Archie From Mexico, joined Aug 2000, 228 posts, RR: 0 Posted (11 years 9 months 1 week 3 days 6 hours ago) and read 2505 times:
Hello,
I want to ask why people criticize Airbus saying that it is not for REAL pilots. What would be the difference between an Airbus A330 FBW and a B777 FBW.
Don´t want to start a war, just curious.
Thanks
Archie
King767 From , joined Dec 1969, posts, RR: Reply 1, posted (11 years 9 months 1 week 3 days 6 hours ago) and read 2249 times:
Well when people say "pilots dont actually fly airbuses", is because airbus planes are controlled by sidesticks which are like joysticks located at the pilots side. On the 777 the steering controls are right in front of the pilot like in most planes. My personal opinion is the same with many that "pilots dont actually fly them".
ZRH From Switzerland, joined Nov 1999, 5464 posts, RR: 46 Reply 3, posted (11 years 9 months 1 week 2 days 19 hours ago) and read 2214 times:
I talked with a pilot who flow 747-300 and now 330/32x. He told that in fact there is a difference between the old 747 and the Airbus, but they also fly the aircraft with the sidestick not only the computer. It is only a matter of habituation. If the weather is good they make all landings by "hand" and not by computer. In this case there is no difference of flying a FBW 777 with "normal" controles or a Airbus with sidesticks.
Minuteman From United States of America, joined Aug 2000, 271 posts, RR: 0 Reply 4, posted (11 years 9 months 1 week 2 days 10 hours ago) and read 2185 times:
Yes, this is a touchy subject for some reason...
I believe the main point of contention is who has final authority over the flight control...the pilot or the computer. Boeing's belief is that the pilot should always be able to override the computer in case of a problem. Correspondingly, Airbus operates under the belief that the computer should have final authority and correct the pilot.
Additionally, the sidestick on the A320 (for example, and probably most other aircraft) operates on a gain schedule...that is, the computer takes into account all the factors that can influence a control surface's effectiveness and then interprets the stick command to produce a consistent response (i.e. a certain stick deflection will attempt to produce the same body pitch or roll rate under all conditions) It's intended to make flying the jet easier and possibly more efficient.
One of the main differences between sidesticks and control columns is in the user interface. The CAPT and F/O control columns are ganged together and provide proportional force feel to simulate a physical connection to the control surface, while the CAPT and F/O sidesticks aren't coupled and do not provide any kind of feeling for the control surface.
AA737-823 From United States of America, joined Mar 2000, 4857 posts, RR: 13 Reply 6, posted (11 years 9 months 1 week 14 hours ago) and read 2136 times:
Not to single you out world traveler (no offense), but here is my knowledge:
The computer on the airbus does have final say in what the plane does. This is why the plane at fornbourough went down. The pilot wanted to do a fly over, and the computer took that to mean "we are now landing." And the computer landed the plane in spite of the pilot pulling up on the control stick.
Kangar From Ireland, joined Feb 2000, 395 posts, RR: 0 Reply 7, posted (11 years 9 months 1 day 2 hours ago) and read 2077 times:
Guys, the computer does not have the final say, the fact was, the computer was incorrectly set, the the aircraft did as the pilot told it to. It did not prevent the pilot from stopping it, the mistake in setting up the computer was realised too late. The pilot pulled up, but since he didn't alter the computer instructions in the predefined manner, the computer continued to do what it was commanded to do.
JETPILOT From United States of America, joined May 1999, 3128 posts, RR: 37 Reply 8, posted (11 years 9 months 1 day 1 hour ago) and read 2090 times:
The Airbus computer ABSOLUTELY DOES have the final authority over the control of the aircraft.
The computer will not allow the aircraft to be flown outside it's flight envelope.
In addition pitch, roll, and yaw rates of all Airbus FBW aircraft are identical. So there are no flight characteristic inconsistencies when transitioning from one plane to another.
kangar: The inherent flaw in Airbus' philosphy is the pilot flies the computer, and the computer flies the plane.
In a Boeing If you push the throttles foward, and pull back on the yoke the plane will climb weather the computer likes it or not.
This is why Airbus will NEVER be a pilots plane.
I am not Anti Airbus. As an airline pilot I prefer to have the freedom to make decisions without seeing what the computer wants to do.
WorldTraveller From Germany, joined Jun 1999, 624 posts, RR: 6 Reply 9, posted (11 years 9 months 22 hours ago) and read 2075 times:
JETPILOT, could you please provide some backup like an operations manual that on Airbus FBW aircraft the computer cannot be overridden??
I highly doubt that since I've heard the opposite. I think it was in a Video about flight training on the A319.
If you are right, accidents like the Egyptair suicide are not possible on Airbus FBW aircraft.
I understand that you, as a pilot, like to have full command of an aircraft, but you also have to admit that most crashes unfortunately are due to HUMAN errors. Airbus just wants to reduce the errors on the human side...
JETPILOT From United States of America, joined May 1999, 3128 posts, RR: 37 Reply 10, posted (11 years 9 months 21 hours ago) and read 2082 times:
This is really getting too technical to discuss in a forum atmosphere.
The different systems on the Airbus have certain modes of operation that are user controlled. As it implies the user controlled functions can of course be overidden. I cannot go into the specifics because I only have about 25 hours in the simulator, and that was in 1993. I do not remember much.
I do remeber the flight envelope protection cannot be overiden.
Human error is the largest contributing factor in airplane crashes. However the large majority of accidents involve CFIT (Controlled Flight Into Terrain). Not pilots ripping apart airframes because they exceeded airframe limitations.
We won't go into weather Egyptair can be reenacted in an Airbus because we have no idea what happened to Egytair.
If commiting suicide is your goal, shutting off start levers will always conclude in certain death for all aboard.
I feel like people think Airbus pilots are like Dr. Chandra dealing with HAL in 2001 A Space Oddysey.
WorldTraveller From Germany, joined Jun 1999, 624 posts, RR: 6 Reply 11, posted (11 years 9 months 17 hours ago) and read 2106 times:
Hi JETPILOT, thanks for your reply.
I just found a VERY interesting article dealing with exactly the topic we're discussing and yes, it seems that the computer has the final word (or action) on Airbus FBW aircraft as opposed to the B777, where pilots can override manually.
It's a rather long article, but I highly recommend that everyone reads it since it is very unbiased and states the advantages of both Airbus' and Boeings philosophy. The article also deals with the Habsheim accident and the question whether the AA 757 Cali accident would have been prevented by an Airbus' FBW system.
Here it is: (Please take the time to read it, this is a technical forum, after all!)
begin of quote
"Unlike Airbus, Boeing lets aviator override fly-by-wire technology .
Monday, March 20, 2000
By JAMES WALLACE
SEATTLE POST-INTELLIGENCER REPORTER
MIAMI -- As the Airbus A320 jetliner descended through 3,000 feet on its final approach to the airport, co-pilot Rudy Canto glanced off to the right and spotted a regional jetliner bearing down on the Airbus plane.
The regional jet also was descending, and the two planes were seconds away from a midair collision.
Canto barked a warning and the pilot immediately pushed the side-stick controller hard left and pulled back as far as it would go and held it there -- an abrupt maneuver that should have resulted in the plane's losing lift and stalling
But one of seven flight-control computers on the A320 took over and the Airbus plane climbed sharply and turned away from the regional jet just in time to avoid a collision.
No report was filed on the near midair collision. The flight was actually a demonstration for a group of journalists earlier this month in one of the $12 million A320 flight simulators at the new Airbus Industrie training center in Miami.
What happened in the simulator, though, was no different from what would have occurred in the sky. And it is at the heart of an ongoing debate in aviation today:
Should pilots or a computer have the ultimate control authority over a commercial jetliner as the plane approaches its design limits in an emergency?
Airline passengers can't see it, but this is the most significant difference between Boeing and Airbus planes.
Dramatic advancements in technology have made it possible for planes built by either manufacturer to be flown by computers from shortly after takeoff through the landing.
But Airbus has taken a much different philosophical approach to using computers than its rival. The European airplane maker designed its new fly-by-wire jets such as the A320 with built-in hard limits, or "protections."
The Boeing Co., on the other hand, believes pilots should have the ultimate say. On Boeing jets, the pilot can override onboard computers and their built-in soft limits.
"It's not a lack of trust in technology," said John Cashman, director of flight-crew operations for Boeing. "We certainly don't have the feeling that we do not want to rely on technology. But the pilot in control of the aircraft should have the ultimate authority."
On all Airbus planes other than the older A300 and A310, computers prevent the pilot from putting the plane into a climb of more than 30 degrees where it might lose lift and stall. The maximum bank or roll allowed is 67 degrees. The plane's nose-down pitch is limited to 15 degrees. There are protections against overspeed.
And the computer won't allow the plane to make any extreme maneuvers that would exceed 2.5 times the force of gravity.
(As a plane maneuvers, for example turning from side to side or up and down, the forces against it can be measured in units of gravity called "g" forces. One "g" is equal to the force of gravity on earth.)
Consider the near-miss incident in the Miami flight simulator.
When the pilot yanked back hard on the control stick to avoid the simulated regional jet, one of the computers on the A320 applied full thrust to the plane's two engines. At the same time, the computer retracted the speed brakes on the wings, which had been deployed to slow the plane for landing. But the computer did not retract the plane's wing flaps, which had also been extended for landing. The flaps provided added lift during the steep climb.
Most important of all, the computer limited the angle of the plane's climb to 30 degrees to keep it from stalling and falling out of the sky.
"If we had been in a conventional plane, we probably would have stalled and crashed," Canto said.
But Cashman said such limits keep a plane from performing at its absolute capability.
"When you fully automate and protect the system, you have to take away some of the capability," he said.
"It makes no sense to us to limit the pull up capability, say to miss another airplane or the ground. . . . We feel the pilot should have that capability and should be able to achieve it by use of normal controls, providing cues that he is getting close to those limits but letting him exceed them if necessary."
These so-called "cues" tell the pilot the plane is approaching certain speed, load or attitude limits. As the jet nears its stall speed, for example, much more force is needed to pull back on the control column. The same is true as the "g" forces on the plane increase.
Planes are generally designed structurally to have more capability than what the book says, Cashman noted.
If the pilot can pull an extra "g" during the initial part of an upset (loss of control) when the airspeed is low, Cashman said, the pilot may avoid getting into a more serious high-speed recovery.
"By limiting the amount of 'g' you pull, you may prolong the recovery," Cashman said.
He recalled the case of a China Air 747 that tumbled out of control over the Pacific in 1985. The pilots were able to recover by subjecting the jumbo jet to upward of four times the force of gravity.
John Lauber, former board member of the National Transportation Safety Board and now vice president of safety and technical affairs for Airbus, said good arguments can be made for either the Airbus or Boeing cockpit philosophy on soft or hard limits.
"But hard protections are a better way to address loss of control," he said.
Though fly-by-wire was used on jet fighters and on the supersonic Concorde, the first Airbus plane with the technology was the A320, which entered service in 1988. The same system is also used on the Airbus A330 and A340 widebody jets.
Fly by wire simply means that computers on the plane transmit the pilot inputs into electrical signals that are sent through wires to actuators that move the control surfaces.
On conventional planes, the flight-control surfaces are moved by hydraulic devices controlled by cables that run through the airplane.
Airbus also eliminated the wheel-and-control column, or yoke, that is used on all Boeing jets. Instead, Airbus pilots control the plane by moving a small, hand-held joystick off to the side.
"The benefits are numerous," Canto said of the Airbus system. The computers, for example, automatically trim the plane even when it is being flown by the pilot. The trim system on other planes must be operated by the pilots when the plane is not on autopilot.
"It's like having power windows in your car," said Larry Rockliff, vice president of the Airbus training center in Miami who has served as an instructor for every model of Airbus plane. "It reduces the pilot workload."
The only Boeing plane with fly-by-wire technology is the 777.
Cashman, who was chief pilot for the 777 program, said Boeing could have designed the 777 with the same hard limits as those in the Airbus planes.
"They could have been absolutely identical, but we chose to go a different path," he said. "It was based on what our customers wanted, and what we believed was the safest way to operate jet transports."
The Airline Pilots Association, the largest pilot union, recently published a series of technical papers on the issue.
"The pilots had strong opinions -- both ways," said Capt. Paul McCarthy, executive air-safety chairman for the union.
"There are good arguments on both sides," he said. 'Both make legitimate points. And both sides are correct. . . . It's a good, healthy debate that will continue for the next five to 10 years until everyone is confident which way we should go."
The study by the pilots union recommended that Boeing and Airbus incorporate the best of both cockpit designs in future planes.
Statistically, the accident rates for Boeing and Airbus planes are about the same.
"Both types of planes are extremely safe," said Bob Vandel, executive vice president of the non-profit Flight Safety Foundation in Arlington, Va.
He said the pilots with whom he talks are pretty much divided about whether they prefer the Boeing or Airbus way.
'The envelope protection Airbus has is very good," he said, "but some pilots want total control. They don't ever want to be completely out of the loop."
Vandell said he cannot recall a particular crash of a Boeing or Airbus plane in which a case could be made that, had the plane used the other manufacturer's system on limits, the crash could have been prevented.
But there has been much discussion in aviation circles, he said, about the Boeing 757 that crashed into a mountain ridge while trying to land at Cali, Colombia, in 1995. All 159 people on the jet were killed.
The plane's ground-warning system alerted the crew they were about to hit the mountain, but the crew did not retract the plane's speed brakes as they tried to climb. They hit the mountain ridge about 250 feet from the top.
The speed brakes on an A320 would have been retracted automatically, Airbus points out.
But Cashman said Boeing believes the jet would have hit the ridge even if the speed brakes had been retracted.
Airbus planes with their fly-by-wire technology and hard limits have also crashed. Six of the A320s have so far been lost.
One of the very first A320 jets crashed shortly after the jet entered service in 1988, raising many questions about the Airbus philosophy.
The pilots were making a low and slow-speed pass at an air show in Habsheim, France. The subsequent crash was captured on video. It shows the Airbus plane disappearing into trees, as if it were making a very slow landing. Then a huge cloud of smoke billows from the forest.
Though the A320 was full of non-paying passengers, all but a few survived.
Lauber said the pilots were supposed to fly by with the gear down at about 100 feet. Instead, they came in at less than 30 feet off the ground. When the plane gets below 50 feet, the computer assumes the pilots are trying to land, Lauber said.
"The fact is, the plane did exactly what it was supposed to do," he said. Only it landed in the tress.
Airbus learned much from that incident, Lauber said.
Until the crash, he said, there was a "genuine psychology" around Airbus that it had designed a crash-proof airplane because of the hard protections.
"The repercussions from that accident continue to reverberate," Lauber acknowledged.
He and others at Airbus know that should one of the Airbus fly-by-wire planes crash in the United States, television will be showing endless video of the Habsheim incident, questioning whether Airbus has placed too much faith in computers."
end of quote
Pretty good for a journalist's writing (and it's from Seattle, after all)
N766AS From , joined Dec 1969, posts, RR: Reply 12, posted (11 years 9 months 10 hours ago) and read 2031 times:
James Wallace is one of my favorite Seattle journalists. Great job on posting this extremely relevant P-I story here.
As for me, I prefer the 'Boeing Way'.
Learjetman From , joined Dec 1969, posts, RR: Reply 16, posted (11 years 8 months 4 weeks 1 day 20 hours ago) and read 1995 times:
I don't know if anyone has seen it yet, but there is a great article in the current issue of Aviation Week dealing with this very subject. The article talks at length about the envelope protection of the Airbus. The article calls this "hard" protection and refers to the Boeing approach as a "soft" protection. The FBW 777 can be flown at the ultimate aerodynamic limit but it will require the pilot to exert a great deal of force on the controls (up to 60lbs.) amidst a chorus of aural warnings and flashing annunciators (DO I WANT TO DO THIS!)
The article does mention the 757 crash in Cali, the spoilers were found in the deployed position. The Airbus features automatic retraction of spoilers when the aircraft enters into this situation (evasive manuvers @ low speed). The article states that Boeing is considering this feature in later mdels of the 777. I would be in favor of this addition, but I favor 12,000 hours of experience pulling back on the yoke and pushing the throttles, not binary wizardry.
VC-10 From United Kingdom, joined Oct 1999, 3656 posts, RR: 42 Reply 17, posted (11 years 8 months 4 weeks 1 day 17 hours ago) and read 1978 times:
FG
The a/c didn't make the Gulf Air pilot fly fast & low. I am not blaiming the pilot in this statement as we don't know what happened. I am merely saying you can't blame the AI software.
L-188 From United States of America, joined Jul 1999, 28959 posts, RR: 66 Reply 18, posted (11 years 8 months 2 weeks 6 days 23 hours ago) and read 1931 times:
It is really too early to make any calls at all on the Gulf Air crash.
I do think the Boeing pattern of thinking is the better of the two ways to go. But then again I come from the land of the independent thinking bush pilot. I have a sales video from Airbus that I will have to look at again. They where demonstrating aircraft manuverablity. Keep in mind that that simulator ride the reporter talked about was a controlled and staged event.
It is when I walk into an aircraft cockpit before a flight and see the Windows 98 logo on all of the EFIS displays that I will begin to get really worried.
That thought kind of puts a new meaning in the phrase "Blue Screen of Death"
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
CstarU From , joined Dec 1969, posts, RR: Reply 20, posted (11 years 8 months 2 weeks 3 days 11 hours ago) and read 1890 times:
There's also a conventional backup system on the 777. This consist of hydraulically controlled trim system on the horizontal stabilizer and one cable-driven spoiler on each wing surface.
Skyhooked From , joined Dec 1969, posts, RR: Reply 21, posted (11 years 8 months 2 weeks 2 days 10 hours ago) and read 1874 times:
Guys
Am I glad this isn't turning into another BvsA slugging match .
Here are a few comments to contribute to this debate :
China Air 747 :The crew blew it :They allowed the A/C to be over max alt,with a high pitch angle and a stalled engine.That they went into a diving roll was quite normal owing to the circumstances.God,not fbw or the crew was flying that particular 747.It's quite a tribute to the toughness of the aircraft,though.
L-188,you refer to the sim demo as a"controlled and staged event2 and I can't agree more with you.But look at this one : an A-320 was descending into Montpellier airport when suddenly F/O sighted an gliderstraight ahead and close.The 320 was on autopilot.On F/O's shout,the captain just hit the side-stick to the left,disengaging the autopilot and banking the aircraft to more than 60 degrees in less than a second (I could get the accurate figures if required).They nicked half an inch of the glider's rudder.Talk of a close call!
On the Habsheim accident,may I say this :Just suppose a guy takes an airplane,fill it up with 130 passengers,3 FA friends and takes it to an unknown general aviation airfield to perform some unrehearsed low passes and then gets so excited he decides to fly low,with engines idle,on the wrong side of the L/D curve,...what do you think?...IMHO,he was lucky as the fbw kept the wings level,they never went into the stall.They "landed" on the trees.
As pilots we all have a rather good opinion of our abilities,do'nt we?But nowhere in this thread have I read about the bonus of flight enveloppe protection:just think of a windshear or microburst event .A lot of deaths and a lot of hull losses would have been avoided,had the technology been available earlier.Fly the Atlanta pattern on a 1011,a 747 and sweat.The same situation on an Airbus is a lot easier to manage and get out of.
Having flown both A and B airplanes,plus the Tristar,I admit I liked them all.I still miss (after five years) some of the features of the 744 or the 1011 but I enjoy my 319/20/21 a lot nowadays.
The sidestick does't certainly make me a second rate pilot just because I have nothing between my legs to hold on to.And I believe f-16 pilots feel the same.
Aca320 From Canada, joined Aug 2009, 0 posts, RR: 0 Reply 22, posted (11 years 8 months 2 weeks 2 days 7 hours ago) and read 1861 times:
The fact of the matter is that there are not pilots as such navigating the sky in large commercial a/c however they are flight managment specialists this view is not mine however is the predominatly held mantra of those who run the airline and determine the a/c we buy.It is these people for whom the airbus was built and is the reason ,and this may be sometime down the road that aircraft will be largly antonomous devices under the control off a computer don't think so ask yourself how long an airline can pay its pilots close to half a million a year and stay in business.
DC10 From Canada, joined Apr 2007, 0 posts, RR: 0 Reply 23, posted (11 years 8 months 2 weeks 2 days 1 hour ago) and read 1859 times:
Hi;
I remember an incident on a AF B744 (13/09/1993) at Tahiti: the pilots were landing the plane manually, and the autopilots commanded a go arround (the throttle went to 100%). The pilots try to stop the throttles and to move them back to engage the reverses, but the pilot could stop the number 1 throttle that went to 100%.
The non-symetrical thrust make the plane to go out of the runway and finish in the lagoon:
Boeing has (fortunately) automations. The way to 'think' the job of the pilots is very different, but interesting in the both ways
Regard
DC10
The rapport of the accident (in french unfortunately) is at
http://www.bea-fr.org/docs/f-ta930913/htm/f-ta930913.html <\HTML>
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