I wanted to know more about the mysterious language. A Wired article from last year gave a few hints, along with the amazing Tumblr Holding Pattern. And it turns out that the Federal Aviation Administration keeps public guidelines for all of these design elements online. After digging into the FAA’s list of documents and exploring in Google Earth, this is what I found.
The LinesAs a passenger, it feels like most pilots try to come down as close to the edge of whatever seems to constitute runway as possible. That’s definitely not the case — there’s a language of lines and indicators that helps pilots time their touch-down at the exact right moment. Most runways at major airports follows the same pattern, defined by the FAA’s advisories on runway markings, found right here as a PDF.
First, there’s something called the blast pad: A patch of what looks like runway, painted with yellow chevrons or lines, that’s actually often not strong enough to hold the weight of the plane (“Your gear may poke through the runway!” exclaims one virtual training primer). It’s never driven or landed on, but it still serves an important purpose, since it’s designed to prevent the “blast” of departing jets on the runway from creating bare or eroded patches on the soil just before the runway. Basically, it’s a runway band-aid, as you can see here at LGA:
The Numbers, Colours and Signs
So, who decides on a typeface? Again, that would be the FAA. All letters and numbers have to adhere to its careful guidelines, which include everything from the carefully-proportioned dimensions of the characters to the “1″ with a horizontal tip to avoid confusion. All characters have to be 60 feet (18.29m) high, except 6 and 9 — which can be 3 feet higher because of the tails:
One of the things I was always curious about were the red square signs that seem to dot every runway. It turns out those are a bit like stop signs — the FAA says they indicate the “holding position” for a plane that’s waiting to take off or get to the gate. The numbers are there to help the air traffic controller coordinate the comings and goings.
Update: Gizmodo reader TheHeadFL writes with more info about these marks: “Most of the red squares you have pictured are actually for the benefit of the pilot, not really ATC. When you get to the hold short line at a runway entrance, the red block will denote which runway you are about to enter. For example “18-36″. Runway 18 runs from left to right, and Runway 36 runs from right to left.”
Which brings us back to the thing that sent me down this weird FAA standards rabbit hole: The lights. Though Dubai’s new lighting system is comparatively new-fangled, it still adheres to the same language as most runways.
As you look up to see the runway or approach light environment, you must, by default, take your eyes off the attitude indicator. If it’s dark, rainy or snowy, (or the kids in back have their hands over your eyes), you may have difficulty identifying the lateral (bank) cues necessary to keep the aeroplane flying straight. The decision bar’s horizontal spread of bright white lights acts like an external attitude indicator, providing you with visual bank references as you seek other runway cues.
Which brings us back to the original reason I got curious about runway lighting: The increasing use of LEDs on runways. While Dubai and many other airports have switched over to LEDs — citing efficiency, durability, and even visibility — not everyone agrees they’re better. Stateside, some pilots havecomplained that LEDs are blinding and causing problems during landings.
I asked a commercial airline pilot named Chris Manno, who runs the blog JetHead, about the phenomenon. Manno had a completely different take on LEDs. “I’ve heard that, but I don’t agree,” he told me.
“It can be a little bit of an annoyance, but it doesn’t cause a problem, and in fact, I think they’re an improvement over the old lights.” Manno says that the lights are brighter in foggy conditions, and they make it much easier to find the runway. “We’re starting to convert the aircraft landing and taxi lights because it’s so much better,” Manno added.
When millions of flights from hundreds of countries take off and land every month, developing a standard vernacular that every pilot can read is absolutely crucial. So yeah — it’s just a bunch of lines and numbers. But it’s also the vernacular that helps keep you, and everyone else, on track.
source: gizmodo.com by KELSEY CAMPBELL-DOLLAGHAN