its cues from smartphone and tablets in the way in which pilots interact with it with ’pinch and zoom’ touch controls. As well as the top-down view, a new 3D view tilts the view into a forward arc, above and behind the aircraft, enhancing the crew’s situational awareness. On a touchscreen display, pilots can now search for gates or taxiways with a ‘autocomplete’ style text search function. The moving map now includes automatic or manual taxi routing functions - with the user able to change the taxi route by dragging a finger on the screen to adjust the route - without having to type in new taxiways.

As well as the in-built airport database of obstacles, buildings, gates and taxiways, the new moving map also allows crews to enter their own annotations on the map, for example warning of temporary obstacles or hazards - an extremely useful function for the next crew to fly to that airport. Conveniently, the EFB can now have up to four airport tabs open at the same time.   

Future enhancements

D-Taxi would provide a datalink exchange for airliners during taxiing and ground operations. (Eurocontrol)

Beyond this, future evolutions of airport moving map technology will see technology already in use in the air (such as datalink CPDLC and ADS-B tracking) introduced to cover the ground segment of operations too, allowing for a seamless environment. Datalink taxi routing (D-TAXI) , for example, will see clearances and taxiing routes sent by ATC to the aircraft’s moving map directly, with the pilot only having to approve a route. This will cut down on voice transmissions - often the source of errors themselves. This has already been tested under the European SESAR initiative. 

Meanwhile, incorporating ADS-B air traffic on the ground will allow for increased situational awareness and help prevent runway incursion tragedies such as Tenerife. Equipping airport ground vehicles too with ADS-B would also providea  huge boost to crew’s awareness.

Finally, Carpentier and Frerotte revealed that airport moving map guidance would also most likely be coming to airliner HUD (head-up displays) in the future. With Thales already providing HUDs for airliners such as the A350 XWB, integrating airport navigation with extra symbology to give a ‘virtual follow the greens’ line would enhance situational awareness by allowing the pilots to keep eyes out of the cockpit.     



Graeme Catnach, RAeS Heathrow Branch Chairman thanks the speakers for their insightful lecture.

This sort of moving map technology (which ironically car drivers take for granted these days with SatNavs), is a welcome step in moving ground operations into the 21st century. Old and bold pilots might argue that at many airports, experience and current signage is adequate to prevent getting crews getting lost. However, there still remain a worrying number of minor incidents, from collisions with ground vehicles, clipping buildings (or other aircraft) with wingtips and runway incursions that any improvement in situational awareness is a benefit - particularly as airports get bigger, more crowded and more complex.    

The lecture was rounded off by a Q&A session which, given its location (BA’s Waterside HQ) led to some extremely knowledgeable questions on the subject from local RAeS members. It also highlights a key strength of the RAeS in the local Branch’s ability to attract expert and knowledgeable industry speakers. Go attend your next local RAeS Branch event!

Tim Robinson
21 April 2017

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