LinkBack URL
About LinkBacksFacts are scares at the moment, apparently most people survived. It does look rather similar to a BA 777 that fell short at Heathrow five years ago.
If you've got anyone flying near SFO, expect them to be seriously disrupted.
Facts are scares at the moment, apparently most people survived. It does look rather similar to a BA 777 that fell short at Heathrow five years ago.
If you've got anyone flying near SFO, expect them to be seriously disrupted.
throw new ArgumentException (String, String, Exception)
A capture of the Tower traffic, at the end it confirms people were exiting the plane.
throw new ArgumentException (String, String, Exception)
Looks like it landed short. http://avherald.com/h?article=464ef64f&opt=0
Hope everyone got out alright.
Yeah on the displaced threshold.
People are assuming it must have been a power issue, that the engines didn't respond in the way wanted.
It is very similar to the 777 that fell short at LHR if that is true, however according to some gossip, it looks like they did not have the landing gear down, they should have had it down, even if they thought they were landing on water. The undercarage is the only bit of the plane designed to take the weight of the plane. However, it is possible that the pilots wanted the extra distance of glide, so didn't deploy it. It is also been assume that they where too far in the flair. Which caused the tail strike, this is odd, because if your short of space, you wouldn't try to flair, you'd go for a trolly landing.
Lots of speculation, very interesting case, good to see the cabin staff got people out quickly.
throw new ArgumentException (String, String, Exception)
Just reading the thread on PPRUNE about it, mods are active on the thread so its reasonably readable. They had details, including the radio recording, photos and video before most of the news agencies had woken up.
http://www.pprune.org/rumours-news/5...fransisco.html
interesting comments from some crew that have flown for them buried in there as well.
It is interesting, I've never seen so many people quick to blame the pilots. Normally its 'kind' to assume its a mechanical fault first!
But now everyone is saying that they were high of the glide slop, over corrected and a 777 isn't exactly a sprightly beast, so they couldn't get the power.
This is bad because even in a light aircraft you just go around, you don't risk a £35k plane's undercarriage. The radar telemetry (if correct) shows them far too high, they should have called it, gone around, but instead tried to force it in.
If so this is not only going to be bad for Korean airlines in general (their safety isn't great) but more about the fact pilots on these expensive commercial airliners never land them. For their concurrency, they have to fly 3 take offs and landings at day and night every 90 days, as sole manipulator of the controls. However the insurance companies don't like pilots, so they encourage firms to fly them manually for the minimum possible time. A result is that often they won't have flown them manually much.
In the case of SFO the ILS glide slope wasn't available due to maintenance, so they would have to fly it manually, but without having such a simple indication of their slope. If pilots are doing their concurrency only in the finest of conditions, with all the aids available, then it shouldn't be surprising when they fail to do something that's an edge case correctly.
Still, will be interesting, at least the Koreans aren't like the French when it comes to air investigations.
throw new ArgumentException (String, String, Exception)
They're saying they tried to abort the landing...
http://www.bbc.co.uk/news/world-us-canada-23222048The Boeing 777 that crash-landed at San Francisco airport was "significantly below" its target speed near the runway and the pilot tried to abort the landing, US investigators say.
The pilot was flying into San Francisco for the first time at the controls of a 777, Asiana Airlines says.
Yeah BBC isn't that good for this news.
The 'armchair analysists' actually appear to be one the ones who go on the news, rather than the ones in pprune or /r/flying
Pinched from:
http://www.reddit.com/r/flying/comme...anding_at_sfo/
Shows the plane before, then the Asiana plot. Notice they go above their glide slope. The go around should have been called then. They didn't they tried to fix the mistake, they cut power (it is assumed) then found themselves too far below the glide slope, slow and low, the engines in a trip seven don't respond instantly.
throw new ArgumentException (String, String, Exception)
No doubt the flight recorders will tell the true story. Until the records from the aircraft and airport flight control systems are analysed, it is pretty much all speculation.
(\__/)
(='.'=)
(")_(")
Been helped or just 'Like' a post? Use the Thanks button!
My broadband speed - 750 Meganibbles/minute
Yup things changed quickly from the first announcement to people's original speculations. However, as often is usual the quality of the internet armchair commenters has been much better than that of traditional format news.Originally Posted by peterb
The NTSB have had their press conference, and ultimately it is looking like poor pilotage, they confirmed that it was a visual approach (no ILS) and that the PAPIs were working before the crash took them out. Most shocking of all they confirmed that the go-around was announced 1.5 seconds from the ground, despite been in obviously a 4 red scenario. The go around should have been called when the plane was in the 3 red. ATP rules state something about 1,000ft AAL for this iirc. The question why he was above the glide slope, then below, less than 2 seconds before impact calling a go-around is one the press conference put right out there, in an unusual manner to drop the pilots in it so.
Lots of people don't think much of certain Asian pilots CRM as they have a culture where it is incredibly bad to question your seniors or elders. Suggesting he should go around is shameful, and is something many Asians (particularly higher class Koreans) simply would not do. This attitude is well document by pilots in the Korean war, and of course the pilot forums have jumped up with lots of people who were contracted by these airlines saying similar things.
Hopefully lessons in CRM will be learn, as will procedure for cabin staff escorting people to safety, un-trained/practiced people panic, it isn't at all shocking that a child would run in to the path of a firetruck.
It is a marked difference compared with the investigation attitude of AirFrance 447. If this is in response to the greater speculation and gossip on the internet (often as the one I've linked above someone who has more than a few licenses/endorsements) then great.
Also with Airliners constantly trying to save fuel and reduce insurance costs, maybe it will look more at making pilots practice G/S operations sans rnav!
throw new ArgumentException (String, String, Exception)
8 seconds from `go around` to full TOGA power - although you have meaningful lift at circa 4>5 seconds.
apparently the pilot flying was converting to the type , and whilst go around was called- the throttles *might* have been pushed home or not - its a tight call.
too low and too slow im afraid , controlled descent into the ground.
the chaps on pprune though have said its typical culture of that country - nothing at all from the company for hours after the event.
edit:
at 4 miles they realise they are still way above the slope - so cut the power back and *maybe* deploy spoilers (the power on the PW`s even on flight idle is ALOT) , hence the sharp drop in `speed`.
another observation on pprune is the lack of `hands on` visual flying done at far east airlines - a clear and perfect metar day like this and the aircraft was flown into the ground.
looking at the numbers - I wonder , did they actually stall?
edit2:
with flaps 30 and slats full down - the vref is usually about 136knots - they were way way below that.
Last edited by HalloweenJack; 08-07-2013 at 08:36 PM.
We don't know how heavy they were, 13 hours of fuel spent, the Vsr0 might be a lot less. Sadly I don't have the POH for the 777 in Asiana configuration. But looking at the video CNN have bought, it is flaring. Such a chord won't be helping things at all. I don't think they stalled, I think they had too lower power setting. They dropped a bit harsh from been high on the slope.
I think the main point is they over-corrected. The phrase is "pilot induced oscillation" I should know, I've done it enough in light aircraft.
Landing is always kind of hard without perfect preparation, I messed up a landing a little bit (nothing dangerous or expensive, just not perfect) by flaring too hard, too soon. This was because I hadn't kept the glide slope before, a bad set-up only leads to a bad landing and all that. It was my first time at that field! This was because I was low of the slope, over-corrected (power which meant speed) and thus went from too low and slow, to too high. This is with an engine that responds almost instantly. A heavy jet is much, much harder.
throw new ArgumentException (String, String, Exception)
would you like to work it out? we know the flight time , distance , SLF count - the METAR for the flight is available so given the public fuel data for the trip 7 - fuel weight can be calculated as well. they will have enough for a hold + divert + hold + reserve in the tank ; especially as its a 330min ETOPS flight
http://www.flightglobal.com/news/art...t-ntsb-388055/
TOGA applied at T -4 engines at positive power. idiots. they flew it into the ground.About three seconds prior to the impact, the aircraft reached its lowest speed during the descent of 103kt when its engines were at about 50% power and engine power was increasing. Investigations show that both engines were producing power during the impact, says Hersman.
The aircraft's autopilot was disengaged at about 488m (1,600ft) or 82sec prior to impact, the flight data recorder shows. At 1,400ft the aircraft had slowed to 170kt with 73secs to impact, by the time it reached 1,000ft it was travelling 149kt with 54sec to impact, at 500ft airspeed was 134kt with 34sec to impact, and at 200ft airspeed was 118kt with 16sec to impact.The throttles started moving forward at about 125ft when the aircraft was travelling at approximately 112kt, 8sec prior to the crash, the data shows.
Way to many unknowns :S The 777 and others like it actually weight themselves when on the ground to help the pilots calculate what their burn will be, the fuelling policy can vary madly too.
The METAR isn't any use for determining the true air speed either, just because the wind on the ground, with the detection equipment they have says x knots, does not mean at 400ft, the plane was experiencing it precisely, as the difference between slow flight and a stall is tiny, it's not going to be accurate enough. However, it doesn't matter if he stalled or not.
If you really want to know, what is needed is the accurate data from the flight recorder, the GPS might just about have the resolution to say definitively, but the pitot static definitely will give an indication, combined with the AI.
However, looking at the video, I don't see anything like a stall, I see a flare (which is a kind of stall in a way, just a forced, controlled one). The angle of attack is high, but he is still effectively on a glide slope. When people say a stall they normally mean that the wing isn't producing enough lift, what he had looked to be full flap, which changes the chord of the wing dramatically. I don't see why if he stalled is important. He messed up when he didn't follow procedures for a go around when at 1000AAL he was out of slope and speed. The fact he tried to correct, over corrected to a low and slow format, is a consequence of this action (it is a legal requirement to not attempt a landing in the approach he was in, if the flightaware data is right).
The fact he didn't follow that procedure, and no one else in the cockpit (including the training captain and the other PNF) were not saying "go around" is worrying.
throw new ArgumentException (String, String, Exception)
I am not a 777 rated pilot, but I thought that TOGA couldn't be applied when below 400ft AGL. The link just says they throttled up about 8 seconds prior to impact. I'm guessing that they did that very gently, as even in a dirty configuration (gear down, full flaps) If they had slammed the throttle to full they would have had a tiny bit more lift. As their speed was so slow, they had the obstacle of a sea wall, power in to land would have been the right call, as hitting the sea wall at any lower high could have been far, far worse. The fact that so few were injured by the tail striking it demonstrates how small the difference would have had to be. On second sooner or more full power, and it would possibly have been just a very hard landing.
pprune had guys saying it takes 7-12 seconds to throttle the engines to full, however, given that he had probably used his flaps and maybe his breaks to slow for the glide slope, (I think you can deploy them below 200kts IAS) he probably wouldn't have been able to go around no matter what at that point, because cleaning the craft would have been impossible in the time.
When looking at the video don't forget that he got his ground effect boost, this is even more noticeable during a slow approach.
throw new ArgumentException (String, String, Exception)
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote
