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Old August 13th, 2010, 07:49 AM   #1881
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Old August 13th, 2010, 01:20 PM   #1882
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Quote:
Originally Posted by future.architect View Post
So you want the pilot to be able to perform a manoeuvre that will snap the wings off?
No, I want the pilot to be able to perform a maneuver that may result in the plane rolling outside its limits/stalling etc, if that maneuver is necessary to prevent the aircraft from colliding with another/hitting a mountain. The Scarebus will allow the pilot to fly at optimum climb/speed, but won't let the pilot fly the plane to allow it to perform such a maneuver. I also want the guys at row 0 to be be in their seats when it counts - and the yoke gives them a lot better chance of that in the event of cockpit depressurization. The Scarebus sidestick also allows no feedback to the pilot, which a Boeing pilot can get in complete darkness and with complete instrument failure just by placing a pinky on the yoke.

Read and learn.

http://forums.jetphotos.net/showthre...657#post527657

Quote:
..Enough for mechanic controls. Then came hydraulics, or better servo-hydraulics.

In servo-hydraulic systems the yoke moves a servo-valve which proportionally controls the displacement in the hydraulic piston that moves the elevator. The problem here is that moving a servo-valve doesn't require any force and any force applied to the elevator doesn't transmit to the servo-valve and hence to the yoke. Bye-bye feedback.

This is very dangerous, because the pilot could for example displace the yoke enough to apply a lot of Gs and realize only when the plane (and the pilot itself) is already under those Gs, or when the plane breaks under those excessive Gs.

This problem is so serious, and the mechanical system gave such a good feedback, that the airplanes manufacturers, all of them (including Airbus in the early models), decided to design something that they called "artificial feel" and that would be the equivalent of the "force feedback" in modern PC joystics and steering-wheels. And they designed the artificial feel so that the forces on the yoke were proportional to the displacement and to the speed squared! Not by chance that's exactly the same than the mechanical controls.

Then came fly-by-wire.

Fly-by-wire means that the control that the pilot manipulates, regardless of what it looks like, sends digital signals to a computer which then send orders to a hydraulic system to move the elevator. The "dictionary" in the flight computer that translates the the pilot's input into commands to move the elevator is called "flight control law", or control law for short. And here is where manufacturers start to diverge.

The Boeing 777 is fly-by-wire. But the control law is simple: The computer will command the elevator to move proportionally to the displacement of the yoke, just like in the mechanical or hydraulic systems. Also like in mechanical and hydraulic systems, the force needed to displace the yoke that much will be proportional to the displacement and the speed squared, of course again with the help of an "artificial feel" system.

Airbus followed a different philosophy. They decided to take advantage of the power of computers and the flexibility of software programs to create some advanced features.

To begin with, they went for a joystick type of control instead of a yoke. In my opinion, that's the most irrelevant difference (unless there are some issues with the range of motion available).

Then, they got rid of the "artificial feel" system. The joystick is simply a spring-loaded self centering joystick.

Now, with a small control that has no mechanical linkage or hydraulic servo-valves and doesn't even has a force feedback system, the whole device got small enough to be placed virtually anywhere. So they put it at the side thus creating the side-stick. That location has several advantages: It gives the pilot an easier access too and egress from his seat, it lets the pilot hold a chart, a laptop or a tray of food on his lap, it lets the non-flying pilot to cross his legs, and it doesn't obstruct the view to any portion of the instrument panel.

Because the spring-loading and lack of artificial feel, now force and displacement of the joystick are always proportional one to the other. That means that force and displacement now feed back the same piece information, instead of three different pieces of information as the other cases (including the fly-by-wire B-777). Now which piece of information would that be will depend on the design of control law.

Airbus decided not to keep the proportionality between the joystick displacement and the elevator displacement, as had been the case up to then. Instead, they decided that the computer will move the elevator as needed to achieve a G load proportional to the joystick displacement. That means that the same joystick displacement will produce different elevator displacements in function of things such as speed, aircraft weight, and bank angle.

So now the Gs are proportional to the joystick displacement and to the force applied to the joystick. So now both joystick force and joystick displacement are two different feedback for Gs. The feedback for angle of attack and the feedback for speed are gone.

So to prevent that the pilot inadvertently stalls or overspeed the plane, they programmed restrictions in the control law. If the pilot pulls up to command a G load that, at the current speed, would make the airplane stall, it will not comply and will command a pull up just before the stall. If the pilot pushed down into a dive or advances the throttles in a way that would cause an overspeed, the computer won't comply and will pull up to reduce speed before an overspeed happens.

Despite being there two different feedback for Gs (joystick displacement and joystick force), perhaps because the range of displacement is small and the control forces are low they added also a restriction to the Gs. The computer won't command a pull up past the design max Gs despite of how hard the pilot pulls up trying to do so.

With the pilot pulling up hard to avoid a mountain, the computer will fly into the mountain rather than letting the plane break-up due to overstress or stall.

That restricts the pilot authority, but in many cases can be good.

For example, if the pilot finds himself flying into a mountain he can simply apply full power and pull up to the stops without worrying about stalling or breaking the plane. The computer will pull up as much as it can be done without that happening. If that doesn't save the day, nothing will. In any of other systems, the pilot has to "fine tune" his pull-up to achieve that optimum performance. If he just scares and pulls-up hard he can stall and crash in a situation where a max performance escape maneuver might have saved the day. It's like the ABS in your car. It won't let you brake so hard to lock the wheels.

Another important advantage of this philosophy is standardization of the handling characteristics: Moving the side-stick one inch back always requires 0.5 pounds of force and always produce a 1.2Gs pull-up regardless of whether the plane is going fast or slow, is heavy or light, has the center of gravity on the forward or aft limit, or it is a small A 319 or a huge A 380. (the numbers there are not real, I just made them up for the example). That simplifies training and transition between types a lot, and hence saves money to the airlines.

Another difference is that the side-stick is out of the field of view, specially the other pilot's sidestick, and the side-stick are not linked one to the other so when one pilot moves his joystick the other joystick just stays still. That removes the visual feedback for the non-flying pilot to know what flight control inputs the flying pilot is commanding.

Finally, another difference between the Boeing philosophy and the airbus philosophy is how the automation (autopilot and autothrust) controls the systems.

In the Boeing philosophy, the autopilot and autothrottles move the yoke and the throttles like the human pilot would, and then the yoke and throttles transmit the commands in the same way as if it was the pilot who had moved them. This gives the pilot the visual feedback of what the autopilot is doing. The human pilot actually sees the yoke move back when the autopilot pulls-up, and the throttles move forward when the autothrottle adds power.

In the Airbus philosophy the autopilot and autothrust actuate directly on the systems bypassing the yoke and throttle levers. The autopilot tells the flight control computer to pull up, the side-stick doesn't move. The autothrust tells the FADEC to increase power, the throttle levers don't move. So here again, a visual feedback is removed.

It is important to note that this difference have nothing to do with intrinsic characteristics of the side-stick or the fly-by-wire concepts.

The Cirrus SR-20 is a general aviation piston single that is flown using a side-stick, but it's not fly-by-wire. That side-stick is mechanically linked to the elevator, so it shares all the feed-back characteristics of the mechanical control systems. The Boeing 777 is fly-by-wire and uses a yoke that emulates a mechanical control system. They could have chosen to use a side-stick and still emulate a mechanical control system.

Most Airbus use a sidestick with no force feedback and that doesn't move when the other pilot or the autopilot make control inputs. They could have kept those concepts and the same control laws with a yoke instead of a side-stick.

So whoever at Boeing wrote that, he was very careful to word the sentence as to be correct: "Existing commercial side sticks offer no visual or tactile cues to the pilot and must have restrictive performance limits." "Existing commercial side sticks" basically means "Airbus side-sticks". And yes, Airbus sidestick, coupled with Airbus flight laws and the other design features mentioned, offer no visual an little tactile cues to the pilot and have restrictive performance limits. Still, a yoke could be like that too, and a side stick doesn't need to be like that. Those are not intrinsic characteristics, but design decisions. And of course, that doesn't mean that "existing sidestick" are worse than "existing yokes". Neither the contrary.
I prefer the pilot authority over the lack of pilot authority.
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Old August 13th, 2010, 03:35 PM   #1883
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Quote:
Originally Posted by archnyer View Post
No, I want the pilot to be able to perform a maneuver that may result in the plane rolling outside its limits/stalling etc,
In straight words, you want the pilot to be able to break the plane or stall it.

Quote:
Originally Posted by archnyer View Post
if that maneuver is necessary to prevent the aircraft from colliding with another/hitting a mountain. The Scarebus will allow the pilot to fly at optimum climb/speed, but won't let the pilot fly the plane to allow it to perform such a maneuver.
So you pull up hard and the plane stalls...does that get you out of the way of the mountain? don't think so.

Stall necessitates immediate action and requires you to point your nose down to generate lift...not a nice thing given you were trying to escape a mountain in the first place.

Quote:
Originally Posted by archnyer View Post
I also want the guys at row 0 to be be in their seats when it counts - and the yoke gives them a lot better chance of that in the event of cockpit depressurization. The Scarebus sidestick also allows no feedback to the pilot, which a Boeing pilot can get in complete darkness and with complete instrument failure just by placing a pinky on the yoke.

Read and learn.

http://forums.jetphotos.net/showthre...657#post527657

I prefer the pilot authority over the lack of pilot authority.
Oh, not this shyt again...you never answered my question...why do fighter pilots remain in their seats and do all those extreme maneuvers with a joystick not a yoke?

I suggest you demand all fighter jets, including those made by their highness Boeing, be refitted with yokes. Don't thing the fighter pilots will like you for that though.

Ever heard of seat belts? and shoulder straps? those were designed to keep you in your seat and not a yoke.

And just to add to your ridiculous idea of yoke keeping you in your seat in case of depressurization I suggest you take a look at British Airways flight 5390. The windscreen window blew away and the captain was sucked out but his feet jammed and the steward had to grab him from going completely out.

Thanks to that yoke, his whole body was pressing against it which made life difficult for the co-pilot (first office) and also disengaged the auto-pilot. The captain was hanging half-outside the plane pinned to the fuselage. Don't think he could have controlled anything "when it mattered".

I'm not sure you actually read (and understood) the highlighted part of your quote but that is actually going against you. Let the pilots decide what they want to fly and let the safety of the planes tell which one is more safe.
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Old August 13th, 2010, 03:49 PM   #1884
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Quote:
Originally Posted by archnyer View Post
No, I want the pilot to be able to perform a maneuver that may result in the plane rolling outside its limits/stalling etc, if that maneuver is necessary to prevent the aircraft from colliding with another/hitting a mountain. The Scarebus will allow the pilot to fly at optimum climb/speed, but won't let the pilot fly the plane to allow it to perform such a maneuver. I also want the guys at row 0 to be be in their seats when it counts - and the yoke gives them a lot better chance of that in the event of cockpit depressurization. The Scarebus sidestick also allows no feedback to the pilot, which a Boeing pilot can get in complete darkness and with complete instrument failure just by placing a pinky on the yoke.

Read and learn.

http://forums.jetphotos.net/showthre...657#post527657



I prefer the pilot authority over the lack of pilot authority.

That posting you quoted is full of halft truths, but let me just answer to your own statements, because I simply just don't have the time now to take the quoted text apart one by one.

You wrote:
"No, I want the pilot to be able to perform a maneuver that may result in the plane rolling outside its limits/stalling etc, if that maneuver is necessary to prevent the aircraft from colliding with another/hitting a mountain."

There is allready a flaw in your logic of thinking right at the start.
If a plane is about to nearly crash into a mountain, then the one and only reasonable and logical aim has to be flying a maneuver which allows to turn the aircraft away from the obstacle to prevent collision and that usually means flying as close as possible to the aircrafts limits.
You're now saying that you'd like a pilot to be able to fly a maneuver beyond the aircrafts aerodynamical or structural limits, in case such is necessary to prevent a collision.
Exactly this is where the flaw in your logic is.
Such a maneuver beyond the aircrafts limits simply just won't ever be neccessary !
A maneuver within the planes limits is not only much safer but also far more effective.

If you're trying to climb to fly over a mountain for example, the situation is pretty simple. Within the aircrafts aerodynamic limits there is a maneuver which allows a maximum climbrate. If you pull up the aicraft any further you will end up in a stall and the aircraft will then not only slow down and climb far less or even drop, but It may also (especially if only one of the two wings stalls) roll to one side and turn to one side around it's vertical axis since the stalled wing generates has a higher drag backwards, a higher air resistance.

At very high speeds a brutal fighter aircraft type of maneuver would damage the aircrafts structural integrity and thus lead to a disaster not any better than crashing into an obstacle. So the argument the reason why you're bringing that a pilot should be able to force a plane to fly a maneuver beyond it's limits simply doesn't apply because there are no such situations, they simply just don't ever occur. Its a simmilarly intelligent argument as not wearing a seatbelt may be safer because there are accidents where you don't want to end up inside a crushed car.
These type of situations where such nonesense would be beneficial never or hardly ever occur at all. They're a fairytale kind of argument, urban myths.

So all your argument is about when looking at it logically is that you'd like a pilot to chose which way of crashing, which of the possible disaster would be the "better" one.
The price for allowing a pilot this kind of decision is at the sime time allowing the pilot to make a mistakes while trying to fly an optimum maneuver at the very edge of the planes limits. Allowing pilots to accidentally stall a plane when they're trying not to. But these kind of situations where pilots make mistakes trying to climb with a maximum climbrate happen quite regularly and not rarely at all.
So you're basically argueing that you would in fact prefer numerous pilots to be able to make mistakes when trying to avoid an avoidable collision and cause accidents which are avoidable with airbuses safety systems, just for the theoretical (or better: "imaginary") benefit of a pilot being able to chose in which way he wants to wreck the aircraft in a situation when a disaster is inevidable, so he can take a guess which of all possible deaths may be the least painful one for him and the passengers.

But with such a safety system on the other hand a pilot can just pull up as ar as he wants and the plane does all the rest by itself. It reacts in milliseconds to any kind of turbulences in the air preventing a stall, it also flies right at the very edge of the aircrafts aerodynamic limits with the maximum climb rate which a pilot wouldn't even be quite able to find as precisely as the aircrafts computers systems can. So these type of systems can allow a pilot to fly a bit closer to the aicrafts limits than he could ever do without.
These benefits outweigh your suspected or believed benefits of pilots control by far. The only problem is, that one just needs get oneself comfortable with the idea of trusting these kind of systems.

Just like with traffic on our roads where people keep make driving errors and cause accidents, in modern airtraffic the pilots mistakes sadly are indeed a very major safety problem which can be minimized with electronic systems. But to minimize pilots errors one naturally must take away some control over the aircrafts from them. And that is naturally exactly not allowing pilots to fly maneuvers which inevitably lead to a disaster.
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Old August 14th, 2010, 01:06 AM   #1885
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Jesus christ! Do you read this stuff before you post it?

Quote:
With the pilot pulling up hard to avoid a mountain, the computer will fly into the mountain rather than letting the plane break-up due to overstress or stall.
Are you trying to say that crashing into the mountain 'because the computer wont let you' is worse than crashing into the mountain because the wings have snapped off because you tried to do something the plane wasnt built to handle? They are both prety bad outcomes.

Quote:
That restricts the pilot authority, but in many cases can be good.

For example, if the pilot finds himself flying into a mountain he can simply apply full power and pull up to the stops without worrying about stalling or breaking the plane. The computer will pull up as much as it can be done without that happening. If that doesn't save the day, nothing will. In any of other systems, the pilot has to "fine tune" his pull-up to achieve that optimum performance. If he just scares and pulls-up hard he can stall and crash
Quote:
Originally Posted by archnyer View Post
No, I want the pilot to be able to perform a maneuver that may result in the plane rolling outside its limits/stalling etc, if that maneuver is necessary to prevent the aircraft from colliding with another/hitting a mountain. The ScareAirbus will allow the pilot to fly at optimum climb/speed, but won't let the pilot fly the plane to allow it to perform such a maneuver.
Then I suggest that you don't fly on a Boeing 787 or 777 either since they both use a flight protection system. Also, the 787 and 777 don't make it easy to override the protection. In most cases both pilots will have to use excesive force to get the plane to do what they want, such as snap the wings off...

In other words, Its not easy to override a Boeing. But its not impossible on an airbus either.

Quote:
I also want the guys at row 0 to be be in their seats when it counts - and the yoke gives them a lot better chance of that in the event of cockpit depressurization.
If the depressurisation is enougth to suck the pilot out of his seat, its probably enough to pull the yoke off as well.

Quote:
The ScareAirbus sidestick also allows no feedback to the pilot, which a Boeing pilot can get in complete darkness and with complete instrument failure just by placing a pinky on the yoke.
Airbus planes just as easy to fly in the dark. Feedback is not needed when you have protection because you cannot make the plane do anything that would damage it. Hence the reason why airbus decided to do away with it

Quote:
I prefer the pilot authority over the lack of pilot authority.
[/QUOTE]

As I said before, the 787 and the 777 both use fly by wire and flight protection as well, the same as airbus.

watch this


Last edited by future.architect; August 14th, 2010 at 01:28 AM.
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Old August 14th, 2010, 02:33 AM   #1886
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Manchester Airport prepares for A380 flight

Manchester Airport said that it expects a large number of people to turn up to witness the first time the super jumbo A380 touches down at the hub.

Emirates is to begin operating services to Dubai on the double-decker aircraft from Manchester Airport, which is the first regional hub to serve the jet, on September 1st.

Facilities on board the A380 include an in-flight entertainment system with over 1,200 channels, 14 private suites and electrically controlled mini-bars in first class.

The Runway Visitor Park at Manchester Airport is opening at 08:00 BST on the day to accommodate the expected crowds that build up before the plane touches down at 12.25 BST.

Andrew Cornish, managing director of Manchester Airport, said: "This is a once in a lifetime opportunity to see the A380 arrive and I put it on a par with the last flight of Concorde to Manchester."

Visitors who arrive at the park on foot or public transport will be able to enter for free but cars will only be allowed to enter with a pre-booked ticket priced at £12.
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Old August 14th, 2010, 02:33 AM   #1887
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Qantas A380 forced down in the Pacific

A QANTAS Airbus A380 landed in the French Pacific territory of New Caledonia for the first time yesterday after the superjumbo was diverted from Sydney due to bad weather, officials said.

"It's a first for us,'' William Grillon, deputy head of operations at the Noumea airport, said.

"But we were ready to receive this large aircraft, as the airport in New Caledonia is a diversion airport for the region's airspace,'' he said.

The Qantas plane with 375 passengers and 26 crew aboard was heading to Sydney from Los Angeles, but poor weather forecast for Australia's entire east coast forced it to divert yesterday morning.

It had been due to arrive in Sydney at 6.30am AEST yesterday, but the Sydney Airport website says the flight was estimated to arrive 13 hours later, at 7.30pm.

"QF12 diverted to Noumea this morning for extra fuel due to heavy fog forecast for Sydney ... and the eastern seaboard,'' a Qantas spokeswoman said.

"Safety is our first priority, hence the captain made the decision to divert to Noumea for additional fuel.''

The crew had exceeded their maximum allowed flying time, and so the passengers were awaiting a Qantas Boeing 747 to take them onto Sydney, Grillon said.

"The flight will now operate from Noumea to Sydney this afternoon arriving in Sydney at approximately 6.15pm,'' Qantas said.
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Old August 14th, 2010, 02:34 AM   #1888
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Manchester Airport prepares for A380 flight

Manchester Airport said that it expects a large number of people to turn up to witness the first time the super jumbo A380 touches down at the hub.

Emirates is to begin operating services to Dubai on the double-decker aircraft from Manchester Airport, which is the first regional hub to serve the jet, on September 1st.

Facilities on board the A380 include an in-flight entertainment system with over 1,200 channels, 14 private suites and electrically controlled mini-bars in first class.

The Runway Visitor Park at Manchester Airport is opening at 08:00 BST on the day to accommodate the expected crowds that build up before the plane touches down at 12.25 BST.

Andrew Cornish, managing director of Manchester Airport, said: "This is a once in a lifetime opportunity to see the A380 arrive and I put it on a par with the last flight of Concorde to Manchester."

Visitors who arrive at the park on foot or public transport will be able to enter for free but cars will only be allowed to enter with a pre-booked ticket priced at £12.
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Old August 14th, 2010, 02:47 PM   #1889
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It's always great to see enthusiasts here on the forum. And also it's always good to see some Scarebus fanboys too.

Fighter pilot stick? That's a whole different beast than a sidestick in an Airbus. It serves a purpose - high end maneuvers - and it's right between the pilots legs. In WWII, planes with yokes were actually preferred by pilots, like the P-38. It allowed better control to torso reference and stability. And no, a Boeing yoke connected with cables will not tear out, but a pilot sitting unstrapped will.

Put simply, the sidestick is not something I would want to be using when the aircraft is out of control (no reference, feedback, hard to use at side of body) or where there is massive turbulence (yoke between legs far easier to control).

The biggest point is that a Boeing yoke allows reference and feedback.

But don't let that sway you, because you aren't interested in having pilots fly the plane.

Forget the mountain for a minute, think about collisions with another aircraft or an obstacle at the end of the runway after takeoff where they can't gain alititude quickly enough - the pilots sometimes need to be able to fly the plane.

And just like a mountain or obstacle, that means trading something for something. Like the fact that one may stall the aircraft and be required to put nose down after the mountain/obstacle/other aircraft is cleared. Something you cannot do if you have already crashed into it because in the Scarebus, it simply will not let you "fly the plane" and pull a maneuver like this. That's Scarey!

You need to read the quote again and answer it directly. Because it's probably written by a pilot, shows some of the good aspects of Scarebus like being able to climb optimally with little effort, but more importantly, it's 100% correct.

Quote:
Airbus followed a different philosophy. They decided to take advantage of the power of computers and the flexibility of software programs to create some advanced features.

To begin with, they went for a joystick type of control instead of a yoke. In my opinion, that's the most irrelevant difference (unless there are some issues with the range of motion available).

Then, they got rid of the "artificial feel" system. The joystick is simply a spring-loaded self centering joystick.

Now, with a small control that has no mechanical linkage or hydraulic servo-valves and doesn't even has a force feedback system, the whole device got small enough to be placed virtually anywhere. So they put it at the side thus creating the side-stick. That location has several advantages: It gives the pilot an easier access too and egress from his seat, it lets the pilot hold a chart, a laptop or a tray of food on his lap, it lets the non-flying pilot to cross his legs, and it doesn't obstruct the view to any portion of the instrument panel.

Because the spring-loading and lack of artificial feel, now force and displacement of the joystick are always proportional one to the other. That means that force and displacement now feed back the same piece information, instead of three different pieces of information as the other cases (including the fly-by-wire B-777). Now which piece of information would that be will depend on the design of control law.

Airbus decided not to keep the proportionality between the joystick displacement and the elevator displacement, as had been the case up to then. Instead, they decided that the computer will move the elevator as needed to achieve a G load proportional to the joystick displacement. That means that the same joystick displacement will produce different elevator displacements in function of things such as speed, aircraft weight, and bank angle.

So now the Gs are proportional to the joystick displacement and to the force applied to the joystick. So now both joystick force and joystick displacement are two different feedback for Gs. The feedback for angle of attack and the feedback for speed are gone.

So to prevent that the pilot inadvertently stalls or overspeed the plane, they programmed restrictions in the control law. If the pilot pulls up to command a G load that, at the current speed, would make the airplane stall, it will not comply and will command a pull up just before the stall. If the pilot pushed down into a dive or advances the throttles in a way that would cause an overspeed, the computer won't comply and will pull up to reduce speed before an overspeed happens.

Despite being there two different feedback for Gs (joystick displacement and joystick force), perhaps because the range of displacement is small and the control forces are low they added also a restriction to the Gs. The computer won't command a pull up past the design max Gs despite of how hard the pilot pulls up trying to do so.

With the pilot pulling up hard to avoid a mountain, the computer will fly into the mountain rather than letting the plane break-up due to overstress or stall.

That restricts the pilot authority...
I see the fog in Sydney was too much for the Scarebus computers. They couldn't land the plane.

It doesn't matter, because I would prefer a plane a pilot can actually control - at all times - not just when the computers says so.

And the 777 and 787 have the same as Scarebus? No they don't - they actually have a lot of hard control cabling built in that the Scarebus does not.

Tell me guys, what happens on these Scarebuses in the event of electrical failure. FBW only (a la Scarebus) would really suck.
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Old August 14th, 2010, 03:35 PM   #1890
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Quote:
Originally Posted by archnyer View Post
It's always great to see enthusiasts here on the forum. And also it's always good to see some Scarebus fanboys too.

Fighter pilot stick? That's a whole different beast than a sidestick in an Airbus. It serves a purpose - high end maneuvers - and it's right between the pilots legs. In WWII, planes with yokes were actually preferred by pilots, like the P-38. It allowed better control to torso reference and stability. And no, a Boeing yoke connected with cables will not tear out, but a pilot sitting unstrapped will.

Put simply, the sidestick is not something I would want to be using when the aircraft is out of control (no reference, feedback, hard to use at side of body) or where there is massive turbulence (yoke between legs far easier to control).

The biggest point is that a Boeing yoke allows reference and feedback.

But don't let that sway you, because you aren't interested in having pilots fly the plane.

Forget the mountain for a minute, think about collisions with another aircraft or an obstacle at the end of the runway after takeoff where they can't gain alititude quickly enough - the pilots sometimes need to be able to fly the plane.
And just like a mountain or obstacle, that means trading something for something. Like the fact that one may stall the aircraft and be required to put nose down after the mountain/obstacle/other aircraft is cleared. Something you cannot do if you have already crashed into it because in the Scarebus, it simply will not let you "fly the plane" and pull a maneuver like this. That's Scarey!

You need to read the quote again and answer it directly. Because it's probably written by a pilot, shows some of the good aspects of Scarebus like being able to climb optimally with little effort, but more importantly, it's 100% correct.



I see the fog in Sydney was too much for the Scarebus computers. They couldn't land the plane.

It doesn't matter, because I would prefer a plane a pilot can actually control - at all times - not just when the computers says so.

And the 777 and 787 have the same as Scarebus? No they don't - they actually have a lot of hard control cabling built in that the Scarebus does not.

Tell me guys, what happens on these Scarebuses in the event of electrical failure. FBW only (a la Scarebus) would really suck.

Well I wrote it before and I'm gonna write it again.
These szenarios you construct here hardly ever occur at all.

Now argument Nr. 1. The yoke:
DO you seriously believe in the event of a cockpit depressurisation a pilot would hang on a yoke and not be sucked out?
Do you seriously believe an incident like that is anywhere near likely to happen at all?
Do you believe a pilot hanging on a yoke could still steer the plane? Do you believe a copilot could steer a plane with someone next to him hanging on the yoke constantly giving the aircraft steeringcommands into whatever direction he's being pulled?

Nr2 stalling an aircraft to avoide an obstacle:
I see that You obviously have no real clue about aerodynamics at all.
Right the instant a wing stalls the lift decreases and the airrestistance increases. you might believe that an aircraft would climb more than the maximum climbrate for a short moment when the nose is pulled up when it stalls, but that is simply not the case. There is no short extra kick upwards when you stall a plane pulling the nose up too high there simply isn't. That's due to the physics, the laws of fluidmechanics, no matter if you believe anything different or if a pilot wishes for a short extra kick up. What happens when you pull a plane up more and more, ist that you increase the climbrate gradually to the point of the maximum climb rate, then suddenly with very little warning the wings stall and the uplift decrease dramatically. That's because the Bernoulli effect doesnt occur anymore when there is a turbulent airflow on the topside of a wing. You suddenly loose the uplift due to that effect when the wing stalls and the airesistance increases due to the turbulences so the plane slows down. In the process of stalling a plane there simply is no moment where the uplift increases suddenly, there is no extra boost upwards higher than the maximum climbrate when the wings are not stalled, the uplift allways only decreases.
So stalling a plane trying to avoid an object never provides any kind of advantage over not stalling it, never ever!
Study some aerodynamics and you will learn that.

Argument Nr3 - electrical failure:
In case of an complete and full electrical and hydraulic failure pretty much the same thing happens in an Airbus as in a boeing - the plane becomes unflyable. Modern aircraft are not flyable just with human muscles without any form of servohydraulic- or electric servo- support. A human simply isn't strong enough to move the large rudders and flaps of those aircrafts with pure musclepower.
Those planes are not WW2 bombers which can be steered with musclepower, they are far bigger, heavier and faster. So Boeing and Airbus basically have the same problem. If these vital systems which are necessary to move the rudders and flaps completely fail, there is no way a pilot can steer the plane anymore.
But luckily these systems are redundant and don't fail very often, especially not all at once. This kind of total failure happens far, far, far less often than pilots making a mistake. I don't even know if such a kind of total faliure where a plane becomes unsteerable ever happened at all in modern aviation.
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Old August 14th, 2010, 03:43 PM   #1891
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Old August 14th, 2010, 04:11 PM   #1892
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Quote:
Originally Posted by Alemanniafan View Post
So stalling a plane trying to avoid an object never provides any kind of advantage over not stalling it, never ever!
Study some aerodynamics and you will learn that.
Except when a pilot needs to make a snap climb, turn or roll to avoid one or more parts of the plane from hitting another object. He/she will trade airspeed and the risk of losing control subsequently for being able to avoid hitting that object, be it moutain tip, hill, trees at the end of the runway, or another aircraft (more unlikely). Scarbus doesnt let you perform that maneuver.

Re the fbw, you are partially right. The Airbuses do have the ability to steer 2 control surfaces only by hydraulics and its a PITA but able to be done. But the Boeings have a lot more hydraulic operability.

Re the yoke, Im talking about a situation when the pilots are in their seats but not strapped. The yoke gives them something extra. But the real advantage of the yoke is as I stated, when there is turbulence, when there is a need for torso to body reference, and when you need feedback (the sidesticks offer none of these).
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Old August 14th, 2010, 04:16 PM   #1893
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OH please...your whole argument is "I like", "I prefer"...but that's just you not the entire pilot community. You may prefer that, its your own choice but doesn't mean everyone likes it.

I can only laugh at your yoke arguments. I have even given you an example about it. Seat belt tearing and shoulder straps tearing and there is a yoke for you to hang on to...lol. The whole plane would tear up first before those shoulder strap break. And that yoke did the British Airways crew no good. Your arguments are only suiting your imaginations but not the real world.

So you agree fighter pilots do high-end manuevers yet the joystick is just fine for their 'torso reference'. Forget WWII, we have come a long way since then and most if not all fighters use a stick. If that yoke that so much reference as you would like to believe, it would have been there.

Visual feedback is a different thing altogether and can be used on either a stick or a yoke. Pilots are however trained to rely on their instruments as your feelings and senses are going to betray you. Its a common phenomenon called Vertigo and have been identified as a reason of crashes. Another reason why using your 'torso reference' is a very bad idea.

Btw, unlike your quote (probably written by a pilot), that video posted by future.architect IS a boeing 757 commercial pilot.

And stalls do not occur 'after you clear the mountain'. A stall will occur immediately you loose lift. In simpler words, there could be a scenario you (pilot) make a mistake and not clear the mountain while an optimal ascend will let you do it. But if the optimal climb rate is unable to do so, rest assure you too are going to crash it by stalling it.

Boeing 777 and later are FBW ONLY too like airbus. There are NO cables running to the control surfaces but only wires carrying electrical signals. And just for your information (which you seem to need quite a bit) those FBW systems have multiple redundancy. So tell me, how many FBW systems have failed till date? And how many cable+ hydraulic systems have failed?

I am quite happy with a pilot that takes the safety of his passengers more than his ego to be able to fly into a difficult weather condition. Do you want me to start on the number of plane accidents (mostly Boeing btw) in which weather was the primary contributing factor?

As I have said before, I am an aviation enthusiast and I love both Airbus and Boeing (well atleast their later planes). If you want to appreciate aviation and gain knowledge about it, come with an open mind rather than with a pre-judgment and looking for ways to twist facts to suite your belief.

There is no use arguing with someone with pre-conceived notions and prejudices. At the end I ask you one question...what percentages of aircrashes result from pilot error? as compared to design or computer errors?
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Old August 14th, 2010, 04:33 PM   #1894
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You do understand that once the engine stalls due to a snap climb the plane starts to tumble sideways. Although I have never seen this happen to a passenger jet this is the most feared situation for a fighter pilot since the pilot loses all control of the plane.

Isn't most all modern day passenger jets being controlled by "fly by wire"systems?
TO my understanding there are no hydraulic pipes heading towards the cockpit.
There are no feedbacks with this kind of system unless they programed an induced simulation like the ones on game system with force feedback.
Hydraulic response in modern day passenger planes are result of the size of actuators moving the flaps which have nothing to do with how much force you place in the cockpit.

Finally electrical failure?
Are you serious?
All the engines generate electricity with separate relay redundancy, unless all engines fail there is no such thing as complete electrical failure on a plane.
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Old August 14th, 2010, 04:39 PM   #1895
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Quote:
Originally Posted by archnyer View Post
It's always great to see enthusiasts here on the forum. And also it's always good to see some ScareAirbus fanboys too.
Boeing fanboys are the worse kind of fanboys, in my opinion

Quote:
Originally Posted by archnyer View Post
Fighter pilot stick? That's a whole different beast than a sidestick in an Airbus. It serves a purpose - high end maneuvers - and it's right between the pilots legs. In WWII, planes with yokes were actually preferred by pilots, like the P-38. It allowed better control to torso reference and stability. And no, a Boeing yoke connected with cables will not tear out, but a pilot sitting unstrapped will.
You must be insane if you think that holding onto a yoke will stop you getting sucked out of the plane!

Quote:
Originally Posted by archnyer View Post
Put simply, the sidestick is not something I would want to be using when the aircraft is out of control (no reference, feedback, hard to use at side of body) or where there is massive turbulence (yoke between legs far easier to control).
But you are not a pilot, how can you say that. And before you say 'i can find 10 pilots who prefer a yoke' and can find 10 pilots who prefer a sidestick.
If Airbus planes where as difficult to fly as you make out, they would not be flying at all. The FAA and the ESA would have stopped them from putting the system on planes.

Quote:
Originally Posted by archnyer View Post
The biggest point is that a Boeing yoke allows reference and feedback.
But don't let that sway you, because you aren't interested in having pilots fly the plane.
As I have said before, you dont need feedback if you cant overstress the plane anyway. I can see why some pilots may prefer to have it, but its not essential.

Quote:
Originally Posted by archnyer View Post
Forget the mountain for a minute, think about collisions with another aircraft or an obstacle at the end of the runway after takeoff where they can't gain alititude quickly enough - the pilots sometimes need to be able to fly the plane.

And just like a mountain or obstacle, that means trading something for something. Like the fact that one may stall the aircraft and be required to put nose down after the mountain/obstacle/other aircraft is cleared. Something you cannot do if you have already crashed into it because in the Scarebus, it simply will not let you "fly the plane" and pull a maneuver like this. That's Scarey!
The why can't you understand. The airbus flight envolope protection system does not restrict the plane, it protects it. The system only stops you making a manorvre that will cause the plane structural damage, cause it to stall or cause it to loose control. All of those outcomes are realy bad and no pilot will ever want to make a plane ever do anything like that.
In the case of of US 1549 the stall protection saved the day. It allowed the pilot to fly the plane as slow as possible knowing that he could not stall the plane. Im not saying that a 737 in that situation would have a worse outcome, but it certainly would have been much harder for the pilots.

In other words your point is stupid. If you needed to avoid an obsticle at the end of the runway, pulling the nose up as much as possible would stall the plane or snap the wings off so you would come plunging back to earth anyway.

Also have relised that the most famous (worse air crash ever) crash involving two planes on one runway, the teneriffe dissater, involved two boeing 747's. Also remember the singapore airlines crash where the pilot tried to take off on a runway which had contruction equiptment on it killing 83 in the process, also a 747. Boeing did not save the day on these occasions.

I cannot think of one incident where an airbus plane has crashed because the plane did not let them do something. The reason I cannot think of anything is because it has never happend.

Quote:
Originally Posted by archnyer View Post
I see the fog in Sydney was too much for the ScareAirbus computers. They couldn't land the plane.
I do not know what incident you are refering to.

Quote:
Originally Posted by archnyer View Post
It doesn't matter, because I would prefer a plane a pilot can actually control - at all times - not just when the computers says so.
As i said before, the airbus computers do not restrict the plane, they protect it. They only stop the pilot doing something which the plane would not be able to handle safely.

Quote:
Originally Posted by archnyer View Post
And the 777 and 787 have the same as Scarebus? No they don't - they actually have a lot of hard control cabling built in that the ScareAirbus does not.
Actualy, the 787 and the 777 both use airbus like flight protection system, even you cant deny that! Both airbus and boeing both have a manual backup to some (not all) controll surfaces which would be usefull in total electrical failure. (an unlikely scenario)

Quote:
Originally Posted by archnyer View Post
Tell me guys, what happens on these Scarebuses in the event of electrical failure. FBW only (a la ScareAirbus) would really suck.
I can tell you actualy:

Quote:
Airbus use mechanically connected Stab Trim and rudder pedals but as stated above latest models of A330/340 have deleted the mechanical rudder cables. 777 uses mechanical cables for stab trim and one pair of flight spoilers.
Source

So boeing has gone further than airbus and put 1 pair of manual spoilers on the 777? Wow, thats realy going to save the day.

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Old August 14th, 2010, 04:40 PM   #1896
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Old August 14th, 2010, 04:42 PM   #1897
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Old August 14th, 2010, 04:47 PM   #1898
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Old August 14th, 2010, 05:02 PM   #1899
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Quote:
Originally Posted by archnyer View Post
Except when a pilot needs to make a snap climb, turn or roll to avoid one or more parts of the plane from hitting another object. He/she will trade airspeed and the risk of losing control subsequently for being able to avoid hitting that object, be it moutain tip, hill, trees at the end of the runway, or another aircraft (more unlikely). Scarbus doesnt let you perform that maneuver.

Re the fbw, you are partially right. The Airbuses do have the ability to steer 2 control surfaces only by hydraulics and its a PITA but able to be done. But the Boeings have a lot more hydraulic operability.

Re the yoke, Im talking about a situation when the pilots are in their seats but not strapped. The yoke gives them something extra. But the real advantage of the yoke is as I stated, when there is turbulence, when there is a need for torso to body reference, and when you need feedback (the sidesticks offer none of these).
About your snap climb phantasies, I explained why you can't climb faster than the maximum climb rate. Study aerodynamics and you'll see I'm right. Airplanes don't allways do what hollywood movies want to make us believe, other than movies they are bound to the laws of physics, sadly.

About turning and rolling to avoid hitting objects line trees mountain tops or other aicraft:
Turning and rolling are both also possible within the aerodynamic flight envelope, within aerodynamic limits. It's not like an aicraft can only be turned and rolled when its stalled or flying beyond its limits.

All your creatively fantacised argument here is basically about is ripping off one wing in order to have the chance of avoiding to hit an obstacle with the other. That simply doesn't help and situations like these simply don't occur.

All your made up szenarios here so far each and all are not szenarios where a maneuver beyond the aircrafts limits would be beneficial over a maneuver within the aircrafts limits. You have not even constructed a single one szenario that is, as unlikely as they all may be.
But on the other hand in each and every one of your szenarios a pilot making a mistake stalling the aircraft would cause an accident that was avoidable if he didn't (unless a crash is completely unavoidable anyways of course). So in all your szenarios a safety system helping and preventing pilots from stalling a plane accidentally proves very beneficial.
Wether you like it or not even you should plain reasonably be able to understand and see that preventing pilots from stalling an aicraft unintentionally by accident in these dangerous kind of situations would potentially save lives in nearly all of these near crash type of szenarios, because these critical kind of szenarios just don't leave any room for pilots mistakes. Pilots mistake in such critical kind of situations unavoidably always lead into a disaster. So even if there were just the fewest and most improbable imaginary and theoretical kind of situations where a maneuver like you're suggesting could end up being beneficial, the number of situations where a pilots mistake is prevented outweigh these by far. The benefit of preventing pilots from making mistakes outweighs the theoretical and imaginary benefit of full pilots control to force a plane beyond its limits by far. So flying in a plane with a system preventing teh pilot from flying a maneuver beyond the aircrafts limits is safer than flying in one where the pilot can make these mistakes.

Now again about the Yoke and feedback:
Surely feedback is something good and positive. But you're forgetting that it's no actual feedback it's no "real feedback" but just "simulated feedback". So if there is a flaw ind the system that simulates or generates the feedback for the pilot is flawly then this system isn't beneficial and doesn't necessarily improve the overall and effective safety. Plus when flying by wire through turbulences the aircrafts computer systems ract faster than the pilot can. So feedback isn't allways really helpful, efective or necessary simply because the airplane is "flying itself" in these kind of situations which require a faster reaction than the pilot can provide. The plane basically keeps itself straight and stable in these kind of situations, not the pilot.
Feedback in situations where the Pilot is (because of his biology, his reaction time, his signal processing speed...) not the ideal system to react to changes can lead to faulty Pilots reactions and can hardly provide any benefits. Because the planes computers are superior to the pilots abilities in the task of keeping an aicraft flying straight,stable, safe and not rippping the wings off.
An example from modern cars where feedback can cause trouble are antilock brakes. Many unexperienced drivers are afraid to push the braking pedal all the way down when driving a modern car with antilock brakes. and when the brakes start to rattle or vibrate because the antilock system is active they pull the foot from the barkes because they're afraid the car is falling appart.
Of course experienced drivers and well educated drivers don't, but fools who have no clue about driving and the technology behind antilock braking systems regulary make this kind of mistake. So it is an example where in quite a few cases an antilock brake system can lead a fool as a driver to cause an aviodable accident, which they wouldn't have ended up in if they knew better or had a classic brake without such a "scary" antilock braking system.

As we see, feedback to a pilot is not allways necessary or automatically beneficial, even though it of course usually and in most cases shouldn't do any harm and is generally desirable. But as I wrote Boeing aircrafts don't provide real and actual feedback they artificially generate and simulate it. And that is something compeltely different that real and actual feedback is.
Its kinda like plaing a game with a force feedback joystick or a rumblepad just far more sophisticated and realistic, but not much different in its nature.
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Old August 15th, 2010, 01:42 AM   #1900
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...Forget the mountain for a minute, think about collisions with another aircraft or an obstacle at the end of the runway after takeoff where they can't gain alititude quickly enough - the pilots sometimes need to be able to fly the plane...
Some years back a Russian pilot did just that and his plane with dozens of kids on board collided with a DHL cargo plane.

Why? because he did what he thought was best, instead of following the anti-colision system instruction that the computer presented him.

As for the mountain: Why will a plane head toward a mountain, unless a pilot made an error somehow?
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