Air Asia disaster
Given the catastrophic crash, one must assume weather played a factor in the disaster; will the ATC's head be on the chopping block?
Why would permission ever be denied such a request, anyway?
Quote: MrVI wonder why the air traffic controller denied permission to ascend higher to avoid clouds?
Given the catastrophic crash, one must assume weather played a factor in the disaster; will the ATC's head be on the chopping block?
Why would permission ever be denied such a request, anyway?
I read that there were multiple planes in the area at higher altitudes so they couldn't do it right away because they needed to space the other planes out first.
Quote: MrVI wonder why the air traffic controller denied permission to ascend higher to avoid clouds?
Given the catastrophic crash, one must assume weather played a factor in the disaster; will the ATC's head be on the chopping block?
Why would permission ever be denied such a request, anyway?
Maybe it was one of the controllers that Regan fired.
Quote: 1BBMaybe it was one of the controllers that Regan fired.
Feel free to join us in DT for a more serious discussion concerning accelerated stalls at high altitude induced by unreliable pitot tubes or excessive wind variation due to Cb induced changes in air speed. Pilots think they are in an overspeed situation when in reality they are flying to slowly to stay airborne and are falling vertically. Even that radar screen grab shows the plane too slow.
Quote: FleaStiffFeel free to join us in DT for a more serious discussion concerning accelerated stalls at high altitude induced by unreliable pitot tubes or excessive wind variation due to Cb induced changes in air speed. Pilots think they are in an overspeed situation when in reality they are flying to slowly to stay airborne and are falling vertically. Even that radar screen grab shows the plane too slow.
Okay, let me go to the suspension list to get the link to DT. Actually I've read the thread and it's really good. Not to single anyone out or to slight anyone, but when I see Paco's name on something I know it's going to be good.
Quote: MrVI wonder why the air traffic controller denied permission to ascend higher to avoid clouds?
Given the catastrophic crash, one must assume weather played a factor in the disaster; will the ATC's head be on the chopping block?
Why would permission ever be denied such a request, anyway?
I'll try not to get too far in the weeds (don't mean to be patronizing, just that I could write a book on this), but in general;
1. Radar over oceans is unreliable because of gaps. Non-radar procedures are used. Primarily this is altitude; jets are assigned them 1000-2000 feet apart.
1a. Time-point reporting is used to determine when aircraft have passed; radar info backs that info up, but nothing is assumed - it depends on reports.
1b. If a routine request is made, it is denied if there is projected traffic in the way. They can't just tell by looking at the screen; they have to run out the math on where everyone is, and be very conservative about it.
1c. If an aircraft is in distress and tells the controllers, all that goes out the window, and the controller will immediately approve the climb and any other action the pilot tells them about, and move everybody else out of their way if at all possible, certainly passing traffic information at a minimum. The other pilots are also hearing this and immediately do whatever they have to, usually based on controller instructions, but also based on cockpit warning systems known as TCAS or ADS-B (different airborne traffic information systems) if the pilot in distress sets off their cockpit alarm with his maneuvers, or if they can see him on their system and know it's coming.
2. Thunderstorms go up 40-55 thousand feet, with further turbulence above that, around 5000 feet.
2a. The service ceiling of commercial airliners like the A320 stops around 39 thousand, or lower. They can't top the thunderstorms.
2b. The only workable solution for most thunderstorms is to deviate laterally (around); pilots generally have to ask, though controllers often initiate deviations based on scope presentation.
2c. Thunderstorms contain severe up and downdrafts, based on temperature of different air masses rising and falling, and precipitation, well-fueled by being over water. Hot wet air rises, water condenses and solidifies as it cools, then falls as rain or hail.
2d. If an aircraft gets caught in a severe updraft, or even cooling wet air, the ice will stick to the airframe and instruments. It can be gradual and pilots may not realize their instruments are getting iced up - perception especially deceptive in a summer climate, where it might be 60 degrees or more warmer on the ground.
3. The air masses also cause turbulence. Air carriers tend to slow down in turbulent areas, because it lessens the severity felt in the cabin. The instruments detecting airspeed, as they ice up and the opening becomes narrower, start giving erroneous readings, indicating you're going faster than you are.
3a. The slower you go, the more likely the aircraft is to stop flying. The more ice build-up, the faster your airspeed has to be to keep the air moving over and under the wings (it's the displacement of air over the top of the wings, and the vacuum it creates, that allows you to fly - it also matters that ice adds both weight and changes the shape and smoothness of the wing). The higher your nose is pitched, like in a climb, the faster you have to be going to stay flying. The higher you are, the thinner the air is (so there are less molecules to displace) so the faster you have to go.
So, in this accident (I'm going to say this without all the info, and we'll see what they say in the investigation), the pilots did not declare an emergency or ask for priority, they waited too long to take action by deviating and got into the heart of the thunderstorm, the aircraft couldn't climb above the storm (it was reported tops at 55 thousand feet). It's likely the updrafts carried them higher anyway (they're indicating a climb), they had inaccurate info on their airspeed and/or altitude from iced instruments, and they didn't know how slow they were going, and they were in severe or extreme turbulence.
As a result of all these factors each taking their toll on airspeed, the wings stopped providing lift and they fell out of the sky either tail first, or one wing flew and the other didn't and they went into a spin and couldn't get the airframe to fly again or ran out of room. (The recovery would take full power, nose pointed down, correct any spin while in free-fall if this is what happened; they may have simply run out of altitude while trying to fly.) The airframe could have torn off a wing or two on the way down if their recovery effort overstressed the airframe, but more likely the aircraft broke on impact, either just ahead of or behind the wings.
This is pure speculation, and only my guess on what's most likely happened. The investigation will likely take a year or more, but the preliminary should come out within a week or so.
Quote: GWAEAll I know is that I am never flying near Asia
At least not on a Malaysian carrier.
Crossing traffic was UAE409, crossing left to right of QZ at 36000 feet. They were projected to come too close, with QZ slightly through the intersection first, but slowing and making even more of a direct conflict.
QZ started at 32000 and asked for 38000, was given 34000 because of UAE. 2000 is common at higher altitudes because the thin air can introduce a greater error in altimeter readings than can be tolerated at lower altitudes, where 1000 is common.
QZ, however, at the time of the screen grab, had busted altitude and was through 36300, still indicating a climb, still pointed at UAE. Speed was 353 knots, near-stall speed at that altitude for an A320. Had they remained airborne, it's likely the pilot would have been in serious violation, maybe even lost his license, for flying through the other aircraft.
Couldn't tell the scale of the scope, but looked like they would have passed in maybe 6-7 minutes, maybe less.
In that conflict configuration, had QZ declared an emergency or asked for priority, the controller would have turned UAE immediately hard right in order to pass behind QZ. Without the priority request, the controller continued to use altitude separation while allowing the QZ to turn however he liked to avoid the weather. This is both standard and expected by all parties, as it is the least disruptive to the flights and does not unduly inconvenience a second party to accommodate the first.
EDIT: Ok, here's the screen shot.
Looking at it again, the 2 aircraft have just passed, and are now diverging, with the UAE off to the right in about QZ's 1 oclock position. Normal airspeeds, they would have crossed directly and very close, but QZ slowed in the climb to where UAE managed to cross first. Had QZ climbed with a normal airspeed, it's very possible they would have hit, as unlikely as that usually is. This picture scares the hell out of me, and honestly, in the US, this controller would be in serious trouble for not noticing and calling out the pilot for busting altitude or taking action with someone so close, well before they got to this point. Not sure how things got here without someone saying something on the radio. Again in the US, pilot would have to have declared an emergency before doing this (or immediately after) to not lose his license and job.
I wonder if the pilot ever acknowledged the control instructions he was given (turn ok alt capped at 34K); he may not even have heard them, looking at what he did.
There's also an aircraft just on the top edge of the picture at 35K. He could be the reason QZ was stopped at 34.
Quote: DaddydocAt least not on a Malaysian carrier.
In that part of the world thunderstorms go to much greater heights than our expert, BBB, quoted and they pack a real punch. The worst are the morning thunderstorms.
Was it a Go-No Go decision? I don't know. I do know that on a low cost carrier a pilot's No Go decision is rare.
Was it WX radar?
Certainly the airplane was already slow and if freezing rain on his pitot tube heater gave him an erroneous reading of overspeed he should have known that turbulence did not in fact give him a wallop that increased his speed but that instead indicated airspeed was unreliable and he was in fact in a stall where the wing is not generating lift because the nose is so high. Of course sudden ice accumulation would help to lower the lift (weight and irregular surface) but the main task would be to recognize it was a high speed stall and lower the nose to regain lift situation rather than some sudden overspeed situation where he should raise the nose to slow the plane down before the control surfaces take too much strain.
There are problems in that part of the world with inadequate training.
Quote: FleaStiffIn that part of the world thunderstorms go to much greater heights than our expert, BBB, quoted and they pack a real punch. The worst are the morning thunderstorms.
Was it a Go-No Go decision? I don't know. I do know that on a low cost carrier a pilot's No Go decision is rare.
Was it WX radar?
Certainly the airplane was already slow and if freezing rain on his pitot tube heater gave him an erroneous reading of overspeed he should have known that turbulence did not in fact give him a wallop that increased his speed but that instead indicated airspeed was unreliable and he was in fact in a stall where the wing is not generating lift because the nose is so high. Of course sudden ice accumulation would help to lower the lift (weight and irregular surface) but the main task would be to recognize it was a high speed stall and lower the nose to regain lift situation rather than some sudden overspeed situation where he should raise the nose to slow the plane down before the control surfaces take too much strain.
There are problems in that part of the world with inadequate training.
I think training may well be an issue, but it doesn't make sense with his experience level and the amount of monsoon weather he'd had to navigate flying in that part of the world for decades. He should have known better, and maybe he did.
It may turn out that his altitude request was a CYA, and that the airplane went up uncommanded in an updraft/turbulence and he was trying to save his job. As I said in my last (edited) post, he would have been in serious trouble, at least here, for what he did. The CVR and FDR will be very useful in figuring out that timing and what they said to each other before they called for the altitude.
Quote: beachbumbabsI think training may well be an issue.
Aren't most airline accidents pilot error?
And that part of the world is known for
crappy pilots? You can move up to pilot
from co-pilot by paying somebody off.
Gee, I think I'm never flying on a plane
that originates there.
My son just became an airline pilot after
17 years as an AF pilot. He says there
is no way the Asian pilots get the constant
training upgrades they get in the West.
You get what you pay for, buyer beware.
Quote: beachbumbabsI'll try not to get too far in the weeds (don't mean to be patronizing, just that I could write a book on this), but in general;
1. Radar over oceans is unreliable because of gaps. Non-radar procedures are used. Primarily this is altitude; jets are assigned them 1000-2000 feet apart.
1a. Time-point reporting is used to determine when aircraft have passed; radar info backs that info up, but nothing is assumed - it depends on reports.
1b. If a routine request is made, it is denied if there is projected traffic in the way. They can't just tell by looking at the screen; they have to run out the math on where everyone is, and be very conservative about it.
1c. If an aircraft is in distress and tells the controllers, all that goes out the window, and the controller will immediately approve the climb and any other action the pilot tells them about, and move everybody else out of their way if at all possible, certainly passing traffic information at a minimum. The other pilots are also hearing this and immediately do whatever they have to, usually based on controller instructions, but also based on cockpit warning systems known as TCAS or ADS-B (different airborne traffic information systems) if the pilot in distress sets off their cockpit alarm with his maneuvers, or if they can see him on their system and know it's coming.
2. Thunderstorms go up 40-55 thousand feet, with further turbulence above that, around 5000 feet.
2a. The service ceiling of commercial airliners like the A320 stops around 39 thousand, or lower. They can't top the thunderstorms.
2b. The only workable solution for most thunderstorms is to deviate laterally (around); pilots generally have to ask, though controllers often initiate deviations based on scope presentation.
2c. Thunderstorms contain severe up and downdrafts, based on temperature of different air masses rising and falling, and precipitation, well-fueled by being over water. Hot wet air rises, water condenses and solidifies as it cools, then falls as rain or hail.
2d. If an aircraft gets caught in a severe updraft, or even cooling wet air, the ice will stick to the airframe and instruments. It can be gradual and pilots may not realize their instruments are getting iced up - perception especially deceptive in a summer climate, where it might be 60 degrees or more warmer on the ground.
3. The air masses also cause turbulence. Air carriers tend to slow down in turbulent areas, because it lessens the severity felt in the cabin. The instruments detecting airspeed, as they ice up and the opening becomes narrower, start giving erroneous readings, indicating you're going faster than you are.
3a. The slower you go, the more likely the aircraft is to stop flying. The more ice build-up, the faster your airspeed has to be to keep the air moving over and under the wings (it's the displacement of air over the top of the wings, and the vacuum it creates, that allows you to fly - it also matters that ice adds both weight and changes the shape and smoothness of the wing). The higher your nose is pitched, like in a climb, the faster you have to be going to stay flying. The higher you are, the thinner the air is (so there are less molecules to displace) so the faster you have to go.
So, in this accident (I'm going to say this without all the info, and we'll see what they say in the investigation), the pilots did not declare an emergency or ask for priority, they waited too long to take action by deviating and got into the heart of the thunderstorm, the aircraft couldn't climb above the storm (it was reported tops at 55 thousand feet). It's likely the updrafts carried them higher anyway (they're indicating a climb), they had inaccurate info on their airspeed and/or altitude from iced instruments, and they didn't know how slow they were going, and they were in severe or extreme turbulence.
As a result of all these factors each taking their toll on airspeed, the wings stopped providing lift and they fell out of the sky either tail first, or one wing flew and the other didn't and they went into a spin and couldn't get the airframe to fly again or ran out of room. (The recovery would take full power, nose pointed down, correct any spin while in free-fall if this is what happened; they may have simply run out of altitude while trying to fly.) The airframe could have torn off a wing or two on the way down if their recovery effort overstressed the airframe, but more likely the aircraft broke on impact, either just ahead of or behind the wings.
This is pure speculation, and only my guess on what's most likely happened. The investigation will likely take a year or more, but the preliminary should come out within a week or so.
Babs...the goddam plane went down. Do you think we need your big explanation?
Fascinating stuff. Also fun to see members' areas of expertise.
Quote: mickeycrimmBabs...the goddam plane went down. Do you think we need your big explanation?
mick,
The question was asked or I wouldn't have gone there. It's usually foolish to speculate absent the facts, which is why I said "in general" for most of it.
Don't like the way the news networks spent 2 days implying the controller screwed up just because they had nothing else of substance to say while they were looking for the plane. Their accusations are probably why the controller snuck out the radar grab prior to the investigation.
So when V asked and nobody else said anything, I didn't want to just say, "no" and come off as blindly defensive, which led to my long post. Which could have run 500 pages, easy, if I said everything I have to say about what I touched on.
It's also left-over sparrow disease. You never really leave a job like that; you just die a little every time one gets lost. And you want to know why so it never happens again.
EB,
This is a pilot to whom this should have been a routine operation. There's a disconnect, so either catastrophic failure or carelessness/negligence are going to play a bigger part than lack of training, though the training (more likely, non-retention of training info) will probably be a factor as well. My opinion.
New info:
Two of the initial bodies were naked. That strongly implies at least a partial break-up before impact, because water doesn't usually rip off clothes, but free-falling often does. So either a wing was ripped off (most likely) and/or explosive decompression (hole in the side) is part of this.
Quote: beachbumbabsmick,
Two of the initial bodies were naked. That strongly implies at least a partial break-up before impact, because water doesn't usually rip off clothes, but free-falling often does. So either a wing was ripped off (most likely) and/or explosive decompression (hole in the side) is part of this.
Bbb your post was to long for me to comprehend. Are you saying that 2 planes could have collided if they kept their current path? What are the odds that 2 planes intersect each other in the middle of the ocean. Hundreds of millions of sky miles and 2 planes end up at the same place. That is just crazy unluckyness.
Also, I can not think of a worse way to die than to just be sitting in a plane and then all of a sudden you are sucked out because the wing was ripped off. I really hope they died while falling and not from hittjng the water. The terror for 30 seconds while free falling is just terrible. When it is my time I hope I die from an aneurysm while sleeping.
Yes...Quote: EvenBobAren't most airline accidents pilot error?
Pilot error induced by scheduling fatigue, sleep deprivation, design elements, poor charts, poorly named waypoints, sticky keyboards.
>You can move up to pilot from co-pilot by paying somebody off.
Pay To Fly and other arrangements are an industry pressure.
India has pilots with thousands of hours on their logbooks who have never been inside the cockpit of an airplane.
>Gee, I think I'm never flying on a plane that originates there.
How about Air France, it has the LOWEST ratio of instructors.
>You get what you pay for, buyer beware.
Precisely, but pilots are now "burger flippers''. Thats the money they make and thats the clout they have.
You think a pilot in Air Asia refuses to take off due to weather? Or being overweight?
You think a controller or pilot would really be in any trouble at all out there? The cultural attitude is close your eyes and hope that if it hits the fan it does it on someone else's watch.
Air Asia pilots rarely Go Around for another approach, that is admitting failure. So they land long and at high speed and go hydroplaning off the end of the runway.
Just look at the sequence of declarations by the Controller here.... it was 98 minutes before the controller sounded an alarm that any Western controller would have sounded within ten minutes.
Yes, you get what you pay for, but passengers want cheap flights and are willing to pay for unsafe ones provided they get a bag of peanuts with it.
This plane was inspected November 14 to 16.
Bodies: looting by local fishermen?
And yet the pilots did not issue a distress signal. The plane disappeared after it failed to get permission to fly higher to avoid bad weather because of heavy air traffic.
"The fact that the debris appears fairly contained suggests the aircraft broke up when it hit the water, rather than in the air," said Neil Hansford, a former pilot and chairman of consultancy firm Strategic Aviation Solutions.
The plane was travelling at 32,000 feet (9,753 metres) and had asked to fly at 38,000 feet. When air traffic controllers granted permission for a rise to 34,000 feet a few minutes later, they received no response.
Online discussion among pilots has centered on unconfirmed secondary radar data from Malaysia that suggested the aircraft was climbing at a speed of 353 knots, about 100 knots too slow, and that it might have stalled.
Investigators are focusing initially on whether the crew took too long to request permission to climb, or could have ascended on their own initiative earlier, said a source close to the inquiry, adding that poor weather could have played a part as well.
A Qantas pilot with 25 years of experience flying in the region said the discovery of the debris field relatively close to the last known radar plot of the plane pointed to an aerodynamic stall. One possibility is that the plane's instruments iced up, giving the pilots inaccurate readings.
The Indonesian captain, a former air force fighter pilot, had 6,100 flying hours under his belt and the plane last underwent maintenance in mid-November, said the airline, which is 49 percent owned by Malaysia-based budget carrier AirAsia.
Quote: beachbumbabsDon't like the way the news networks spent 2 days implying the controller screwed up just because they had nothing else of substance to say while they were looking for the plane. Their accusations are probably why the controller snuck out the radar grab prior to the investigation.
The way networks cover ANYTHING stinks. They start with an endless parade of "experts" who know nothing about what actually happened and create for us a storyline that may not even be close to the actual truth. They may move around to the truth as it comes about but by then most everyone has stopped listening and never really hears why it happened because they are on to the next crisis.
We'd be better off with a report of the situation, the actions being taken, and when the next major update will be...and then the information about the "why" following when there is at least enough known to present two or three possibilities.
This is why "perp walks" work so well; ruining people before they are even tried. It is why "hands up, don't shoot" is believed by so many in spite of the evidence presented. I'm waiting for a lot of it in the 2016 election cycle...stuff on candidates that is not true and proven such, but believed by many because they heard it on the news.
Thanks, BBB, for discussing the issue, which is a lot different than inflating the airwaves with hot air...everyone here knows it is a discussion, not a presentation of facts at this point.
While no expert, I've always been fascinated with aviation in general, a couple of things I've been told by people in the business really seem to apply to this tragedy.
1. To bring down a commercial airliner (terrorism aside), usually requires a couple of things. Some combination of pilot error, systems failure, and environmental issues. Sounds like all three were present in this case. Not to mention some questionable ground control issues. That's just some bad confluence of events.
2. It's the combination of these "minor" factors that lead to the crash. Any of them would be survivable on their own; but the combination of say, ice on the instruments, slow pilot reaction, and a monster thunderstorm, plus maybe some as yet unknown mechanical failure... can be, and in this case was, deadly.
3. The media tends to report these things in a really over simplified way. Without emphasizing that any of these issues, in and of themselves, would be unlikely to cause a loss of aircraft. They always want a simple answer "it's the pilots fault"...the "wing fell off" whatever. The real answers are always more complicated than that.
Quote: JohnnyQBBB: Fascinating stuff. Also fun to see members' areas of expertise.
+1. Thanks for sharing your knowledge, babs. There seem to be multiple members here with ATC knowledge/experience. Certainly more than I know in real life, which is 0.
The airlines would love to put two Dobermans in the cockpit because it would be so much cheaper, but in the unusual event of something going wrong, the airline would never be able to blame the poor mutts, so they use humans instead.
Pilots just sit there and push buttons and don't really fly the airplane anymore, particularly in a fly by wire plane wherein the computer is flying and will countermand any unsafe pilot input.
Its just that when things go really really wrong, the computer shuts its self off and says Good Like Guys. Whereupon these button pushers suddenly have to do is grab the controls and start flying the airplane and they don't know HOW to do it.
IF freezing rain and monstrous winds were encountered, the computers and the pilots have a very short time to sort things out. Is it overspeed and they must slow the plane down by raising the nose or is it pitot icing and they must lower the nose to keep from stalling the plane. The crew of AF447 made the wrong decision and they hit the ocean in four minutes, having started ten thousand feet higher that Air Asia plane did.
Bottom line- buy Boeing - fly Boeing
The Airbus 320 takes the flight crew out of the loop, when something goes wrong, the crew is put back in the loop too late with too little information.
Quote: Sabretom2There sure seems to be plenty of experts around this here Internet. Any real expert understands the folly of speculation in this type of case. Makes me wonder why one might desire to impress a bunch of faceless key tappers.
I asked, she answered.
Thanks, BBB.
Quote: Joeman+1. Thanks for sharing your knowledge, babs. There seem to be multiple members here with ATC knowledge/experience. Certainly more than I know in real life, which is 0.
+1
Thank you and please keep discussing.
Yes, BBB.Quote: Sabretom2There sure seems to be plenty of experts around this here Internet.
>Any real expert understands the folly of speculation in this type of case. The final report means more but its three years away.
In the interim, three cheers for BBB.
> Makes me wonder why one might desire to impress a bunch of faceless key tappers.
You'll have to ask the cable news types about that.
>Bottom line- buy Boeing - fly Boeing
I'd generally prefer that.
>Airbus takes the crew out of the loop, when something goes wrong, the crew is put back in too late with too little information.
Yes, that is fly by wire... the engineers deem the computer more reliable than the humans.
Quote: vendman11. To bring down a commercial airliner (terrorism aside), usually requires a couple of things. Some combination of pilot error, systems failure, and environmental issues. Sounds like all three were present in this case. Not to mention some questionable ground control issues. That's just some bad confluence of events.
.
One of my favorite TV shows is the Smithsonian channel Air Disasters.
They spend an hour looking at one incident and all the research afterwards regarding the crash investigation.
A Korean airliner veered into Soviet territory and was shot down many years ago.. The show examined that incident and even had an interview with the pilot that shot down the airliner.
Really fascinating how a combination of different scenarios bring down a plane.
What is sad is that many of these disasters were preventable.
It can take a year or years to determine what happened.
When a finding is announced, its not big news a lot of times because the incident happened so long ago.
This show is great, puts it all together in an hour.
Quote: FleaStiffYes, BBB.
>Any real expert understands the folly of speculation in this type of case. The final report means more but its three years away.
In the interim, three cheers for BBB.
> Makes me wonder why one might desire to impress a bunch of faceless key tappers.
You'll have to ask the cable news types about that.
>Bottom line- buy Boeing - fly Boeing
I'd generally prefer that.
>Airbus takes the crew out of the loop, when something goes wrong, the crew is put back in too late with too little information.
Yes, that is fly by wire... the engineers deem the computer more reliable than the humans.
Boeing is also using fly by wire. The difference is the Boeing controls operate much more like mechanical controls than the Airbus ones, although Boeing does now have flight envelope protection like the Airbus. This wikipedia article has an overview. http://en.wikipedia.org/wiki/Flight_control_modes
I prefer the way Boeing does it.
Quote: FleaStiffQuote:Yes, you get what you pay for, but passengers want cheap flights and are willing to pay for unsafe ones provided they get a bag of peanuts with it.
This plane was inspected November 14 to 16.
Not sure if this statement of mine is even accurate?
I read a few years back that most/all large aircraft maintenance would no longer be done in the US, most, if not all commercial airliner maintenance for the US anyway was moved to Mexico?
As the story progressed it was reported that one applicant for a maintenance position turned out to be a 16 year old from the Caribbean who claimed on his resume to have five years experience?
Quote: GWAEBbb your post was to long for me to comprehend. Are you saying that 2 planes could have collided if they kept their current path? What are the odds that 2 planes intersect each other in the middle of the ocean. Hundreds of millions of sky miles and 2 planes end up at the same place. That is just crazy unluckyness.
Also, I can not think of a worse way to die than to just be sitting in a plane and then all of a sudden you are sucked out because the wing was ripped off. I really hope they died while falling and not from hittjng the water. The terror for 30 seconds while free falling is just terrible. When it is my time I hope I die from an aneurysm while sleeping.
GWAE,
Sorry about that. Looking only at the radar grab, which is a moment in time on an ever-changing thing, the following happened.
IN the 10 minutes before the screen shot.
UAE was NNW bound level at 36000 feet. he was fast.
QZ8501 was also NNW bound, roughly parallel off his right wing, at 32000. Probably same/similar speed. Given the screen shot and speeds, he was physically ahead of UAE before he started maneuvering.
QZ8501 asked for and got approval for a left turn, which turned him towards UAE. He also asked to climb, which was approved to 34000. He started climbing, which would have slowed him, don't know how much, but it affected his speed to some extent.
QZ8501 didn't stop at 34000. He kept climbing right THROUGH the other guy, pointed at him, but slowing enough that the other guy passed ahead of him.
QZ8501 also climbed through an aircraft at the top of the picture at 35000 feet, probably opposite direction to him, but can't tell from the shot. It's likely that was the aircraft for which they stopped him at 34000.
At the time of the screen shot, QZ8501 was in the same altitude block as UAE. Had he kept a normal climb rate/speed and done that turn, it's possible they would have hit. There are many reasons, including traffic detectors on the other aircraft, it shouldn't happen. But he definitely made it possible.
If the pilot had declared an emergency or advised he was in an uncontrolled climb for updraft, the controller would have moved the other 2 aircraft immediately. He didn't. So they didn't.
I mean, speed is everything. All the million parts and processes, all the complicated physics, everything a plane is depends on speed. Yet it seems like such an afterthought.
If memory serves, air speed is determined by a gauge that measures the force of air entering a device. The harder the air enters, the faster it reads you're going. But think about that. What if you have a simple electrical malfunction? What if the device is bumped and shifted off true? What if a bit of ice or a bit of water or a bit of eagle's feathers obstructs the opening? Then what?
It seems a rudimentary device should be affixed somewhere the pilots can always see it. Something like a spring loaded flap. Springs strong enough to withstand air pressure up to a point, but once you cross a threshold (say 250kts), the pressure is enough to close it. That way, any time you drop below it, you can see, with your own eyes right in front of you, whoopsie, we're getting slow.
I'm sure there's a problem with my flap idea, but there should be something along those lines. Speed is everything. It is unacceptable to not know it during every second of operation.
The first time I did a power on stall in a Cessna was actually pretty scary because I went into an immediate hard spin. I couldn't imagine how scary it would have been if I was not expecting a stall.
Quote: DRichBabs, historically how common is it for a commercial aircraft to have a stall situation at altitude? Are they usually fatal or are most pilots/equipment able to rectify the situation?
The first time I did a power on stall in a Cessna was actually pretty scary because I went into an immediate hard spin. I couldn't imagine how scary it would have been if I was not expecting a stall.
DRich, it's very uncommon. In jets, maybe 1-5 per year, keeping in mind there are millions of jet flights per year. It's almost always due to some other factor, usually icing. Icing is usually very hard to detect in the investigation; it has to be implied, because the evidence melts, and most of it is generally knocked off on impact anyway.
However, the majority of fatal crashes of commercial in the last 20 years "probably" had icing as a factor (not counting 9-11). The Chataqua in Buffalo, Air France off Brazil, probably this one, the ATR-42 and ATR-72 smaller airplane incidents (can't think of the places, but there were at least 2 others in that design), several others.
The industry generally takes prophylactic measures about icing, rather than being able to deal with it in-flight, though it's routine to get some accumulation and melt/knock it off through heating the instruments and physically knocking it off the front of the wings (they call them "boots" - little mechanisms under rubber on the leading edge of wings; they move when you turn them on and break up the rigid crystal structure of the ice forming). Mostly pilots and controllers rely on icing reports and avoid altitudes and/or areas of known icing.
This is an area of fast-evolving technology and algorithms in predicting where it is, because currently you can't tell for sure before you're in it, and if it builds up too fast and/or too thick, you're in trouble.
If you get too much ice, you generally go lower, both to get out of it, and to melt off what you've accumulated at the higher temperatures generally beneath you. That isn't always possible. There may not be a safe altitude far enough below you to help (like over the Rockies), or there may be a temperature inversion (trapped layer of cooler air down below dense moist air with icing).
Air temperature cools at an aviation standard of 3 degrees F/2 degrees C per thousand feet of altitude. Jets up at 30000 are routinely in -25F or so air, well above any air that can hold water. However, thunderstorms change that dynamic, because they throw hot, moist air upwards at great speed with the flow of the air mass, allowing supercooled water (air below freezing temp but water still liquid) to be present, which solidifies on any available mass, usually an airframe. This is part of the reason jets avoid thunderstorm clouds, but can safely fly through other types of clouds. (The larger reason is that the violent vertical airmass movement creates dangerous turbulence). This is also how hail is created (with supercooled droplets sticking into ice, gaining more as they fall, falling too fast to melt before they get to the ground).
Perhaps more detail than you wanted, and strayed a bit into related info.
Quote: mickeycrimmBabs...the goddam plane went down. Do you think we need your big explanation?
I found it interesting......if you didn't, feel free to skip the post, but your comment is out of line Mickey.
Stall situations are generally avoided short of a full stall. When aircraft were manual/hydraulic, there were many indications the aircraft was about to stall; drop in airspeed, wallowing in the air, slow response to yoke movement. The yoke would physically shudder in your hands. Most importantly, there is/was a stall warning horn that goes off when the instruments detect the loss of airspeed. More apparent in prop airplanes than jets, but still present.
When they started building fly-by-wire, those physical clues went away, and you were completely dependent on the aircraft telling you it was stalling; you couldn't feel it. They had to build those back in (especially the stick shaker) so that pilots could tell they were stalling.
Stall recovery is routinely part of initial and annual refresher training for all pilots. Jet pilots do their refreshers in simulators, often being put into fatal configurations learned through investigation and being taught how to get out of it. However, really being faced with it (and the simulators are very good, but...) can be a different thing.
There was a Delta offshore California in the 80's, for example, that accidently turned off both engines at altitude. The aircraft stalled out and fell to within a couple thousand feet of the ocean before they got the engines started again and built enough speed to fly them.
Sully landed an A320 in the Hudson in part by holding the aircraft in a climb attitude just approaching stall while dropping without power when geese took out both engines. That should have been fatal but he kept it together and landed just right. I'm not sure reports at the time fully appreciated the miracle that was, no matter his skill level. It also proved how hardy the A320 engineering was, that the aircraft didn't break open when the tail hit first, but that was also Sully holding it in the climb/stall attitude, slowing it enough to slam down without cracking.
So, anyway, the majority of full stall-recovery is probably under-reported, nearly all of it would be caused by either catastrophic loss of engines (very rare), thrown by updrafts/downdrafts (likely most occurring , and most easily recovered from), and gradual icing accumulation (most likely for fatals).
Quote: vendman1BBB, thanks for the info, nice to hear from someone who has knowledge in the field we are discussing.
While no expert, I've always been fascinated with aviation in general, a couple of things I've been told by people in the business really seem to apply to this tragedy.
1. To bring down a commercial airliner (terrorism aside), usually requires a couple of things. Some combination of pilot error, systems failure, and environmental issues. Sounds like all three were present in this case. Not to mention some questionable ground control issues. That's just some bad confluence of events.
2. It's the combination of these "minor" factors that lead to the crash. Any of them would be survivable on their own; but the combination of say, ice on the instruments, slow pilot reaction, and a monster thunderstorm, plus maybe some as yet unknown mechanical failure... can be, and in this case was, deadly.
3. The media tends to report these things in a really over simplified way. Without emphasizing that any of these issues, in and of themselves, would be unlikely to cause a loss of aircraft. They always want a simple answer "it's the pilots fault"...the "wing fell off" whatever. The real answers are always more complicated than that.
vendman,
Good observations and very correct IMO. Moving from a single catastrophic event to a chain of minor effects leading to catastrophe has been a 60 year evolution in accident investigation. Starting with absolving all parties from liability in exchange for brutal truth in all parts and testimony, leading to identification of major flaws, leading to mandated changes in whatever identified causes, leading to increasing safety margins. As the major causes are identified and fixed/trained, less-catastrophic and more subtle factors come into play and are corrected in turn, increasing in minuteness and pertinence through knowledge. To where now, accidents are increasingly rare, it takes several things going wrong/reacted to wrongly to reach a fatal level.
They've fixed so many of the inherent design/procedural/system-wide flaws that, by percentage, human error is now the main issue in more than 90% of fatal accidents. Usually errors of judgment or lack of knowledge when faced by unusual circumstances. That's why they recreate the accidents in the simulators for other people's training, and force controllers and pilots to review fatal tapes and records; both to teach you how to see the little issues that can snowball and "break the chain", and to raise your awareness of what inattention/distraction/outside issues can lead to.
As to the media, totally agree.
Quote: beachbumbabs
Thanks for the explanation.
IMO, re: MC's comment and he can correct me if I'm wrong.
I took it as a Fremont Street Commando's inebriated method of giving a compliment. It probably doesn't appear that way to others that haven't traveled that path, but is how it looked to this old rock carver? just sayin
Even if I am incorrect, I know I am certainly impressed. I knew you was smart. :)
Quote: petroglyph
Thanks for the explanation.
IMO, re: MC's comment and he can correct me if I'm wrong.
I took it as a Fremont Street Commando's inebriated method of giving a compliment. It probably doesn't appear that way to others that haven't traveled that path, but is how it looked to this old rock carver? just sayin
Even if I am incorrect, I know I am certainly impressed. I knew you was smart. :)
I attributed it 100% to drink and took it as a backhanded compliment that he posted as he did - he meant it as a joke. He can also correct me if I'm wrong.
It may well go back to a Go-NoGo decision, which of course has economic implications because pilots on discount airlines often have no real clout. The controller and the radio communication will deal with the conflicting traffic, verbal precision issues.
But is still comes down to : pitot icing induces a sudden warning "overspeed". The crew believes it due to recent turbulence and raises the nose to slow the plane down when instead they should keep the controls where they are and simply cancel the overspeed warning realizing that its the airspeed system that is malfunctioning.
AF447 didn't know what to do. Air Asia should have.
Quote: DRichBabs, since there seem to be Pitot tubes icing up on many occasions, do the planes use GPS as a backup indicator for airspeed and altitude? I know my $99 Garmin shows both when driving.
That's a more complicated question than it might seem.
If you're going to put a system on an airplane, especially commercial, it involves a lot of regulation and training, probably a mandated change from regulators rather than voluntarily equipping the aircraft, as well as the cost of the equipment. Transitioning to GPS has not yet been mandated by ICAO (international regulators) due to the cost of doing that to operators both large and small, probably in the tens of millions of dollars for a company like AirAsia. They then more expense subscribing to a GPS service and continuing education/refreshers on its use. This accident (when considered along with AirFrance and the MH370 disappearance) may push the regulators into mandating it despite the cost.
Informally, nearly every pilot I know has a smart phone and could, at least theoretically, track their position by satellite with the right app. They would not be allowed to use it in justifying any flight decision they made, under any formal investigation; it would be uncertified equipment. Do many of them keep it turned on and glance at it anyway? Probably.
Nearly all US airlines have that capability already. They have been incentivized by better routings, extra altitudes available up high, better Go opportunities, and better safety margins reference other traffic detection. Airlines have absorbed the cost over the last 10 years (passing it to customers, of course) but I don't know the exact state of regulations on it (the FAA sets its own standards, which differ from ICAO in many ways) at this point in time. It's not required equipment in general aviation, but it's possible there's a roll-in by requirement (mandate) on US flag airlines by now to have a minimum GPS-capable system on board, probably on large jets if there's any mandate, probably not yet on the smaller air taxi and feeder airline airframes.
I can get back to you on that if you really want to know what's required.
Aircrews have to choose which instruments are reliable and which are not. Sure, take out a personal GPS and the right answer is instantly there but that is not on the checklist.
Pitot icing at high altitude and unreliable airspeed indications due to turbulence are practiced in simulators, but a good many other scenarios must be practiced also and pilots only get so much simulator time.
People make jokes that a teenager with a home computer and a good version of Flight Simulator might make a better pilot than some of those who are actually at the controls of an airliner, because the teenager has spent far more time actually flying the plane than the professional pilot has.
AF447 took four minutes. Was at night and started at a higher altitude. AirAsia was daylight, and started at lower altitude so there may well have been less than four minutes to figure out what was wrong and what to do.
GPS can't measure airspeed, as GPS does not know the wind speed or direction relative to the aircraft. GPS would provide a reasonable ground speed.Quote: DRichBabs, since there seem to be Pitot tubes icing up on many occasions, do the planes use GPS as a backup indicator for airspeed and altitude? I know my $99 Garmin shows both when driving.
Quote: LoquaciousMoFWGPS can't measure airspeed, as GPS does not know the wind speed or direction relative to the aircraft. GPS would provide a reasonable ground speed.
True dat. Edit: story time. Don't read if you don't like airplane stories. The short response to LMFW's comment is between the stars.
There's a thing that happens every year in Oregon and Washington, with the Columbia Gorge funneling air between the bluffs moving differently than air on the plateau, complicated further by the higher peaks (Cascades) and winds in from the Pacific. For about two weeks, they get 50 knot winds at sea level (the airport elevation is about 23 feet, along the Columbia River) from the south-southwest. When that happens, they usually have to use the crosswind runway for everybody including the biggest heavy jets.
They also have a few of the lighter aircraft, though the airport rules prohibit most smaller ones (they use two nearby GA airports). But when those winds come, (this was also apparent in Yakima, where I first worked) I've seen aircraft stand still, and even actually back up, indicating 0 or negative 10-20 on the radar, while they have 60 knots indicated airspeed on the nose keeping them flying. A few of them with small powerplants, like aircoupes or supercubs, can be firewalled and still be going backwards.
Early in my career, I was credited with a classic transmission. It came out sarcastic, though I didn't mean it that way. I had one of those supercubs trying to land while going backward on short final, and I said to him, "N22PP, will you be landing today?" Oops. (fictitious tail number). Was a running joke on me for several years.
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The right app could take your position and calculate it with a feed from your altimeter, winds aloft info (mostly large jets only have this) and other instrumentation from the flight management system and tell you indicated airspeed, which is how much headway you have to be making against the air mass you're in to stay flying, no matter how much ground you're covering. The technology does exist. But to my knowledge, all the instrumentation that allows translation to IAS (whether GPS supplemental is involved or not) is susceptible to ice. I don't think they've figured a way around that yet.
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Another controller-humor story about that crosswind runway. There are always flight-watchers along Marine Way, which is the narrow road between the north-most runway and the Columbia River in Portland. The end of the runway backs right up to that road, with an overrun pad in front of the approach end (it's called a displaced threshold). They work hard at NOT using that runway; it's short, noisy, and points right into the high ridge separating downtown from Beaverton. But during those seasonal winds, even the L1011's going to Asia had to use it.
The watchers often set up lawn chairs or picnics along the seawall and just hung out. It's a great place to watch airplanes safely during normal operations. But when the big Asia-bound jets use the crosswind runway for takeoff, they use the whole runway plus the overrun, which means spectators have 2 or 3 (or 4 when United still flew DC8's and UPS had B747's) engine butts staring them right in the face. At least once a year, some poor clueless souls would have set up to watch during this operation. Regular jets would put out just enough power from the normal start point for them to get a fun blast of air each time they left or arrived.
Not the big boys. They used every inch of the overrun, then they would stand on the brakes and apply full power while holding there to get maximum forward velocity before starting takeoff roll. They weighed about 400,000 pounds fully fueled and the runway was only 7000 feet long, so that was the only way they could get airborne, and they had to have 30 knots of crosswind before they would accept that runway. So when they did that, the people on the seawall got hit with multiple tornado-force blasts, and several times they got blown right off the wall into the river. We would watch through binoculars. It was hysterical, though I suppose more than a few got hurt. Never heard anyone got killed, though. I remember particularly one guy who somersaulted 3 times with his green aluminum lawn chair flying beside him as he went in.
I left in mid-93, but I'm guessing it wasn't too much later they totally prohibited people to be on that part of the seawall. No idea, but seems likely they had to stop it happening.
Aren't there some houseboats permanently moored near there? And a hoity-toity country-club/golf-course? Maybe the houseboats are a little further downriver, I'm not sure. But I'm picturing some interesting times for somebody relaxing on the deck of their floating home, or teeing up at the Edgewater Club, when they do that thing you just described.Quote: beachbumbabsThere are always flight-watchers along Marine Way, which is the narrow road between the north-most runway and the Columbia River in Portland. The end of the runway backs right up to that road,...
Quote: beachbumbabsSo when they did that, the people on the seawall got hit with multiple tornado-force blasts, and several times they got blown right off the wall into the river. We would watch through binoculars. It was hysterical, though I suppose more than a few got hurt. Never heard anyone got killed, though. I remember particularly one guy who somersaulted 3 times with his green aluminum lawn chair flying beside him as he went in.
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On the beach in St. Maarten (SXM) I have seen people blown into the water from the jet blast.
Quote: LoquaciousMoFWGPS can't measure airspeed, as GPS does not know the wind speed or direction relative to the aircraft. GPS would provide a reasonable ground speed.
Great point, I hadn't thought of that.
Quote: beachbumbabsI'll try not to get too far in the weeds (don't mean to be patronizing, just that I could write a book on this),
2. Thunderstorms go up 40-55 thousand feet, with further turbulence above that, around 5000 feet.
2a. The service ceiling of commercial airliners like the A320 stops around 39 thousand, or lower. They can't top the thunderstorms.
So, in this accident (I'm going to say this without all the info, and we'll see what they say in the investigation), the pilots did not declare an emergency or ask for priority, they waited too long to take action by deviating and got into the heart of the thunderstorm, the aircraft couldn't climb above the storm (it was reported tops at 55 thousand feet). It's likely the updrafts carried them higher anyway (they're indicating a climb), they had inaccurate info on their airspeed and/or altitude from iced instruments, and they didn't know how slow they were going, and they were in severe or extreme turbulence.
As a result of all these factors each taking their toll on airspeed, the wings stopped providing lift and they fell out of the sky either tail first, or one wing flew and the other didn't and they went into a spin and couldn't get the airframe to fly again or ran out of room. (The recovery would take full power, nose pointed down, correct any spin while in free-fall if this is what happened; they may have simply run out of altitude while trying to fly.) The airframe could have torn off a wing or two on the way down if their recovery effort overstressed the airframe, but more likely the aircraft broke on impact, either just ahead of or behind the wings.
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Hit the storm and climbed 5400 ft in 30 seconds until it stalled
http://www.cnn.com/2015/01/29/asia/airasia-disaster/index.html
