Airport Science

Hullo, hullo PaleoPosse… *yawn*…

I’m sitting at Orlando International Airport right now, trying to sneak onto a flight that might have an empty seat, and I figured I’d brighten your day and mine with a little bit-o-AIRPORT SCIENCE!!

Incheon International Airport in South Korea

 

I’ve told you before how Jet Engines work, and how Stealth Technology works, so today I thought I’d give you a quick lesson on how airports work, from the pilots’ perspective.

A quick disclaimer before I begin.  I am NOT a pilot, so I may get some of the specifics wrong.  But I have flown with friends a few times, and I am an airplane enthusiast *SNORT*.

A Brief History of Space and Airports

The exact identity of the “first airport” is disputed, as the first few years of aviation consisted of taking off and landing from a grassy field (or a dirt field if you were lucky), but most aviation historians agree that the first airport was established in 1909 at College Park, Maryland. At this time, airports served as simply a place to safely land your aircraft, and to tie it down afterwards.  Over time, hangars were added to provide protection from the elements…then flight training schools decided to locate on-site, as aviation was in it’s early days largely a hobbyist’s field.  Eventually commercial aviation “took off”, and airports began to take on an entirely different role; one in which large masses of people needed to be “herded” and guided to the proper planes, hopefully with their luggage.  In the 1970s the risk of malicious passenger attacks on commercial airlines became apparent, and airports again adopted a new role: preventative security for the airlines.

"Sir, is this item dangerous?" "Um...sometimes?"

 

And finally, as commercial aviation expanded even more, individual pilots could not coordinate amongst each other whose turn it was to land, so airports began to take on yet another new role: skyway traffic officer, which created the field of Air Traffic Control (ATC).

Cartoon example of ATC out of San Francisco

 

Air traffic control combines radar sensing, radio communications, 3-dimensional velocity calculations, psychology, communications, safety science, and emergency response studies into a single, high-stress/high-reward job.  Planes are routed into flight paths depending on where they are going, how many planes are in the air, and how many planes are about to be in the air.  Needless to say, air traffic control is extremely necessary in modern airports, as it provides organization to air in the same way that roads and stoplights provide organization to automotive travel.

And where the the job of the Air Traffic Controller ends, the job of the airport designer (a subset of Civil Engineering) begins.  Whereas airports originally only needed one, maybe two runways (to account for different wind directions), modern airports often require multiple runways in the same direction to allow for multiple simultaneous landings. Each runway is preceded by a fun little array of lights known as the Visual Approach Slope Indicator, or VASI.

 

The downstream VASI is circled in red

 

The VASI consists of two separate arrays of lights, one before the runway and one slightly after the runway (approximately 7 meters).  The lights are filtered in a fashion that makes them look white from some angles, and red from other angles.  The pilot uses this to ensure that the plane is on the proper “glide slope,” or the curve that the aircraft traces out in the sky during landing.  Ideally, the first set of lights should appear white and the second set should appear red.  If the pilot is coming in too high, both lights will appear white.  If the pilot is coming in too low, both lights will appear red.

This is a somewhat “old school” approach to navigational assistance. Though it is still the primary method of “feeling out” a landing, modern solutions can utilize high-precision radar or GPS to help guide the pilot (or auto-pilot) to a safe landing.

Speaking of auto-pilot… Did you know that your plane really doesn’t even need a pilot anymore? Though pilots are typically required to take off and land manually, modern aircraft control systems are fully capable of operating most aircraft, most of the time.

 

Prepare for warp, Number One. Engage.

 

Traditional auto-pilot systems are simple 2-dimensional control systems that do little more than “steer” the aircraft towards it’s destination.  Originally, this only involved usage of the rudder, while relying on the aircraft’s inherent aerodynamic stability to keep it level during turns. Eventually auto-pilots evolved to include aileron control to allow banking turns, and then into pseudo-3-dimensional systems which controlled cruising altitude as well. This is how auto-piloting remained for quite a while.

Up until recently, the aviation community was hesitant to attempt to “program” an aircraft to land itself. Taking off is simple enough – but landing is an entirely different story. There are just so many variables to take into account: instantaneous wind direction, current fuel levels, payload weight, length of runway, visibility, humidity, temperature, the position of the control surfaces, etc…  To pilots, a good landing is as much about “feeling” the air conditions as it is the responsiveness of the aircraft. To imagine a computer program that could replicate that sense and complex critical thinking is something that was unthinkable a few decades ago.  But today, ladies and gentlemen, is the future.

 

N-UCAS rendering on an aircraft carrier

 

Are you ready for this, plane-o-phobes? The commercial airliners that you’ve been flying on for the past decade are completely capable of landing themselves. Lucky for you, most airlines don’t allow auto-pilot landings except for certain, rare situations.  Also, pilots are hesitant to allow a computer to take over another aspect of their job.

So although you likely won’t see completely unmanned commercial airliners anytime soon, UAVs have been making completely autonomous landings in severe and varied landing conditions for over an entire decade now. The Global Hawk flew completely autonomously from LA to Australia in 2001! And today, we have in development no less than 2 separate unmanned systems capable of landing on an aircraft carrier (which, even today, is still really freakin hard).

So next time you’re sitting around in an airport, pissed off that someone stole your seat at the gate, or stressed out because your flight is delayed, maybe you can look around and appreciate just how far we have come since the Wright Brothers, and maybe see some of the hints at where we are headed in the future.

Stump – Out.

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About Jacob

Jacob likes airplanes. And Lego's. And Video Games. Jacob has a degree in Aerospace Engineering from Embry Riddle Aeronautical University, and now works for a major defense contractor in sunny Florida, as an aircraft structural analyst.

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