Aeronautical Insanity: switching to secondary tolerances

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Butt Reactor: Oct 6, 2005; Even in zero gravity, you're an asshole.

grover posted:

That's my thoughts as well. What's the standard height of a runway light?

average height of a taxiway/runway edge light is about 2' feet, the runway distance sign in the other picture is about 4x4 feet. In case you want a source: http://www.faa.gov/documentLibrary/media/Advisory_Circular/150_5345_44j.pdf

# ? Dec 9, 2011 08:34

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# ? May 22, 2024 18:49

Godholio: Aug 28, 2002; Does a bear split in the woods near Zheleznogorsk?

Tsuru posted:

Convince me of what, exactly? That it does not matter what size or colour it is? The thing with UAV designs is that they scale really really well to suit a particular task, because there is no fleshy bit in the front of a given size. This moves your design starting point to the designed range/fuel capacity and the amount of payload that it has to carry. Given that this particular example was flown from Afghanistan to Iran and not from a base in the USA like a Global Hawk or a Polecat actually convinces me that the size of this thing looks pretty spot-on. Its comparative size to the taxiway lights in the other pictures also confirms that the size matches.

As for the seams and the drapes, it simply makes it look like the Iranians propped up a damaged aircraft as best they could to convince people who are not familiar with aircraft that they captured a fully intact UAV, but it looks to me they are trying to hide the fact that this plane will never fly again, and that they failed to preserve its most valuable component, the sensor suite.

Except you're wrong.

Color does matter. Evidence!=proof. A stealth aircraft is coated with special paint. IT DOES NOT COME IN TAN. Tan would be a poor choice for aerial camouflage as well. There is no reason the USAF would go that route.

This thing is way too small to have a decent sensor suite or payload. This size would limit it to roughly the capability of a Predator/Reaper, which would be pretty ridiculous to spend the kind of time and money it would take to drop the RCS. There are smaller RCS systems that have similar sensor capabilities already in existence, this thing would be redundant. Not only that, the mockup Iran displayed isn't large enough for the engine. This alone should prove the point.

Wings don't break off along a seam like that. A wing also couldn't be held up by loving BONDO.

# ? Dec 9, 2011 12:03

grover: Jan 23, 2002; PEW PEW PEW

Butt Reactor posted:

average height of a taxiway/runway edge light is about 2' feet, the runway distance sign in the other picture is about 4x4 feet. In case you want a source: http://www.faa.gov/documentLibrary/media/Advisory_Circular/150_5345_44j.pdf

Well, assuming 2' lights and 4' signs, the runway photos set some upper/lower limits on the size of the RQ-170 as 9-13' tall, with a 72-104' wingspan. Guestimating the relative distances, I'd extrapolate somewhere around 85' wingspan.

# ? Dec 9, 2011 14:41

Tsuru: May 12, 2008

Godholio posted:

Except you're wrong.

Color does matter. Evidence!=proof. A stealth aircraft is coated with special paint. IT DOES NOT COME IN TAN. Tan would be a poor choice for aerial camouflage as well. There is no reason the USAF would go that route.

This thing is way too small to have a decent sensor suite or payload. This size would limit it to roughly the capability of a Predator/Reaper, which would be pretty ridiculous to spend the kind of time and money it would take to drop the RCS. There are smaller RCS systems that have similar sensor capabilities already in existence, this thing would be redundant. Not only that, the mockup Iran displayed isn't large enough for the engine. This alone should prove the point.

Wings don't break off along a seam like that. A wing also couldn't be held up by loving BONDO.

I don't think assumptions are proof either, but let's just wait and see. I'm sure in good time we'll know.

# ? Dec 9, 2011 15:48

Mr.Peabody: Jul 15, 2009

Godholio posted:

Except you're wrong.

Color does matter. Evidence!=proof. A stealth aircraft is coated with special paint. IT DOES NOT COME IN TAN. Tan would be a poor choice for aerial camouflage as well. There is no reason the USAF would go that route.

This thing is way too small to have a decent sensor suite or payload. This size would limit it to roughly the capability of a Predator/Reaper, which would be pretty ridiculous to spend the kind of time and money it would take to drop the RCS. There are smaller RCS systems that have similar sensor capabilities already in existence, this thing would be redundant. Not only that, the mockup Iran displayed isn't large enough for the engine. This alone should prove the point.

Wings don't break off along a seam like that. A wing also couldn't be held up by loving BONDO.

I'm pretty sure the bondo job on the wing was done by Iran in order to present it to the public as "whole and intact!"

e: The CIA has pretty much admitted they have one, I don't see why you're in a higher state of denial than the CIA, I didn't even think that was possible :psyboom:

Mr.Peabody fucked around with this message at 16:26 on Dec 9, 2011

# ? Dec 9, 2011 16:24

AzureSkys: Apr 27, 2003

Here's a video with a little more to look at than the previous stills
http://youtu.be/vorWHmk38yE

# ? Dec 9, 2011 16:47

Tremblay: Oct 8, 2002; More dog whistles than a Petco

Mr.Peabody posted:

I'm pretty sure the bondo job on the wing was done by Iran in order to present it to the public as "whole and intact!"

e: The CIA has pretty much admitted they have one, I don't see why you're in a higher state of denial than the CIA, I didn't even think that was possible

I'm sure they've recovered some wreckage. Those photos are not of that wreckage however.

# ? Dec 9, 2011 16:58

Godholio: Aug 28, 2002; Does a bear split in the woods near Zheleznogorsk?

Tsuru posted:

I don't think assumptions are proof either, but let's just wait and see. I'm sure in good time we'll know.

I'm not really making a lot of assumptions. That thing is too small to hold the engine that powers it.

I guess the paint thing is kind of an assumption, but it's based on my experience in the Air Force. I'm pretty confident about it.

I'm familiar with the sensor suites used on USAF UAVs. That thing isn't big enough to carry anything better than what the cheap/disposable UAV already carries.

# ? Dec 9, 2011 17:24

Cygni: Nov 12, 2005; raring to post

Godholio posted:

I'm not really making a lot of assumptions. That thing is too small to hold the engine that powers it.

I guess the paint thing is kind of an assumption, but it's based on my experience in the Air Force. I'm pretty confident about it.

I'm familiar with the sensor suites used on USAF UAVs. That thing isn't big enough to carry anything better than what the cheap/disposable UAV already carries.

Previous pictures show that its a correct color job, but of course, this could be an Iranian Maaco color match. The engine listed by Aviation Week was a guess before anyone had any hard measurements. It could just as easily be a PW600 series or something equally tiny.

I highly doubt you would take the time to develop a black project UAV operated by the CIA without having it operate a sensor suite worth flying, personally. Especially if the reports that the president was offered three strike options to destroy the drone are true. You wouldn't even consider that if its a predator-pack.

CIA has confirmed a lost drone, and hasn't done anything to say that the pictures are not legit. Seems pretty likely that they lost an RQ-170, that it probably came down hard, and that Iran has pieced together what they can while filling in the rest.

# ? Dec 9, 2011 17:47

smackfu: Jun 7, 2004

If we can check the drone color using Google, so can Iran.

# ? Dec 9, 2011 18:12

Tsuru: May 12, 2008

Godholio posted:

I'm not really making a lot of assumptions. That thing is too small to hold the engine that powers it.

I guess the paint thing is kind of an assumption, but it's based on my experience in the Air Force. I'm pretty confident about it.

I'm familiar with the sensor suites used on USAF UAVs. That thing isn't big enough to carry anything better than what the cheap/disposable UAV already carries.

As much as I hate to point out the obvious, and as incomprehensible as this concept may be to a proud American such as yourself: bigger is not necessarily better.

# ? Dec 9, 2011 19:40

Tremblay: Oct 8, 2002; More dog whistles than a Petco

Tsuru posted:

As much as I hate to point out the obvious, and as incomprehensible as this concept may be to a proud American such as yourself: bigger is not necessarily better.

Really dude? He's in a good position to be making comments.

# ? Dec 9, 2011 19:45

Cygni: Nov 12, 2005; raring to post

Tsuru posted:

As much as I hate to point out the obvious, and as incomprehensible as this concept may be to a proud American such as yourself: bigger is not necessarily better.

Is this a burn or something, it doesn't even... make sense? He's saying the engine AW listed in it wouldnt fit in the Iranian display, which is true?

# ? Dec 9, 2011 19:46

Tsuru: May 12, 2008

Tremblay posted:

Really dude? He's in a good position to be making comments.

Maybe he's not the only one, but perhaps others might not be so tempted to engage in internet willy-waving.

It was an attempt at humour, but let's just forget about it before more egos are harmed.

Tsuru fucked around with this message at 19:59 on Dec 9, 2011

# ? Dec 9, 2011 19:53

Previa_fun: Nov 10, 2004

I can believe that maybe it was damaged enough that they just put a coat of paint on it and bondo'd it enough to look "presentable."

My issue is the size: IF it's really powered by the TF34 like everyone says, I have no idea where one of those would fit in there:

http://en.wikipedia.org/wiki/General_Electric_TF34

Then again, it's ~~entirely possible~~ very likely it has a different and much smaller engine anyway so that doesn't necessarily prove anything.

Previa_fun fucked around with this message at 17:57 on Dec 11, 2011

# ? Dec 9, 2011 20:57

slidebite: Nov 6, 2005; Good egg

Godholio posted:

I'm not really making a lot of assumptions. That thing is too small to hold the engine that powers it.

It does seem small, but I'm not convinced it's too small to hold the engine. I think it looks smaller than it really is.

To be clear, I am far from sold that's the genuine article, but I don't think it's as painfully obvious as some say it is that it isn't.

# ? Dec 9, 2011 21:11

slidebite: Nov 6, 2005; Good egg

Crosspost from GBS:

http://www.space.com/13879-spacex-dragon-space-station-launch-date-announced.html

quote:

NASA announced the launch date for the first test flight of a commercial spacecraft to the International Space Station today (Dec. 9). The mission, which will test a vehicle intended to carry cargo, and eventually crew, to orbit, represents an important step for the burgeoning private space industry, experts say.

NASA gave Space Exploration Technologies (SpaceX) the formal go-ahead to launch its robotic Dragon spacecraft atop a SpaceX Falcon 9 rocket to the space station on Feb. 7, 2012, so long as a series of final safety reviews, testing and verification is successfully completed.

This is very good news.

# ? Dec 9, 2011 21:44

Styles Bitchley: Nov 13, 2004; FOR THE WIN FOR THE WIN FOR THE WIN

slidebite posted:

Crosspost from GBS:

http://www.space.com/13879-spacex-dragon-space-station-launch-date-announced.html

This is very good news.

Yes, especially after having to go through another JWST hearing this week. Glad they are combining the mission, wonder how dicey that will be for the ISS crew. No doubt game faces all around when that goes on. I don't think people realize how dangerous it is up there, and hopefully we won't be reminded anytime soon.

# ? Dec 9, 2011 22:11

Cygni: Nov 12, 2005; raring to post

AW has got a big article up. The consensus is that Goholio was right about the sensor package, nothing really that fancy so nobody is really that worried about that aspect. Although if the Chinese or Russians get a hold of the whole airframe, they might be a little more concerned.

http://www.aviationweek.com/aw/generic/story_generic.jsp?channel=awst&id=news/awst/2011/12/12/AW_12_12_2011_p19-402987.xml

# ? Dec 9, 2011 23:49

Godholio: Aug 28, 2002; Does a bear split in the woods near Zheleznogorsk?

Well drat. I'll only take partial credit on that. I figured if they were going to go to the trouble building a system like this they'd put something bigger than FMV/Pred pods on it.

Still looks crazy loving small for a TF34-powered aircraft, though.

# ? Dec 10, 2011 00:46

Bondematt: Jan 26, 2007; Not too stupid

Godholio posted:

Well drat. I'll only take partial credit on that. I figured if they were going to go to the trouble building a system like this they'd put something bigger than FMV/Pred pods on it.

Still looks crazy loving small for a TF34-powered aircraft, though.

According to Wiki it could also be powered by the Garrett TFE731, but I don't know if the citation they have on the TF34 is for both or what. Those engines are crazy different in size though, the 731 being about half the length.

# ? Dec 10, 2011 01:02

slidebite: Nov 6, 2005; Good egg

Styles Bitchley posted:

Yes, especially after having to go through another JWST hearing this week. Glad they are combining the mission, wonder how dicey that will be for the ISS crew. No doubt game faces all around when that goes on. I don't think people realize how dangerous it is up there, and hopefully we won't be reminded anytime soon.

Sounds like they're going to get it into station keeping for a while to check everything out before they let it get too close. But yeah, the first time will be a real nail biter for sure.

# ? Dec 10, 2011 01:05

slidebite: Nov 6, 2005; Good egg

Well, I just read one of the most heartbreaking things I've read in a while, the cockpit transcript of AF447.

Seems like a bit of icing, a whole shitload of confusion and forgetting how to fly a plane and just coming to grips with it seconds after it was too late was the root of it.

quote:

At 1h 36m, the flight enters the outer extremities of a tropical storm system. Unlike other planes' crews flying through the region, AF447's flight crew has not changed the route to avoid the worst of the storms. The outside temperature is much warmer than forecast, preventing the still fuel-heavy aircraft from flying higher to avoid the effects of the weather. Instead, it ploughs into a layer of clouds.

At 1h51m, the cockpit becomes illuminated by a strange electrical phenomenon. The co-pilot in the right-hand seat, an inexperienced 32-year-old named Pierre-C�dric Bonin, asks, "What's that?" The captain, Marc Dubois, a veteran with more than 11,000 hours of flight time, tells him it is St. Elmo's fire, a phenomenon often found with thunderstorms at these latitudes.

At approximately 2 am, the other co-pilot, David Robert, returns to the cockpit after a rest break. At 37, Robert is both older and more experienced than Bonin, with more than double his colleague's total flight hours. The head pilot gets up and gives him the left-hand seat. Despite the gap in seniority and experience, the captain leaves Bonin in charge of the controls.

At 2:02 am, the captain leaves the flight deck to take a nap. Within 15 minutes, everyone aboard the plane will be dead.]

02:03:44 (Bonin) La convergence inter tropicale� voil�, l� on est dedans, entre 'Salpu' et 'Tasil.' Et puis, voil�, on est en plein dedans�
The inter-tropical convergence... look, we're in it, between 'Salpu' and 'Tasil.' And then, look, we're right in it...

The intertropical convergence, or ITC, is an area of consistently severe weather near the equator. As is often the case, it has spawned a string of very large thunderstorms, some of which stretch into the stratosphere. Unlike some of the other planes's crews flying in the region this evening, the crew of AF447 has not studied the pattern of storms and requested a divergence around the area of most intense activity. (Salpu and Tasil are two air-traffic-position reporting points.)

02:05:55 (Robert) Oui, on va les appeler derri�re... pour leur dire quand m�me parce que...
Yes, let's call them in the back, to let them know...

Robert pushes the call button.

02:05:59 (flight attendant, heard on the intercom) Oui? Marilyn.
Yes? Marilyn.

02:06:04 (Bonin) Oui, Marilyn, c'est Pierre devant... Dis-moi, dans deux minutes, on devrait attaquer une zone o� �a devrait bouger un peu plus que maintenant. Il faudrait vous m�fier l�.
Yes, Marilyn, it's Pierre up front... Listen, in 2 minutes, we're going to be getting into an area where things are going to be moving around a little bit more than now. You'll want to take care.

02:06:13 (flight attendant) D'accord, on s'assoit alors?
Okay, we should sit down then?

02:06:15 (Bonin) Bon, je pense que ce serait pas mal� tu pr�viens les copains!
Well, I think that's not a bad idea. Give your friends a heads-up.

02:06:18 (flight attendant) Ouais, OK, j'appelle les autres derri�re. Merci beaucoup.
Yeah, okay, I'll tell the others in the back. Thanks a lot.

02:06:19 (Bonin) Mais je te rappelle d�s qu'on est sorti de l�.
I'll call you back as soon as we're out of it.

02:06:20 (flight attendant) OK.
Okay.

The two copilots discuss the unusually elevated external temperature, which has prevented them from climbing to their desired altitude, and express happiness that they are flying an Airbus 330, which has better performance at altitude than an Airbus 340.

02:06:50 (Bonin) Va pour les anti-ice. C'est toujours �a de pris.
Let's go for the anti-icing system. It's better than nothing.

Because they are flying through clouds, the pilots turn on the anti-icing system to try to keep ice off the flight surfaces; ice reduces the plane's aerodynamic efficiency, weighs it down, and in extreme cases, can cause it to crash.

02:07:00 (Bonin) On est apparemment � la limite de la couche, �a devrait aller.
We seem to be at the end of the cloud layer, it might be okay.

In the meantime Robert has been examining the radar system and has found that it has not been set up in the correct mode. Changing the settings, he scrutinizes the radar map and realizes that they are headed directly toward an area of intense activity.

02:08:03 (Robert) Tu peux �ventuellement le tirer un peu � gauche.
You can possibly pull it a little to the left.

02:08:05 (Bonin) Excuse-moi?
Sorry, what?

02:08:07 (Robert) Tu peux �ventuellement prendre un peu � gauche. On est d'accord qu'on est en manuel, hein?
You can possibly pull it a little to the left. We're agreed that we're in manual, yeah?

Bonin wordlessly banks the plane to the left. Suddenly, a strange aroma, like an electrical transformer, floods the cockpit, and the temperature suddenly increases. At first, the younger pilot thinks that something is wrong with the air-conditioning system, but Robert assures him that the effect is from the severe weather in the vicinity. Bonin seems ill at ease. Then the sound of slipstream suddenly becomes louder. This, presumably, is due to the accumulation of ice crystals on the exterior of the fuselage. Bonin announces that he is going to reduce the speed of the aircraft, and asks Robert if he should turn on a feature that will prevent the jet engines from flaming out in the event of severe icing.

Just then an alarm sounds for 2.2 seconds, indicating that the autopilot is disconnecting. The cause is the fact that the plane's pitot tubes, externally mounted sensors that determine air speed, have iced over, so the human pilots will now have to fly the plane by hand.

Note, however, that the plane has suffered no mechanical malfunction. Aside from the loss of airspeed indication, everything is working fine. Otelli reports that many airline pilots (and, indeed, he himself) subsequently flew a simulation of the flight from this point and were able to do so without any trouble. But neither Bonin nor Roberts has ever received training in how to deal with an unreliable airspeed indicator at cruise altitude, or in flying the airplane by hand under such conditions.

02:10:06 (Bonin) J'ai les commandes.
I have the controls.

02:10:07 (Robert) D'accord.
Okay.

Perhaps spooked by everything that has unfolded over the past few minutes�the turbulence, the strange electrical phenomena, his colleague's failure to route around the potentially dangerous storm�Bonin reacts irrationally. He pulls back on the side stick to put the airplane into a steep climb, despite having recently discussed the fact that the plane could not safely ascend due to the unusually high external temperature.

Bonin's behavior is difficult for professional aviators to understand. "If he's going straight and level and he's got no airspeed, I don't know why he'd pull back," says Chris Nutter, an airline pilot and flight instructor. "The logical thing to do would be to cross-check"�that is, compare the pilot's airspeed indicator with the co-pilot's and with other instrument readings, such as groundspeed, altitude, engine settings, and rate of climb. In such a situation, "we go through an iterative assessment and evaluation process," Nutter explains, before engaging in any manipulation of the controls. "Apparently that didn't happen."

Almost as soon as Bonin pulls up into a climb, the plane's computer reacts. A warning chime alerts the cockpit to the fact that they are leaving their programmed altitude. Then the stall warning sounds. This is a synthesized human voice that repeatedly calls out, "Stall!" in English, followed by a loud and intentionally annoying sound called a "cricket." A stall is a potentially dangerous situation that can result from flying too slowly. At a critical speed, a wing suddenly becomes much less effective at generating lift, and a plane can plunge precipitously. All pilots are trained to push the controls forward when they're at risk of a stall so the plane will dive and gain speed.

The Airbus's stall alarm is designed to be impossible to ignore. Yet for the duration of the flight, none of the pilots will mention it, or acknowledge the possibility that the plane has indeed stalled�even though the word "Stall!" will blare through the cockpit 75 times. Throughout, Bonin will keep pulling back on the stick, the exact opposite of what he must do to recover from the stall.

02:10:07 (Robert) Qu'est-ce que c'est que �a?
What's this?

02:10:15 (Bonin) On n'a pas une bonne� On n'a pas une bonne annonce de vitesse.
There's no good... there's no good speed indication.

02:10:16 (Robert) On a perdu les, les, les vitesses alors?
We've lost the, the, the speeds, then?

The plane is soon climbing at a blistering rate of 7000 feet per minute. While it is gaining altitude, it is losing speed, until it is crawling along at only 93 knots, a speed more typical of a small Cessna than an airliner. Robert notices Bonin's error and tries to correct him.

02:10:27 (Robert) Faites attention � ta vitesse. Faites attention � ta vitesse.
Pay attention to your speed. Pay attention to your speed.

He is probably referring to the plane's vertical speed. They are still climbing.

02:10:28 (Bonin) OK, OK, je redescends.
Okay, okay, I'm descending.

02:10:30 (Robert) Tu stabilises...
Stabilize�

02:10:31 (Bonin) Ouais.
Yeah.

02:10:31 (Robert) Tu redescends... On est en train de monter selon lui� Selon lui, tu montes, donc tu redescends.
Descend... It says we're going up... It says we're going up, so descend.

02:10:35 (Bonin) D'accord.
Okay.

Thanks to the effects of the anti-icing system, one of the pitot tubes begins to work again. The cockpit displays once again show valid speed information.

02:10:36 (Robert) Redescends!
Descend!

02:10:37 (Bonin) C'est parti, on redescend.
Here we go, we're descending.

02:10:38 (Robert) Doucement!
Gently!

Bonin eases the back pressure on the stick, and the plane gains speed as its climb becomes more shallow. It accelerates to 223 knots. The stall warning falls silent. For a moment, the co-pilots are in control of the airplane.

02:10:41(Bonin) On est en� ouais, on est en "climb."
We're... yeah, we're in a climb.

Yet, still, Bonin does not lower the nose. Recognizing the urgency of the situation, Robert pushes a button to summon the captain.

02:10:49 (Robert) Putain, il est o�... euh?
drat it, where is he?

The plane has climbed to 2512 feet above its initial altitude, and though it is still ascending at a dangerously high rate, it is flying within its acceptable envelope. But for reasons unknown, Bonin once again increases his back pressure on the stick, raising the nose of the plane and bleeding off speed. Again, the stall alarm begins to sound.

Still, the pilots continue to ignore it, and the reason may be that they believe it is impossible for them to stall the airplane. It's not an entirely unreasonable idea: The Airbus is a fly-by-wire plane; the control inputs are not fed directly to the control surfaces, but to a computer, which then in turn commands actuators that move the ailerons, rudder, elevator, and flaps. The vast majority of the time, the computer operates within what's known as normal law, which means that the computer will not enact any control movements that would cause the plane to leave its flight envelope. "You can't stall the airplane in normal law," says Godfrey Camilleri, a flight instructor who teaches Airbus 330 systems to US Airways pilots.

But once the computer lost its airspeed data, it disconnected the autopilot and switched from normal law to "alternate law," a regime with far fewer restrictions on what a pilot can do. "Once you're in alternate law, you can stall the airplane," Camilleri says.

It's quite possible that Bonin had never flown an airplane in alternate law, or understood its lack of restrictions. According to Camilleri, not one of US Airway's 17 Airbus 330s has ever been in alternate law. Therefore, Bonin may have assumed that the stall warning was spurious because he didn't realize that the plane could remove its own restrictions against stalling and, indeed, had done so.

02:10:55 (Robert) Putain!
drat it!

Another of the pitot tubes begins to function once more. The cockpit's avionics are now all functioning normally. The flight crew has all the information that they need to fly safely, and all the systems are fully functional. The problems that occur from this point forward are entirely due to human error.

02:11:03 (Bonin) Je suis en TOGA, hein?
I'm in TOGA, huh?

Bonin's statement here offers a crucial window onto his reasoning. TOGA is an acronym for Take Off, Go Around. When a plane is taking off or aborting a landing�"going around"�it must gain both speed and altitude as efficiently as possible. At this critical phase of flight, pilots are trained to increase engine speed to the TOGA level and raise the nose to a certain pitch angle.

Clearly, here Bonin is trying to achieve the same effect: He wants to increase speed and to climb away from danger. But he is not at sea level; he is in the far thinner air of 37,500 feet. The engines generate less thrust here, and the wings generate less lift. Raising the nose to a certain angle of pitch does not result in the same angle of climb, but far less. Indeed, it can�and will�result in a descent.

While Bonin's behavior is irrational, it is not inexplicable. Intense psychological stress tends to shut down the part of the brain responsible for innovative, creative thought. Instead, we tend to revert to the familiar and the well-rehearsed. Though pilots are required to practice hand-flying their aircraft during all phases of flight as part of recurrent training, in their daily routine they do most of their hand-flying at low altitude�while taking off, landing, and maneuvering. It's not surprising, then, that amid the frightening disorientation of the thunderstorm, Bonin reverted to flying the plane as if it had been close to the ground, even though this response was totally ill-suited to the situation.

02:11:06 (Robert) Putain, il vient ou il vient pas?
drat it, is he coming or not?

The plane now reaches its maximum altitude. With engines at full power, the nose pitched upward at an angle of 18 degrees, it moves horizontally for an instant and then begins to sink back toward the ocean.

02:11:21 (Robert) On a pourtant les moteurs! Qu'est-ce qui se passe bordel? Je ne comprends pas ce que se passe.
We still have the engines! What the hell is happening? I don't understand what's happening.

Unlike the control yokes of a Boeing jetliner, the side sticks on an Airbus are "asynchronous"�that is, they move independently. "If the person in the right seat is pulling back on the joystick, the person in the left seat doesn't feel it," says Dr. David Esser, a professor of aeronautical science at Embry-Riddle Aeronautical University. "Their stick doesn't move just because the other one does, unlike the old-fashioned mechanical systems like you find in small planes, where if you turn one, the [other] one turns the same way." Robert has no idea that, despite their conversation about descending, Bonin has continued to pull back on the side stick.

The men are utterly failing to engage in an important process known as crew resource management, or CRM. They are failing, essentially, to cooperate. It is not clear to either one of them who is responsible for what, and who is doing what. This is a natural result of having two co-pilots flying the plane. "When you have a captain and a first officer in the cockpit, it's clear who's in charge," Nutter explains. "The captain has command authority. He's legally responsible for the safety of the flight. When you put two first officers up front, it changes things. You don't have the sort of traditional discipline imposed on the flight deck when you have a captain."

The vertical speed toward the ocean accelerates. If Bonin were to let go of the controls, the nose would fall and the plane would regain forward speed. But because he is holding the stick all the way back, the nose remains high and the plane has barely enough forward speed for the controls to be effective. As turbulence continues to buffet the plane, it is nearly impossible to keep the wings level.

02:11:32 (Bonin) Putain, j'ai plus le contr�le de l'avion, l�! J'ai plus le contr�le de l'avion!
drat it, I don't have control of the plane, I don't have control of the plane at all!

02:11:37 (Robert) Commandes � gauche!
Left seat taking control!

At last, the more senior of the pilots (and the one who seems to have a somewhat better grasp of the situation) now takes control of the airplane. Unfortunately, he, too, seems unaware of the fact that the plane is now stalled, and pulls back on the stick as well. Although the plane's nose is pitched up, it is descending at a 40-degree angle. The stall warning continues to sound. At any rate, Bonin soon after takes back the controls.

A minute and a half after the crisis began, the captain returns to the cockpit. The stall warning continues to blare.

02:11:43 (Captain) Eh� Qu'est-ce que vous foutez?
What the hell are you doing?

02:11:45 (Bonin) On perd le contr�le de l'avion, l�!
We've lost control of the plane!

02:11:47 (Robert) On a totalement perdu le contr�le de l'avion... On comprend rien... On a tout tent�...
We've totally lost control of the plane. We don't understand at all... We've tried everything.

By now the plane has returned to its initial altitude but is falling fast. With its nose pitched 15 degrees up, and a forward speed of 100 knots, it is descending at a rate of 10,000 feet per minute, at an angle of 41.5 degrees. It will maintain this attitude with little variation all the way to the sea. Though the pitot tubes are now fully functional, the forward airspeed is so low�below 60 knots�that the angle-of-attack inputs are no longer accepted as valid, and the stall-warning horn temporarily stops. This may give the pilots the impression that their situation is improving, when in fact it signals just the reverse.

Another of the revelations of Otelli's transcript is that the captain of the flight makes no attempt to physically take control of the airplane. Had Dubois done so, he almost certainly would have understood, as a pilot with many hours flying light airplanes, the insanity of pulling back on the controls while stalled. But instead, he takes a seat behind the other two pilots.

This, experts say, is not so hard to understand. "They were probably experiencing some pretty wild gyrations," Esser says. "In a condition like that, he might not necessarily want to make the situation worse by having one of the crew members actually disengage and stand up. He was probably in a better position to observe and give his commands from the seat behind."

But from his seat, Dubois is unable to infer from the instrument displays in front of him why the plane is behaving as it is. The critical missing piece of information: the fact that someone has been holding the controls all the way back for virtually the entire time. No one has told Dubois, and he hasn't thought to ask.

02:12:14 (Robert) Qu'est-ce que tu en penses? Qu'est-ce que tu en penses? Qu'est-ce qu'il faut faire?
What do you think? What do you think? What should we do?

02:12:15 (Captain) Alors, l�, je ne sais pas!
Well, I don't know!

As the stall warning continues to blare, the three pilots discuss the situation with no hint of understanding the nature of their problem. No one mentions the word "stall." As the plane is buffeted by turbulence, the captain urges Bonin to level the wings�advice that does nothing to address their main problem. The men briefly discuss, incredibly, whether they are in fact climbing or descending, before agreeing that they are indeed descending. As the plane approaches 10,000 feet, Robert tries to take back the controls, and pushes forward on the stick, but the plane is in "dual input" mode, and so the system averages his inputs with those of Bonin, who continues to pull back. The nose remains high.

02:13:40 (Robert) Remonte... remonte... remonte... remonte...
Climb... climb... climb... climb...

02:13:40 (Bonin) Mais je suis � fond � cabrer depuis tout � l'heure!
But I've had the stick back the whole time!

At last, Bonin tells the others the crucial fact whose import he has so grievously failed to understand himself.

02:13:42 (Captain) Non, non, non... Ne remonte pas... non, non.
No, no, no... Don't climb... no, no.

02:13:43 (Robert) Alors descends... Alors, donne-moi les commandes... � moi les commandes!
Descend, then... Give me the controls... Give me the controls!

Bonin yields the controls, and Robert finally puts the nose down. The plane begins to regain speed. But it is still descending at a precipitous angle. As they near 2000 feet, the aircraft's sensors detect the fast-approaching surface and trigger a new alarm. There is no time left to build up speed by pushing the plane's nose forward into a dive. At any rate, without warning his colleagues, Bonin once again takes back the controls and pulls his side stick all the way back.

02:14:23 (Robert) Putain, on va taper... C'est pas vrai!
drat it, we're going to crash... This can't be happening!

02:14:25 (Bonin) Mais qu'est-ce que se passe?
But what's happening?

02:14:27 (Captain) 10 degr�s d'assiette...
Ten degrees of pitch...

Exactly 1.4 seconds later, the cockpit voice recorder stops

Edit: After not before

slidebite fucked around with this message at 03:49 on Dec 10, 2011

# ? Dec 10, 2011 03:40

Phanatic: Mar 13, 2007; Please don't forget that I am an extremely racist idiot who also has terrible opinions about the Culture series.

slidebite posted:

Well, I just read one of the most heartbreaking things I've read in a while, the cockpit transcript of AF447.

Seems like a bit of icing, a whole shitload of confusion and forgetting how to fly a plane and just coming to grips with it seconds before it was too late was the root of it.

I can't figure out how Bonin was able to tie his shoes without a full-authority digital Shoelace Control System.

# ? Dec 10, 2011 03:46

Ridge_Runner_5: May 26, 2011; by Y Kant Ozma Post

That is utterly terrifying. It sounds like Bonin's mind shut down and he didn't think enough to realize he needs to push forward.

This should have been obvious once he regained his airspeed readings. The human brain does strange things under intense stress, though. Sadly, many people had to die because Bonin froze up.

# ? Dec 10, 2011 03:56

The Locator: Sep 12, 2004; Out here, everything hurts.

What is really amazing, is that all three pilots completely tuned out the stall warning. During the entire sequence, the airplane was loving telling them what was happening, and they completely ignored it.

Also, the lack of feedback between the two sticks seems (now, in retrospect) to be a pretty dumb thing. If the left seater had been unable to push his stick forward without a lot of effort, he might have clued into the fact that Bonin was literally stalling them into the ocean the entire time.

# ? Dec 10, 2011 04:01

movax: Aug 30, 2008

Ridge_Runner_5 posted:

That is utterly terrifying. It sounds like Bonin's mind shut down and he didn't think enough to realize he needs to push forward.

This should have been obvious once he regained his airspeed readings. The human brain does strange things under intense stress, though. Sadly, many people had to die because Bonin froze up.

I wonder how his family feels about that transcript being released. Also, I am surprised by the lack of haptic feedback offered up by Airbus...might have revealed to the other pilot that Bodin had brain-locked and hauled back on the control stick for the duration of the event.

That's the worst part, I think..."I don't know why this is happening, I've had the stick pulled back all this time!"
:psypop:

"WHAT NO"

e: ^^ beaten, and also yes, surprised by ignoring the stall alarm screaming. Some serious CRM failure up there on the flight deck, and interesting psychological effects at play

movax fucked around with this message at 04:05 on Dec 10, 2011

# ? Dec 10, 2011 04:02

Phanatic: Mar 13, 2007; Please don't forget that I am an extremely racist idiot who also has terrible opinions about the Culture series.

Ridge_Runner_5 posted:

That is utterly terrifying. It sounds like Bonin's mind shut down and he didn't think enough to realize he needs to push forward.

This should have been obvious once he regained his airspeed readings. The human brain does strange things under intense stress, though. Sadly, many people had to die because Bonin froze up.

There's more to it than that. First, you should never ignore a stall warning. Second, they shouldn't have such rock-solid faith that the normal-mode FCS won't let the pilot stall the airplane that it honestly doesn't even occur to them that the warning's a legitimate alarm. Third, the notion of a stall warning if the FCS is in normal-mode and will actually prevent a stall doesn't make a whole lot of sense from the standpoint of user interface design: "Stall! *chirpchirpchirp* Stall! *chirpchirpchirp*" shouldn't mean "Hi there! This is just a friendly reminder that you're doing something really dumb with the stick, and the plane would be falling out of the sky right now if I hadn't overridden your control inputs. Have a nice day!" Fourth, the pilots should be *able* to stall the aircraft in normal law; they might not ever want to actually do so, but they should still have to consider "Will what I'm about to do cause a stall?" Fifth, nobody in that cockpit knew how the damned FCS worked, they didn't understand that, hey, without airspeed, they're not in normal law anymore, and *all kinds of lights* go on when you're in alternate law. Sixth, the lack of cross-feedback between the sidesticks, the fact that the guy in the right seat can be pulling the nose all the way the hell up and the left-seater doesn't even feel it; if there was any sort of link between the two, left-seat is going to notice right away that right-seat's pulling on his stick for all it's worth. Hell, on a plane with yokes, he'd have the yoke jammed into his stomach, which would be a clue (yes, it's really not tractable to mechanically-couple sidesticks in a reliable fashion the way you can with a conventional yoke or a center stick. You could implement an electrically-driven force-feedback system but that likely causes additional places for poo poo to break; this might be an indication that conventional control mechanisms are superior to sidesticks as a UI).

I'm curious about how much time these guys had in-type, even the veteran with 11,000 hours who was taking a nap until a couple of minutes before the plane hit the ocean.

# ? Dec 10, 2011 04:09

Bondematt: Jan 26, 2007; Not too stupid

If he let go of the stick the Airbus would have corrected itself. The airplane design is dynamically stable.

Icing was almost a non-factor in this, other than it's psychological effects.

He stopped gathering data once he realized they were descending. Never cross checked his other gauges or noticed the steep angle at this altitude they could not climb.

Airbus is going to have some splainin' to do on how their system allows pilots to make inputs without showing the other pilot. Also not requiring pilots to be taught on alternate laws, and never to fully trust the auto-systems.

Air France will need to go retrain all of it's airbus pilots with this 'new' information and will likely take a good portion of the blame for not training well in the first place.

This whole thing screams Normal Accidents http://www.ohio.edu/people/piccard/entropy/perrow.html

They were set up for this accident before they took off, and Bronin was only a part of it. I really want to see how juicy this report is. It is a human factors accident that occurred due to a poorly designed system and lack of training. Any pilot would tell you to push the stick forward if in a stall, except an Airbus pilot who doesn't understand the system(lack of training) and has too much trust in it(lack of experience).

# ? Dec 10, 2011 06:33

kill me now: Sep 14, 2003; Why's Hank crying?

'CUZ HE JUST GOT DUNKED ON!

Its just staggering that the three of them managed to blow through nearly 36,000 feet of altitude before figuring out what was wrong. You can understand when things start going awry at lower altitudes and the pilots are not able to adjust in time, but they were above their regular crusing altitude and maintained their complete lack of situational awareness (despite having full insturments for almost all of the ordeal and having airbus's version of bitchen betty yelling at them for most of it) for nearly 4 minutes of "flight".

# ? Dec 10, 2011 18:09

Alpine Mustache: Jul 11, 2000

Is there something about the Airbus FCS that makes pulling back on the stick during a stall the correct thing to do? Or was his brain just totally hosed?
I know that if you fly into a cloud, the lack of any outside references can be very disorienting for some people, may he felt like the nose was dropping rapidly when it really wasn't.

Shouldn't there be an attitude indicator/artificial horizon in the cockpit that any one of them could have looked at to try and get the plane leveled out?

I was also confused while reading the whole thing because until now i didn't realize airbus had fighter-jet style control sticks instead of a more traditional yoke(yolk?), and i couldn't understand how the 2nd pilot couldn't tell the first pilot had the stick pulled back the whole time?

Hasn't Airbus' lack of automatically moving throttles contributed to accidents in the past? and now the lack of a moving stick is a factor in this one? Does a side-stick really offer any advantage over a yoke?

Alpine Mustache fucked around with this message at 19:11 on Dec 10, 2011

# ? Dec 10, 2011 19:09

The Ferret King: Nov 23, 2003; cluck cluck

Alpine Mustache posted:

Is there something about the Airbus FCS that makes pulling back on the stick during a stall the correct thing to do?

Nope, this was 100% the wrong input to make and he made it for the entire duration of the accident sequence, defying all logic.

quote:

I know that if you fly into a cloud, the lack of any outside references can be very disorienting for some people, may he felt like the nose was dropping rapidly when it really wasn't.

Possible, but the entire purpose of obtaining an instrument rating is to train yourself to fly by instruments and not by feeling when inside clouds. As experienced as this aircrew was, spatial disorientation should not have been a factor. That's more of something that comes up with sub 100 hr private instrument pilots. An experienced commercial aircrew should not be vulnerable to that kind of stimulus. Not saying it didn't happen, but it SHOULDN'T when your combined aircrew experience is 50,000+ hours or whatever.

quote:

Shouldn't there be an attitude indicator/artificial horizon in the cockpit that any one of them could have looked at to try and get the plane leveled out?

There was, they ignored it. They also ignored the airspeed indicator when it returned to functionality, indicating that they were slowing down (this indicates a climb, especially when cross referenced with the altimeter and Vertical Speed Indicator). They failed to properly absorb what their instruments were telling them.

quote:

I was also confused while reading the whole thing because until now i didn't realize airbus had fighter-jet style control sticks instead of a more traditional yoke(yolk?), and i couldn't understand how the 2nd pilot couldn't tell the first pilot had the stick pulled back the whole time?

Until today I didn't realize those side sticks weren't linked. I don't think side sticks are inherently more dangerous than a traditional Yoke, but I'm surprised to know that Airbus pilots have no idea what their buddy is doing on the controls, without visually checking.

# ? Dec 10, 2011 20:01

MrChips: Jun 10, 2005; FLIGHT SAFETY TIP: Fatties out first

Lots of misconceptions about the Air France accident here - if I wasn't limited to my phone right now, I would explain what they are and why they aren't correct. I'll probably do that sometime in the next couple of days, when I get some time.

I will say this much; one of my primary responsibilities at work is flight safety, and in my reviews of aircraft accidents, I have never seen an accident that has baffled and confused me as much as this one.

# ? Dec 10, 2011 20:03

Tsuru: May 12, 2008

Bondematt posted:

If he let go of the stick the Airbus would have corrected itself. The airplane design is dynamically stable.

The airplane initially thought it was overspeeding, so the flight directors commanded a nose-up attitude, which the pilots followed. The crew pulling back on the sticks caused the horizontal stabilizer to autotrim fully up (+14deg if I recall correctly). After this point simply letting go would not have saved them, recovery would have required the crew to push the nose hard down. Don't forget the aircraft also had a very rearwards CG for slightly lower fuel burn in cruise, at 28-29%.

I'm not even sure if at any point they realized their THS was trimmed all the way up.

# ? Dec 10, 2011 20:45

karoshi: Nov 4, 2008; "Can somebody mspaint eyes on the steaming packages? TIA" yeah well fuck you too buddy, this is the best you're gonna get. Is this even "work-safe"? Let's find out!

I read the post yesterday, this is my calmed down reply:
The accident report and cockpit transcript make me loving angry. He was not a pilot, he didn't understand how a loving plane flies. That idiot thought he was flying an UFO or a fighter jet with a thrust to weight ratio over 1. His lack of communication is inexcusable, taking over control on your own because you think you are right and not communicating what the gently caress you are doing is inexcusable. He reminds of some people I've worked with that were utter morons and a liability (not a risk industry, so just wasted time).

I agree that this was an airbus accident waiting to happen, linked haptic feedback would have a been a life saver and a "moron-check" safety measure, bypassing the need for explicit communication (something that moron was not capable of).

In summary, why was someone that doesn't understand that "pulling at the stick during 4 minutes = bad" in a cockpit? gently caress. Root cause: pilot education failure.

# ? Dec 10, 2011 21:17

Phanatic: Mar 13, 2007; Please don't forget that I am an extremely racist idiot who also has terrible opinions about the Culture series.

Tsuru posted:

The airplane initially thought it was overspeeding, so the flight directors commanded a nose-up attitude, which the pilots followed.

That's not what the article says.

quote:

Just then an alarm sounds for 2.2 seconds, indicating that the autopilot is disconnecting. The cause is the fact that the plane's pitot tubes, externally mounted sensors that determine air speed, have iced over, so the human pilots will now have to fly the plane by hand.

Note, however, that the plane has suffered no mechanical malfunction. Aside from the loss of airspeed indication, everything is working fine.

[...]

Perhaps spooked by everything that has unfolded over the past few minutes�the turbulence, the strange electrical phenomena, his colleague's failure to route around the potentially dangerous storm�Bonin reacts irrationally. He pulls back on the side stick to put the airplane into a steep climb, despite having recently discussed the fact that the plane could not safely ascend due to the unusually high external temperature.

# ? Dec 10, 2011 21:48

Bondematt: Jan 26, 2007; Not too stupid

Tsuru posted:

The airplane initially thought it was overspeeding, so the flight directors commanded a nose-up attitude, which the pilots followed. The crew pulling back on the sticks caused the horizontal stabilizer to autotrim fully up (+14deg if I recall correctly). After this point simply letting go would not have saved them, recovery would have required the crew to push the nose hard down. Don't forget the aircraft also had a very rearwards CG for slightly lower fuel burn in cruise, at 28-29%.

I'm not even sure if at any point they realized their THS was trimmed all the way up.

The plane knew it was in a stall, I haven't seen it say anything about overspeeding. With the pitots blocked it would still be showing last speed(immediate blockage of drain/ram) or no speed(ram blocked) until they changed altitude/unblocked the pitots, assuming they fail the same as a standard pitot.

Was the CG outside of set limits? Cause otherwise it is still dynamically stable, just less so, the point of a CG limit. Of course a full trim will negate the hell out of this.

Never heard about the autotrim being connected to stick input, that is a dumb system at best and Airbus deserves even more flak for that. You should be able to stop what you are doing, and the airplane should recover to neutral (manual, previous or a standard trim)input. Having it fully deflected once the pilots release pressure is just asking for a stall to occur.

Alpine Mustache posted:

Is there something about the Airbus FCS that makes pulling back on the stick during a stall the correct thing to do?

Pulling back on the stick at full throttle is a function of relying on the (now disabled)FCS, it will not let you stall that plane unless it is in "alternative law".

Bondematt fucked around with this message at 22:27 on Dec 10, 2011

# ? Dec 10, 2011 22:20

bloops: Dec 31, 2010; Thanks Ape Pussy!

Bondematt posted:

The plane knew it was in a stall, I haven't seen it say anything about overspeeding. With the pitots blocked it would still be showing last speed(immediate blockage of drain/ram) or no speed(ram blocked) until they changed altitude/unblocked the pitots, assuming they fail the same as a standard pitot.

Was the CG outside of set limits? Cause otherwise it is still dynamically stable, just less so, the point of a CG limit. Of course a full trim will negate the hell out of this.

Never heard about the autotrim being connected to stick input, that is a dumb system at best and Airbus deserves even more flak for that. You should be able to stop what you are doing, and the airplane should recover to neutral (manual, previous or a standard trim)input. Having it fully deflected once the pilots release pressure is just asking for a stall to occur.

Pulling back on the stick at full throttle is a function of relying on the (now disabled)FCS, it will not let you stall that plane unless it is in "alternative law".

Has the investigation or anything else pointed to improper fuel management? If the CG was correct during take off I can't see how it would go bad in-flight outside of total failure to follow procedures.

# ? Dec 10, 2011 22:30

Bondematt: Jan 26, 2007; Not too stupid

HeyEng posted:

Has the investigation or anything else pointed to improper fuel management? If the CG was correct during take off I can't see how it would go bad in-flight outside of total failure to follow procedures.

It would have to be done before takeoff, and from what I've seen they were inside the CG "Envelope". You would never fly a commercial plane outside this.

# ? Dec 10, 2011 22:41

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# ? May 22, 2024 18:49

bloops: Dec 31, 2010; Thanks Ape Pussy!

Bondematt posted:

It would have to be done before takeoff, and from what I've seen they were inside the CG "Envelope". You would never fly a commercial plane outside this.

You wouldn't fly any plane outside of those limitations. Even on the extreme ends of them the a/p can do some drastic trim adjustments to maintain altitude.

Speaking of, anyone know is the Airbus had audible trim movements?

# ? Dec 10, 2011 22:46

The Something Awful Forums > Discussion > Automotive Insanity > Aeronautical Insanity: switching to secondary tolerances

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