How many of you know what EMAS is? I can guarantee that the 34 people on a US Airways Express jet in Charleston West Virginia now are intimately familiar with it. It prevented them from plunging off a mountain. This mountain. Seriously.
EMAS stands for Engineered Material Arresting System – a name only the government could love. Think of it like a runaway truck ramp. You know what I’m talking about. When you’re coming down a mountain and you see those gravel strips on the side where trucks can go if their brakes fail? (For those of you in the Midwest, a mountain is something you’ve probably seen on TV.) But EMAS stops airplanes, not trucks, so it requires some more strength.
You will find an EMAS in 28 airports today; the first was installed at JFK in 1996. How do they pick the airports? Airports in the US are required to have overruns called runway safety areas (RSA) that are 1,000 feet long and 500 feet wide, at least. (Many advocate for more.) There’s only one problem. Many airports were built before these rules went into place, so they don’t have the room. Those airports have been getting EMAS.
Remember the Southwest flight the went off the runway and parked at a gas station in Burbank in 2000? By 2002, Burbank had an EMAS. And that brings us to our buddies at Charleston, West Virginia, better known by many as Charlie West. Charlie West sits on a mountain (as you saw above), and in 2007, the feds decided it might be a good idea to keep planes from sliding off the end. Good thing they did.
Earlier this week, a US Airways Express 50 seat regional jet operated by wholly-owned PSA Airlines rejected its takeoff. It couldn’t stop quickly enough and it ended up off the runway. Thanks to EMAS, the plane didn’t plunge off the end of the runway. Brian Belcher and the rest of the team at Charlie West have been doing an excellent job of keeping people up to date via Twitter and Facebook. (I wrote about Charleston’s expert use of social media on BNET.) They posted this picture:
Holy crap. Now, the plane has been moved, the airport is back to normal operations, and all they need to do now is fix the EMAS so it can do its job once again. Talk about a great invention.
It’s a great invention and I’ve seen it tested on a TV show. The only thing is until it’s rebuilt/fix/repaired, could it still stop another plane if need be?
For that airport maybe they need one of those cable systems like aircraft carriers use. All planes would need a hook installed underneath to grab it……lol
You can see the “arrester bed” when driving past LGA Airport. Looks like multiple square cement blocks. (as shown in the picture)
Ehh, Scuse me for asking but I am from Philly and I just don’t get why you’d build a runway that ends in steep cliff in the first place?
Cause in West Virginia your choice isn’t whether to build on a mountainside or not, the only choice is WHICH mountainside. :)
When you look at the airports all over this country, how so many of them have such potential for an overrun disaster because where they were built, it’s a real testament to the people who make our airliners, the mechanics who keep them running, and the pilots who fly them, that there are so few of these overrun events.
Just about any airport in W.Va, and the mountains of Pa., are built with a huge runway end dropoff. Check the Wilkes-Barre/Scranton airport at Avoca. Or, out West, try St. George, Utah. Actually, when you look at Wahsington-National, San Fran, LAX, San Diego…wow! And, yet, things seem to keep going, but it’s nice to know there’s something like EMAS, just in case.
For a time I was flying into SFO every two weeks. I’m not one with a fear of flying, but when we’d come in for a landing, I’d think, “Don’t undershoot, don’t undershoot, don’t undershoot, don’t undershoot…” Seeing the water of the Bay rushing up to meet you and then suddenly LAND-HO! (THUNK) was sort of surreal.
Without Googling, cause I’m lazy, are systems like this capable of stopping a jet larger than an RJ, though? I can’t imagine the g-forces those in the cabin go through when decelerating a plane that quickly, even if by the time it gets to the EMAS it’s not going that fast.
David SFeastbay wrote:
Yeah, I mean, they’ve announced that it’s out of service, but the RJ didn’t use it all. So there is still going to be some stopping power. They are already getting workers out to figure out how to get it rebuilt quickly.
And it’s been done before (granted a long time ago):
LAX actually isn’t in the same boat at all. It’s a nice flat approach into the airport from the east. And on the west side, there is still a fairly good buffer before you hit the dunes on the coast. The water isn’t the biggest issue.
Absolutely. If you click on that EMAS link toward the top of the post, you’ll see that an MD11 and 747 have both been stopped at JFK.
from what I have heard…its very expensive….close to 2- million per threshold…
When I used to live in Binghamton, the only space they could find large enough and flat enough for a commercial airport was the leveled off top of a pretty big hill.
Pilots said it was like landing on a table top….
If you have access to the archives, it was a BATTLE, and a HEATED ONE… everyone screaming over the cost and how it is such a waste of tax payer dollars.
would be nice to find those anti-airport folks now and introduce them to 34 people.
We’re overjoyed that there were no injuries in the incident and that the aircraft wasn’t seriously damaged. The EMAS worked exactly as designed and we couldn’t be happier for this.
Thank you CrankyFlier for the article about us!
– Yeager Airport
This family of one of the passengers is also overjoyed that there were no injuries! Those 34 passengers are people who touch and will touch countless other lives in many different ways. A worst case outcome would have impacted an exponential number of people along a continuum of “what a shame” to “devastation!”
I’m sure you’re much happier than any of us! Any chance you can ask your family member what it felt like when they hit the EMAS? I’m curious what the sensation is like.
Can someone explain why it can’t just be a gravel bed? I don’t get why it has to be an engineered surface.
What type of stopping power does gravel have vs something that will crush instantly and absorb all of a moving objects energy?
I too wonder what the deceleration of the EMAS feels like. I’m not sure the passengers knew they were stopped by an arresting system given some of the comments on the news and in the paper. Everyone said they hit the brakes fro a while and then they REALLY hit the brakes.. which I’m guessing was actually the EMAS portion of the ride haha.
Does Canada think about EMAS systems? Might have helped that Air France A340 that badly over-ran its landing (in ridiculous rain conditions) at Pearson International (Toronto) and ended up in a ravine, destroyed (but no casualties, in one of the industry’s miracles).
My husband described the hard braking while on the runway. When they hit the EMAS, it was a rough ride, like they’d run off the end of the runway, more rapid slowing and a sudden, hard stop. Not sure I can accurately depict the sound he made in text, but imagine a low pitched “WHOMP!” LOL!
CF, come now — I’ve come to expect great journalism from you, it’s why I come to this site — you always give a balanced view and provide plenty of background info for everything you write, to put it in context. So now : do tell us, how much of the EMAS did the plane use, and given that distance and comparison with other similar excursions, can we do any analysis to find out whether or not the plane might have stopped anyway if the EMAS had NOT been installed (the area presumably having been surfaced as a regular runway pre-EMAS installation)?
I’m not questioning its use at all — I think this is a fantastic invention — but I think it’s worth looking at this particular incident more closely to see what we can learn.
Also, as for airports being worthy of EMAS, I nominate OAK.
Unless I’m reading this wrong — before the EMAS was installed, maybe this was just a vegetated area? I don’t know. Can you give more info?
Also, why did this plane abort so late? Do we know? This is an atypically skimpy entry!
the land the EMAS is on did not previously exist. The slope of the hillside previously started about 100-200 ft. from the runways edge.
YYZ does not have EMAS, despite the ravine at the end of the runway that the AF flight went down, and an AC flight in the late 70’s. I can’t think of any airports in Canada that do have it…
@ David SFeastbay:
There is still a significant length of EMAS in place. It could stop another similar event.
EMAS has already stopped a B-747 at JFK.
Gravel gets saturated and freezes in the winter.
It feels like very hard braking. About 1G deceleration.
You have to keep in mind that before the EMAS was installed at CRW, the area was air. There was a huge earthwork project just to provide some ground on which to install the system. Even if the area had been subsequently paved, it would not have stopped.
@ Nicholas Barnard:
Binghampton is sloped too
EMAS will stop anything that is a certain weight above its crush weight. Im glade I’ve never had to use it but I’m also glade it’s there.
Arrrrrrrgggghhhhh! You just hit my biggest pet peeve about the commercial airline industry: an inability to pronounce and spell lesser known cities correctly. It’s Binghamton, no P!!
I’ve heard one too many USAir and USAir Express flight attendant stumble over this name. It’s pronounced like it’s spelled Bing-ham-ton.
@ Nicholas Barnard:
So, My wife’s parents can’t pronounce our last name, i could care less about a city i fly into twice a month
The plane stopped appx 250 feet from the edge. Without the EMAS, it would have kept going.
Also, CrankyFlier did not say why it was aborted, because the FAA is still investigating. It’s not exactly being “rushed” because it was an incident, not an accident because there were no injuries.
There are approximately 4400 EMAS blocks at CRW. The plane “used up” 240 blocks. They will hopefully be replaced within the next week, however, the temperatures have to be above freezing for the material to be installed.
I think CF did a great job with this post. There wasn’t much information available for him when writing the article. He did a great job with what he knew!
I think most of your questions have been answered very well by other readers. Not sure why you think this is a skimpy entry. We don’t know why the plane aborted so late but that’s not the point. This is about EMAS, and while I don’t know for sure, it seems quite clear that there would have been at least significant injuries were EMAS not installed.
I do know for sure. There would have been 34 bodies and a twisted pile of metal.
No offense but duh, WV is all mountains and you pretty much have to build on the mountain top. :-)
I came home to CRW on this plane. It had a good experienced crew and I’m sure they made the right choice. I am very thankful for EMAS and that everyone was safe. I could have just as easliy be going out on this plane instead of arriving.
There is still a significant length of EMAS in place. It could stop another similar event………
I’ve seen topdressing pilots here in New Zealand using hilltop strips where they routinely leave the end of the short strip heavily loaded with insufficient airspeed to climb. They know there’s plenty of air for them to drop into where they can build some speed before climbing out of valley. Just sayin …