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Tuesday, September 3. 2013The Asiana crash, revisited The reason that was given was, due to some confusion in the cockpit, the autopilot was assumed to be taking care of the aircraft's speed, which it wasn't. So, they lost altitude quickly at the end and clipped the edge of the runway. But that doesn't really answer why the pilot was trying to land so near the edge of the runway in the first place, what with a long, expansive landing strip in front of them. And this is especially true in S.F., where there's no pre-runway to safeguard against such things, because the runways jut out into this big watery thing called a "bay". But upon watching the following video, pointed out to me by my buddy Feebs, I was suddenly reminded of a nasty experience I once had, which might just answer that elusive why. For airplane buffs, this is a very interesting video showing the last number of minutes of an airliner landing at SFO from inside the cockpit. A few things to watch for: — I like they way they label it "Silicon Valley, CA". Silicon Valley is a euphemism for an area loosely composed of parts of San Jose, Santa Clara and Sunnyvale. — Since we presume they didn't do any editing-out in this thing, both the 'Landing' and 'Shutdown' check lists are stunningly short. — There's an interesting moment when the computer calls out "200" feet, and it appears the pilot actually has to give it the verbal command to "continue" for things to progress as normal. I presume he's actually talking to the co-pilot, following routine, but you'll see what I mean about it appearing like he's talking to the computer. — It's also interesting how bouncy the cockpit is once they touch down. You don't get that feeling at all from the rest of the plane, but these guys are seriously a'shakin'. — And how in the world do the pilots see those baton-waving directional guys way down on the ground? For the final 'stop' command, do they raise some guy way up on a crane in front of the cockpit? Well, not exactly. What they're going to do is fly in high over S.F. heading southward, go down to the South Bay (Silicon Valley), turn around and head back up to the airport over the bay.
It was at San Carlos airport, mid-way down the Peninsula, and I was being given a demo ride by an instructor. I was about 30 or so, had just come into a small inheritance, and wanted to fulfill a lifelong dream of getting a pilot's license. We took a Cessna 172 up, up and away, flew over the coastal range that runs down the spine of the Peninsula, cruised out over the Pacific, did a few basic acrobatics, and headed back home. And there was the edge in front of us, and the pilot came in low, over water, aiming for the very rim of the runway. At the last moment, I was 99.99% positive we were going to hit it with the wheels, cartwheel over and die. Whoomp! We landed safely and I immediately (1) signed up for lessons with (2) the condition that it not be that guy. It honestly scared me like I've seldom been in my life. And just why was he trying to get so close to the edge, when there was figuratively miles of runway in front of him? Because getting close to the edge was the only challenge in sight. In my Culture in the Cockpit post, I noted how sometimes airline disasters can almost be directly attributable to countries with militaristic backgrounds whose Air Force pilots then turn to commercial aviation, and how that "don't question authority" mindset can often be their undoing. But this is different. Place yourself in the Asiana plane, as a junior pilot wanting to impress his superiors by just nailing that edge. Except that this time the autopilot doesn't have your back. This wasn't a cultural crash. This might have been nothing more than pride.
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That was damn interesting. You might be on to something. I suppose we'll never actually know, but trying to "nail the edge" sounds more plausible than anything else I've read. As you mentioned, this also infuses carrier pilots, so it's not something unique to one branch of aviation.
The vid was great, too. And you're right about the two check lists being amazingly short. I looked for a cut in the editing and didn't see anything apparent, plus you'd also have to wonder why they'd cut out that part but nothing else, so maybe that's just the way modern planes are today. "Ready for landing check list, sir." "Okay. Wheels down?" "Check." "That's good enough for me! Let's land this pigboat!" Don,
If I might...: B777 check lists: http://www.itsyourplane.com/generator.asp?a=777-300 "That's good enough for me! Let's land this pigboat!" Nope...left that one out. Oh, that was last year's check list. Old hat!
Seriously, they must have cut it out, although it seems a tad strange, in that this wasn't some 'production', just a couple of guys doing a little video routine, so why not leave it in if 'realism' is the object? Just add it to our ever-growing list of aviation puzzles! Of course...you've the latest on file? It's actually quite specific. Even a C172 check list is more detailed than what has been suggested here.
We took a Cessna 172 up, up and away....did a few basic acrobatics... 172's not actually not able to carry 4 people, baggage and more that 1/3 fuel capacity (if the 4 people weigh more than 175#. Not even certified for "basic acrobatics"... What's been "suggested here" is that they edited the lists out of the vid. Puzzling, as I said above, but I guess they thought it would just be too boring for the average viewer.
There were two of us in the Cessna. Where did the "4" come from? Capability of carrying 4...wasn't saying you had 4 on-board at the time. One can get "over gross" very easily in an older 172.
The Citabria (CH7...Airbatic spelled backward) is quite a bird. Aerobatically certified and rated +5/-2 G's. Now...that's a ride!
#1.1.1.1.1.1
Garry
on
2013-09-04 02:53
(Reply)
You mean like from the 'Mayday' people? If I ever see one, I'll be sure to post it. While not as 'riveting' as most of their crashes, it's certainly got some unique angles to it. Not a lot of planes lose their entire tail and live to tell the story.
It is a credible theory, Doc. If it were found to be true I would imagine it would be declared to be a case of criminal negligence and a willful disregard fro the safety of the passengers.
I hadn't thought about it from a legal point of view, but you're probably right. In order to give themselves a bit of leeway and avoid such accidents, airliners might actually have an 'optimum' distance from the edge where they're supposed to touch down, like a quarter-mile or so. Ergo, specifically aiming for the edge would legally be 'negligence', but you can bet Asiana will never admit to it. It was all that darn autopilot's fault, betcha.
The VASIS/PAPI is generally set for a TD approximately 1500-2000' from the start of the runway's hard surface (usually a 3degree glide slope).
The GP on an ILS is usually set up TD @ 1200'. May vary, slightly, due to topography and/or obstructions. Does anyone recall which runway Asiana attempted to land on? I believe it was 28L.
http://en.wikipedia.org/wiki/File:SFO_map.png If you're practicing landings, you try to hit the same spot every time, not the beginning of the runway.
Thinking that autothrottle is handling the speed is enough to cause everything. You start to look low, and you raise the nose, which slows the aircraft and makes it sink steeper, making it worse. This feedback is unstable until you hit something. Normal pilots (without autothrottle) handle altitude with power and speed with attitude, just the reverse. Big problem if nobody's on the throttle. The Japanese landed a DC8 in the Bay back in the late 60s or early 70s, in sort of the same situation.
I don't know what the cause of that one was. "Approaching San Francisco, put on seat belt and rubbers" was the joke of the day. Having landed at SFO dozens of times, usually with a window seat, I have to admit it's pretty wild. It looks like you're inches above the water when suddenly, at the last possible sec, you see land and whoomp, you're down. I don't think there's another large airport in the US that's like that.
But there certainly is a small one down in San Carlos! rhharden,
As U know so well...water provides the worst horizon... TC Many, many moons ago I had a summer job for a company installing runway lights on Logan (Boston) Airport. Half the runways approach over Boston Harbor.
Since I was the only kid with a drivers license, I drove the truck out to the job site in the morning and back in the afternoon. We spend the day digging ditches (you know, the job no American will do), threading and laying pipe. We only had to cross one runway to get to the site and the only instruction I received was, stop and look before crossing. The truck had no two-way radio and we could barely see the control tower during the day. One morning, about 5:30am, very foggy, I was driving the crew out as usual. I stopped at the broad, white line and flashing red light at the edge of the runway. I couldn't see a G.D. thing. I rolled the window down and listened. Nothing. Well, I thought, those planes make a lot of noise coming in. (Most of it AFTER they pass, as I realized later) So I rolled forward. The truck had a boom, about ten feet high, normally down but yesterday we had used it to unload pipe at the end of the day and we didn't bother to lower it, I had forgotten about it by that morning. About midway across there was a brief warning of a high pitched scream and then the whole truck went up on one side and came back down...hard. She rocked back and forth several times with the boom slamming back and forth against its braces like the a church bell. Sound so loud we didn't hear it, we felt it, passed over. And then we were on the other side of the runway. I stopped and everybody got out, most stared at the fading lights of the jet that had just landed. Me and another guy checked out the boom. I figured if it looked like the jet and the boom had touched I'd have to fess up. It looked OK. We disappeared into the fog. Fun story. These days, of course, you'd probably have to get permission from the friggin' tower.
"Tower, this is 341 Ford Heavy requesting clearance to cross runway 35L." "341 Ford Heavy, proceed with crossing. Be advised there are other boom trucks in your vicinity." "Uh, roger, tower. Will we have to file a separate crossing plan for the return trip?" "That's affirmative, 341 Ford Heavy." A little different than just making a mad dash across the runway and hoping for the best. :) But you're right, though, you'd think an airliner would make bunches of noise ahead of it. They always do in the movies -- and those guys never lie! I guess I was below his line of sight. The (how did you know it was a Ford?) trucks headlights a puny pale competitor to the fixed runway lights.
Never heard anything more about it, the guys teased me about it the rest of the summer but nobody ratted me out. J t R,
That's why "Positive Control" was instituted at airports...! TC According to one report I saw, the Instructor Pilot on the Asiana flight noticed that they were low and told the Pilot Flying to "pull back on the yoke."
IMO, this is the way you might give instructions to a servomechanism, or maybe to a brand-new student pilot who had never been in an airplane before, but not to an actual human being who is an experienced pilot. The proper statement would have been "you're low, get back on the VASI," or something like that...which I think would have improved the odds that the PF would have noticed the low airspeed situation. According to one report I saw, the Instructor Pilot on the Asiana flight noticed that they were low and told the Pilot Flying to "pull back on the yoke."
Speculation...none the less...but: pull back on the yoke without sufficient airspeed (AS)...and you don't have to wonder where U're going to land cuz you'll never see it. It's right under U're A$$. As my instructor said to me MANY years ago (19-oh-68): "When you want to go up...pull back a little. When you want to go down...pull ALL the way back" !! Never forgot his WISDOM. TC Can anyone explain to me why the Asiana plane burst into flames so quickly? Do they know yet? How come they could not get the fire out before there was so much destruction? I have seen the video of it bumping in on arrival, but have not seen it burst into flames--doesn't look like that should have happened.
Well, from what I understand, it was just same ol' "leaking jet fuel" story, although it didn't happen "so quickly" or everyone wouldn't have gotten out in time. The only three deaths were outside the plane.
Between the thing not being engulfed in flames immediately, like usually happens, and it coming so close to cartwheeling, but not actually doing so, as I said in my original post, those might have been the luckiest passengers in the history of airline disasters. Based on the location of the smoke in the one photo I've seen prior to the fire (the one taken by the Samsung exec passenger), it looks like it started with the starboard engine. If you recall, it broke off and ended up snugged up against the forward fuselage on the right side. That is where the smoke appears to be coming from in the photo. Not too surprising that the engine may have caught fire in those conditions. Also explains why it took awhile for the fuselage to become fully involved.
I'm no pilot but I know that once an airplane slows, it has a number of taxiway options off the runway that traverse to various gates.
Could be they were assigned to a gate where taking an early exit saved time? That would encourage the earliest possible touchdown. Just a hypothesis to throw out there to test. And not a bad one. For all we know, the junior pilot was aiming for the 2,000-yard mark when suddenly one of the older pilots said, "Hey, it looks like there's a log jam on Exit 21 -- set 'er down a bit short so we can grab Exit 19."
And the rest is history? Excellent video of a professional crew (Lufthansa are one of the best in the world) flying the computer. Also shows the "cultural" aspect, of that cockpit, as well.
Very informative. That was LH's inaugural 380 flight into SFO May 8, 2011. |