Navigating Taxiways Is Trickier Than You’d Suspect, but New Tech Can Help

July 19, 2017 | Author: Nate Turner

As you settle into your seat and prepare for takeoff, your pilot is often navigating the equivalent of rush-hour traffic. Getting from the gate to the runway — especially at the world’s largest airports — can be more complex than you think. Mix up a letter or a number, and you could clip a wing in the blink of an eye.

As you back away from the gate, your pilot hears a voice over the radio: “Dot-Com 26-32 taxi to runway 1-8 left via Juliet-Yankee, Zulu, Hotel-Yankee, Hotel, Whiskey-Foxtrot.”

Although that might sound like gibberish to the untrained ear, traditionally that has been the best way for pilots to know where they are headed to ensure a safe takeoff. After hearing the guidance from air traffic control, the crew checks the instructions against their airport map to verify the route, and repeats the instructions over the radio. Next, the captain moves the thrust levers forward, and you’re off to your destination.

There’s more technology available than ever to ensure a safe and efficient trip from the gate to the runway, but first let’s examine what all those numbers and letters on taxiways actually mean.

Let’s start with the airport diagram from Dallas-Fort Worth, below.

Nav  Figure 1 Taxi Instructions at Dallas-Fort Worth

From the Alpha terminal, those instructions (the blue arrows in Figure 1) told the crew to taxi the aircraft along “Juliet-Yankee” (JY on the chart), “Zulu” (Z), “Hotel-Yankee” (HY), “Hotel” (H), and finally “Whiskey-Foxtrot” (WF). The crew would then taxi (pilot lingo for driving on the ground) along the route until stopping just before the runway 1-8 left. The 1-8 indicates the magnetic heading the runway is pointing, in this case 180°, while the left shows that there are multiple runways.

Confused yet? Let me try to make it a little simpler.

Just like when you’re driving around town using street signs as reference, pilots use the airport signs and markings around the airport to taxi. Next time you’re on a flight and taxiing at the airport, look outside and check out the signs and markings. Those tell pilots critical information on where they are on the airport, information on a taxiway/runway, and a whole lot more. Crews can look out to the signs located by each taxiway to see which one they’re on (black background and yellow lettering) and which way the taxiways intersect (yellow background and black lettering). Signs with a red background and white lettering indicate a runway is ahead.

Nav  Figure 2 Various Taxiway Signs

When pilots approach a runway, they’ll see two solid lines followed by two dashed lines running perpendicular to their path. This indicates a “hold short” bar and tells the crew they need permission from ground control to proceed. Sometimes, runways will have an instrument landing system (ILS) “hold short” line that crews will have to stay behind if the ILS is in use.

Nav  Figure 3 Hold Short Lines

When pilots taxi out to a runway, they’ll do a verification of the runway a few ways. First, by checking the magnetic heading on their forward displays, and another by viewing the large letters painted on the runway. As pilots take the aircraft to the sky, there are even more indications that they can use on the runway.

Nav  Figure 4 Runway Markings

While this barely scratches the surface of all the airport signs and markings that pilots use, this should give you a little more insight into what crews have traditionally used to drive aircraft on the ground.

But even with everything I’ve mentioned above in place, there are improvements to be made. New technologies from Honeywell help pilots like myself ensure taxiing is even more safe and efficient. For example, the Runway Awareness and Advisory System (RAAS) is already available in Honeywell’s APEX® and EPIC® cockpits. This system alerts pilots if they’re approaching or on a runway by speaking the runway name, allowing them to hear the runway and focus on important tasks like driving the plane.

Another technology available in the cockpit is our 3-D airport moving map, which allows pilots to see a rendering of the taxiways and runways with identifiers on their displays. This greatly reduces the guesswork of figuring exactly where they are positioned at the airport and what’s ahead, as shown in the figure below.

Nav  Figure 5 3D Airport Moving Map

As you can see, this moving map provides a much better view than any pilot can have while in the cockpit. That map combined with RASS can help prevent the sort of near-misses we’ve seen of late with actor Harrison Ford landing his small plane on a taxiway early this year, and an Air Canada A320 jet nearly doing the same in San Francisco last week.

When you push back from the gate on your next flight, remember that your travel on the ground is just as important — and a heck of a lot more crowded — as when you’re in the air.

Nate Turner

Nate Turner

Turner started flying as a teenager and went on to earn an aviation management degree and CFII and MEI certificates flying primarily Beechcraft Bonanzas and Barons. Turner is a flight instructor and was also a pilot for American Eagle Airlines as a first officer on the ERJ 135/140/145. Turner joined Honeywell in 2013 and has held multiple roles and responsibilities in helping the company develop next generation avionics and innovative pilot services.

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