For you Aviation buffs

[Voodoochild]

http://www.youtube.com/watch?v=nYDba1UsgHc&feature=youtube_gdata_player

Airbus A-319/320/321

[Hmac]

Cool video. Ya sure gotta wiggle the sticks a lot...

[Suwannee Tim]

Cool video. Ya sure gotta wiggle the sticks a lot...

Me too. I noticed that stick action too. I've can't recall seeing that much stick movement. I wonder if this thing is fly by wire?

[An Undocumented Worker]

Me too. I noticed that stick action too. I've can't recall seeing that much stick movement. I wonder if this thing is fly by wire?

Yeah they are fly by wire.

[rjacobs]

If you roll the 'bus into a turn or pitch into a climb or descent and release the stick, it holds the attitude that you put it at. Thats why you see all the stick movement. Theres also not really any feedback from the stick in what kind of loading the control surfaces have on them so its easy to put to much into it and have to correct back a little bit which means a big movement back the other way, not just relaxing pressure a little like in a normal aircraft.

Cool video though. I need to put together something from all the video I have from flying.

[An Undocumented Worker]

If you roll the 'bus into a turn or pitch into a climb or descent and release the stick, it holds the attitude that you put it at. Thats why you see all the stick movement. Theres also not really any feedback from the stick in what kind of loading the control surfaces have on them so its easy to put to much into it and have to correct back a little bit which means a big movement back the other way, not just relaxing pressure a little like in a normal aircraft.

Cool video though. I need to put together something from all the video I have from flying.

I'm not a pilot, but just imagine a car with steering like that. Do not want.
Stuff like that seriously makes me wonder if the engineering team that designed the contol system had any experience what so ever flying/driving a vehicle. Or if they even solicited input from experienced individuals.

[Suwannee Tim]

Come to think of it I have seen video of an aircraft flying off the deck of a carrier and landing and the pilot was doing the same rapid motion of the stick. It was an FA 18 iirc. The pilot, an acquaintance, lost an engine on takeoff on the same cruise. The aircraft carrier has video cameras watching the flight deck from many angles and Cdr. Leinhouts (sic?) made a video of the mishap. The aircraft rapidly rolled, lost altitude then hit the water. Leinhouts jumped out about 1/64 of a second before too late. He got doctored, got drunk, got sober then got back in. Amazing. His BIL was training a newbie who for unexplained reasons decided to activate the ejection system. He was flying along and BOOM!, BOOM! hanging from a parachute. He lost his nerve and never flew again.

[Hmac]

I'm not a pilot, but just imagine a car with steering like that. Do not want.
Stuff like that seriously makes me wonder if the engineering team that designed the contol system had any experience what so ever flying/driving a vehicle. Or if they even solicited input from experienced individuals.

You have to be kidding....

[An Undocumented Worker]

You have to be kidding....

Kidding about what?

Lack of tactile feedback on control inputs is not something I'm a fan of.

[RogerinTPA]

Cool video. Looks like the pilot was over controlling or had an involuntary reflex to over control. You don't need to move it all that much. When I flew Helos in the Army, some guys would constantly move the cyclic, in an almost rhythmic pulse, and didn't notice until I or some else, pointed it out.

[ForTehNguyen]

Kidding about what?

Lack of tactile feedback on control inputs is not something I'm a fan of.

have fun trying to fly a large plane that does not have a drive by wire hydraulic system. B17s had to have both pilots pull on the stick, not to mention the flight control stick extended another 8 foot down into the bombardier room just to get the mechanical leverage to move the planes control surfaces.

[An Undocumented Worker]

have fun trying to fly a large plane that does not have a drive by wire hydraulic system. B17s had to have both pilots pull on the stick, not to mention the flight control stick extended another 8 foot down into the bombardier room just to get the mechanical leverage to move the planes control surfaces.

You can have hydraulic assist and still maintain tactile feedback, Aka how Boeing does it. That method technically is not fly by wire.

Airbus is has no hydraulic link between the control surfaces and the stick. From what I understand they have no feedback on the stick whatsoever.


My particular frame of reference comes from automotive technology, On power steering systems you have either hydraulic or electrical assist today, yet still maintaining a mechanical linkage between the steering wheel and the rack.
There are some companies tinkering with the idea of completely eliminating that mechanical linkage, which in turn either eliminates feedback or requires more complicated systems to add it back in.
Then understanding how cheaply companies try to make parts, it is a recipe for disaster.

I've just seen way too many instances of engineering trying to integrate technology into a system to solve one problem but getting tunnel vision in regards to the compromises that technology makes, thus introducing other problems.

To boil all of that down, quite simply I am hesitant to accept systems where the human interface on a vehicular control device is only requesting a response from a computer.

[CarlosDJackal]

You can have hydraulic assist and still maintain tactile feedback, Aka how Boeing does it. That method technically is not fly by wire...blah-blah-blah

And how many flight hours and flying aircraft have you designed or engineered again?

Hydraulic assist and the type of feedback that you claim would be better than a fly-by-wire system has issues in that:

(a) They generally do not facilitate the type of stability that computerized systems provide and are needed for such large aircraft. This is not a Fighter Plane that is designed to engage in air-to-air or air-to-ground combat.

(b) Control feedback, especially the type provided by Hydraulic Assisted systems, is not conducive to the extended flying times these types of aircraft are designed to perform. The fly-by-wire system eliminates the type of vibration that is ever present in hydraulic, cable or hydraulic assisted systems have.

Now try to guess how many hours I have flying aircraft that were equipped with hydraulic-assisted controls under VFR and IFR as well as NOE conditions? HINT: I still hold an Commercial Instrument license and the number is more than 1. :rolleyes:

[Hmac]

Kidding about what?

Lack of tactile feedback on control inputs is not something I'm a fan of.

Kidding about whether or not Airbus Industries' "engineering team that designed the contol system had any experience what so ever flying/driving a vehicle. Or if they even solicited input from experienced individuals."

Airbus is arguably the word's leader in airliner production and sales, outpacing Boeing in both orders and deliveries for the last 5 years. I'm pretty confident that in developing their fly-by-wire flight control sytem, they probably sought the opinion of a pilot or two.

[An Undocumented Worker]

And how many flight hours and flying aircraft have you designed or engineered again?

Hydraulic assist and the type of feedback that you claim would be better than a fly-by-wire system has issues in that:

(a) They generally do not facilitate the type of stability that computerized systems provide and are needed for such large aircraft. This is not a Fighter Plane that is designed to engage in air-to-air or air-to-ground combat.

(b) Control feedback, especially the type provided by Hydraulic Assisted systems, is not conducive to the extended flying times these types of aircraft are designed to perform. The fly-by-wire system eliminates the type of vibration that is ever present in hydraulic, cable or hydraulic assisted systems have.

Now try to guess how many hours I have flying aircraft that were equipped with hydraulic-assisted controls under VFR and IFR as well as NOE conditions? HINT: I still hold an Commercial Instrument license and the number is more than 1. :rolleyes:


Kidding about whether or not Airbus Industries' "engineering team that designed the contol system had any experience what so ever flying/driving a vehicle. Or if they even solicited input from experienced individuals."

Airbus is arguably the word's leader in airliner production and sales, outpacing Boeing in both orders and deliveries for the last 5 years. I'm pretty confident that in developing their fly-by-wire flight control sytem, they probably sought the opinion of a pilot or two.

What can I say, I don't trust computers that have the ability to completely overide a human's input on a device that is transporting them. Especially when the computers decisions are based upon sensors manufactured by humans.

And to be perfectly honest, Hmac I would be more likely to trust your ability to fly a plane given the massive amount of training you most likely have flying them, than I would trusting an engineering team that was scattered across many countries that designed in the ability of the plane to competely ignore the pilots commands. Especially given conditions where the computer could be recieving erroneous information.

As I stated my background comes from the automotive field which is starting to use similar technologies, and I have seen cases where computers make poor decisions based off of faulty data.


The event that highlights my concern about such control systems is Air France Flight 447


While I would only ever be a mere passenger on an airliner, I trust the ability of a well trained human to make appropriate decisions under stress and contradictory data, than I do a computer.

I mean no disrespect to aviation professionals, I personally will try to avoid taking a flight on an Airbus whether my opinion is valid, or completely off base.

If it is offbase, please by all means educate me.

[ForTehNguyen]

the military depends on planes that are designed to be inherently unstable for maximum maneuverability. It becomes controllable by a human with that computer control system. These arent to be trusted? All flight control systems have the ability for the human to completely intervene if they wanted to.

BTW Air France 447 went down because the pilot was trying to pull up out of a stall. BIG mistake. I'm no pilot but I know you are suppose to dive into the stall to build speed because that what a stall is...a lack of airspeed. Any rookie pilot would know this and the captain of this one made a huge mistake.

[Hmac]

I have been a pilot for more than 40 years. I do, however, confess I've never "flown by wire".

I can't see any correlation between engineering an automobile and a 90 ton airliner. Setting operating environment, and the 3D vs 2D differences aside, a modern airliner is going to have different response to control inputs than the automobiles you're used to designing, and the necessary response of those control also has to be more precise on your car than on an airplane that size. Not to mention the limitations that physics imposes on the engineering of a vehicle 50 times the size.

I get that you don't want to trust a computer to fly the plane that you're in. Each to their own. My confusion with your argument is the implication that this was something some crackpot aeronautical engineer dreamed up and slapped on their fleet of $85 million airplanes without testing or input from the dizzying array of engineers and aviation professionals a company like Airbus has at their disposal.

Again, I'm only addressing your statement "Stuff like that seriously makes me wonder if the engineering team that designed the contol system had any experience what so ever flying/driving a vehicle. Or if they even solicited input from experienced individuals." If the unimaginable scenario you're wondering about were true, then I agree, that would be scary. OTOH, Airbus' penetration in the industry (they outsell Boeing) and their safety record pretty much indicates that fly-by-wire is a viable engineering element in modern airliners, your misgivings aside.

Air France 447 shows the opposite of your assertion. In that case, the pilot crashed the plane, not the computer. The computer was trying to keep him from doing so.



/

[Honu]

well great footage and fun to watch :)

I only flew small planes growing up with a pilot as a dad my uncle a pilot my cousin a pilot I had been up quite a bit in small planes the best was a satabra ? or something like that was cool my uncle had

way back in the day when the pilots kids could come up in the cockpit with their dad and watch them land and fly along was really really fun for me when I was growing up nothing like the view from up front
he flew for United retired some 25-30 years ago so we are talking over 30 years ago when I used to be able to be up front :)

[CarlosDJackal]

What can I say, I don't trust computers that have the ability to completely overide a human's input on a device that is transporting them. Especially when the computers decisions are based upon sensors manufactured by humans...

I guess we never should have fielded any of the Stealth aircraft. Someone call the uneducated Aerospace Engineers and tell them they did it all wrong.

According to some expert from the automotive industry they should immediately ground all the F-117s and B-2s until they rip out the fly-by-wire systems and replace them with this magical hydraulic assist stuff that they use for car steering wheels.

OMFG!! Can you be anymore arrogant? :rolleyes:

BTW, Air France 447's pilots ignored two stall warnings and failed to watch their airspeed. In the type of conditions they were in one of them should have transitioned to IFR. Pilot error is unfortunately the biggest cause of aviation disasters. In this case, they trusted their senses instead of their instruments.

Also, the primary initiator of the accident turned out to be faulty pitot tubes - not the computers. BTW, even if all you had were your beloved hydraulic assist systems, you would still be using pitot tubes.

[An Undocumented Worker]

Apparently I opened pandora's box on a controversial subject. I have no intention of offending anyone, and I should have stated my opinion in a different manner. I come across a lot of instance where I think to myself "what was the engineer thinking?" That video brought that thought to my mind. For those of you who were offended by my comment I appologize.

As for the Pitot tubes, the data from them is valuable to making proper decisions, both to the computer and the pilot. I am of the belief that the sense of touch is also a valuable source of information for Humans, to handicap that point of reference on machine that transports people appears short sighted to me.

As was pointed out earlier in this thread those stealth fighters were designed in a manner that made them inherently unstable thus necessitating the use of flight computers to keep them flying. I can understand that need given the unique challenges such aircraft designs create. Airliners on the otherhand from what I understand are designed to be inherently stable, which makes me ask why would it's flight computer needs to be able to completely overide a pilots input.

To be perfectly honest I would love to hear about the experiences from a pilot familiar with such aircraft and to get their point of view on the subject, as I am always open to changing my opinion when given solid evidence that contradicts my viewpoint.

My opinion is more aimed towards the growing number of computerized nannies that people are interacting with at an increasingly frequent rate. It just so happens that aviation was the first to adopt such devices and engineering methods. I personally do not embrace this avenue of change.

At its most basic form this removal of human control, at least from my perspective seems very much like the practices adopted by politicians to slowly remove the ability of people to control even their daily lives. That right there is probably the root of why I distrust such devices designed to improve safety in an intrusive manner, because even they are fallible. (again, none of this is meant to be a personal affront to anyone, if anything it stems from my thirst for knowledge, so please don't take offense, It just so happens that I occasionally insert my foot squarely in my mouth:o)

[Hmac]

As for the Pitot tubes, the data from them is valuable to making proper decisions, both to the computer and the pilot. I am of the belief that the sense of touch is also a valuable source of information for Humans, to handicap that point of reference on machine that transports people appears short sighted to me.


A fundamental concept in instrument training is "partial panel" instruction - the ability to assess aircraft flight condition and fly it when one or more instruments are covered up by the instructor and the ability to assess the whole panel critically so that erroneous information can be picked out and discarded. The Air France pilots ignored a lot of instruction, simulator time, and some very basic rules of flight in order to put that plane in the Pacific.

As for haptics, how about surgery? State of the art requires that the entire operation be done from outside the body with 18-inch long instruments instead getting the hands and fingers in there. And the benchmark of surgical precision, the DaVinci robot provides no tactile feedback at all. I think your concerns in the sense of touch arena are a little overblown. Valuable input? Yes. Critical input? No.

Just out of curiousity, do you think that power steering on a car is a good thing or a bad thing?

[CarlosDJackal]

Apparently I opened pandora's box on a controversial subject...

It's only controversial to the inexperienced. Those of us who have actual flight experience under both VFR and IFR conditions understand where the human being ends and the machine begins.

Instrument rated Aviators are trained to understand that there are times when instrument readouts do not lie and when they do. This comes from good training (I flew the Instrument Simulators on my own time) and experience.


...As for the Pitot tubes, the data from them is valuable to making proper decisions, both to the computer and the pilot...[/SIZE][/I]

Most aircraft have multiple pitot tubes for a reason. A perfect example of this is the F117. This gives that aircraft the redundancy to avoid the type of issue this Air France flight experienced.

As developed by Jimmy Doolittle a long time ago, you cannot fly IFR with the use of only a single instrument. You must do so with input from multiple instruments. In Instrument training, they either cover up an instrument, or in the case of a simulator - make it fail. This is to see if you can determine the correct situation from the others.

For example, if the Airspeed Indicator is not properly working (IE: pitot tube inoperative); you can identify if you are maintaining, gaining or bleeding off your airspeed from the other instruments (IE: Vertical Speed Indicator (VSI) and Attitude Indicator). A VSI that shows a climb and an Attitude Indicator that verifies a nose-high attitude verifies this.


...I am of the belief that the sense of touch is also a valuable source of information for Humans, to handicap that point of reference on machine that transports people appears short sighted to me...

This is a false assumption that has been proven time and again by Full Motion Flight Simulators. If you watch from the outside, you will note that there are times when the simulator stays at an angle. To the outside observer this looks like the simulated aircraft is at an unending turn, climb or dive.

But if you look at the simulator controller's panel, you will see that the "flight" is straight and level as far as the occupants are concerned. What has happened is the machine has fooled the occupant's three primary motion senses (Inner Ear, Proprioceptive and Visual) into thinking they are straight-and-level when in fact they are not.

Flying "seat of the pants" (Proprioceptive) is fine when you are under visual rules (or driving a car) and you have enough points of references that you can check against. By continuously monitoring your relationship to the ground, you can make corrections in your flight attitude to stay flying.

Most pilots have flown into the ground, into the ocean, stalled out, went inverted or flew right into a mountain because they trusted what their body told them instead of what their instruments.

When your VSI is showing you a decent of 1000 feet per minute, an Airspeed Indicator that is telling you that you are gaining airspeed, and an Attitude Indicator that indicates you have a nose-down attitude; this is what is known as a clue!!

[An Undocumented Worker]

Carlos, thankyou for taking the time to explain that, and after talking to some other people with more knowledge on the subject than I,
I have concluded that my perceptions and assumptions on the subject at hand do not scale up to larger vehicles than what I am used to dealing with.

So I'll be at the stove boiling my shoes for dinner.

[militarymoron]

interesting discussion. i'm an aerospace engineer, so i find this fascinating. from my observations over about 22 years in the aerospace/defense industry, the majority of mistakes/errors i've seen in just about everything were attributed to human error, not a failure in something mechanical. no doubt, mechanical systems do fail, but that's why you engineer redundant system into them, specify maintenance and inspection schedules, etc. you also need to understand their limitations.
taking an everyday example - just look at the percentage of traffic accidents caused by something mechanical on a car failing vs. a failure in human judgement.
when it comes to human safety (as on an airliner), i think that it's important to have redundant systems (human or machine) to reduce the chances of disaster happening should one or the other fail. and if so, the ability to override one or the other is necessary.

[Hmac]

It's only controversial to the inexperienced. Those of us who have actual flight experience under both VFR and IFR conditions understand where the human being ends and the machine begins.

Instrument rated Aviators are trained to understand that there are times when instrument readouts do not lie and when they do. This comes from good training (I flew the Instrument Simulators on my own time) and experience.



Most aircraft have multiple pitot tubes for a reason. A perfect example of this is the F117. This gives that aircraft the redundancy to avoid the type of issue this Air France flight experienced.

As developed by Jimmy Doolittle a long time ago, you cannot fly IFR with the use of only a single instrument. You must do so with input from multiple instruments. In Instrument training, they either cover up an instrument, or in the case of a simulator - make it fail. This is to see if you can determine the correct situation from the others.

For example, if the Airspeed Indicator is not properly working (IE: pitot tube inoperative); you can identify if you are maintaining, gaining or bleeding off your airspeed from the other instruments (IE: Vertical Speed Indicator (VSI) and Attitude Indicator). A VSI that shows a climb and an Attitude Indicator that verifies a nose-high attitude verifies this.



This is a false assumption that has been proven time and again by Full Motion Flight Simulators. If you watch from the outside, you will note that there are times when the simulator stays at an angle. To the outside observer this looks like the simulated aircraft is at an unending turn, climb or dive.

But if you look at the simulator controller's panel, you will see that the "flight" is straight and level as far as the occupants are concerned. What has happened is the machine has fooled the occupant's three primary motion senses (Inner Ear, Proprioceptive and Visual) into thinking they are straight-and-level when in fact they are not.

Flying "seat of the pants" (Proprioceptive) is fine when you are under visual rules (or driving a car) and you have enough points of references that you can check against. By continuously monitoring your relationship to the ground, you can make corrections in your flight attitude to stay flying.

Most pilots have flown into the ground, into the ocean, stalled out, went inverted or flew right into a mountain because they trusted what their body told them instead of what their instruments.

When your VSI is showing you a decent of 1000 feet per minute, an Airspeed Indicator that is telling you that you are gaining airspeed, and an Attitude Indicator that indicates you have a nose-down attitude; this is what is known as a clue!!


Nice explanation.

[rjacobs]

Sorry, a bit late back to the party. Been out flying airplanes.

We dont fly large airplanes(or any airplanes in IMC for that matter) based on feel or sensory perception, we fly them by watching the instruments. Its completely different than driving a car and there is no correlation IMO.

The aircraft I currently fly gives us feel of the ailerons by using some springs to provide tension on the cables as we deflect the yoke further and further, air loading on the ailerons does not change how the yoke feels. Our brakes are complete brake-by-wire, they also use springs to provide feedback of how hard you are pushing the brakes. I do not fly a fly by wire aircraft, however the cables run from the controls run out to hydraulic actuators in the wing. If we had FBW the airplane would fly(and feel) exactly the same.

We also do not hand fly airliners very much, probably about 10-20 minutes on each flight on average. So who cares how the stick works? No pilot that I know really cares. Its not like we wont fly an airplane because of how the stick works. We simply want to know everything about HOW that system works, failures, fixes, etc... The airbus stick doesnt move when the autopilot is engaged, neither do the throttles when the the auto-throttles are engaged.

From a pilots perspective it takes you about 30 minutes to get used to the side stick. Everybody that I know that fly's airbus's absolutely loves the airplane.

Boeing's FBW is completely different than airbus's, but at the same time it does the same thing. They use electric motors(I believe, im not a Boeing guy) to provide feedback into the yoke.

[pilotguyo540]

This is proof that we can't just enjoy something.

http://www.youtube.com/watch?v=lxFrXuly_B0&feature=youtube_gdata_player