off topic Airbus A330

[Coyote Chris]

So there I was this morning watching the news on the telly about Air France 447 and there is Capt. Sully explaining in the simulators for a 747 and an Airbus A330 how the controls in the Boeing for the pilot and copilot are the typical yokes that are interconnected and how the French have chosen to give the pilots two separate joysticks that are not connected.
So one French pilot just keeps pulling back in a stall condition despite 25 warning buzzers that he is stalling....and the other one doesnt do anything.

What happens in an Airbus product when one pilot pulls back his joystick and the other shoves his/hers forward?

I think you can still see this episode on the CBS morning news website.

[AirDOGGe]

Re: off topic Airbus A330

With a modern Airbus the computer is pretty much flying the plane, and you are doing little more than issuing instructions with the stick.

If you tell the plane via the stick to maneuver in a way it's computers have been programmed to recognize as dangerous or out of it's pre-chosen envelope, it won't do it.

Because of this, I assume that if one pilot pulled the stick back, and then the co-pilot pushed his forward, the computer would ignore the secondary, conflicting input signal. Likewise if they somehow manage to move both sticks in conflicting directions at the exact same time, both commands would be denied.

I do not know how you can stall one with such a set-up unless it involved the pitots and/or some other sensor(s) sending false date to the computer.



I've read an experienced Airbus pilot's comment that the control stick of those planes feel more to him like a thruster control rather than a stick or yoke directly connected via cables or hydraulics (or both) to control surfaces.


.

[Bob]

Re: off topic Airbus A330

What I have read is the the pitot tubes were frozen up and sending bogus data to the computers. That is why the flight laws over rode the pilots inputs. The plane wanted to climb as the sensors were reporting the plane close to max speed or something of the sort. Nova had a great special on it. And you can bet that during this time the pilots were very much overloaded.
I am not sure that if the jet had been a Boeing that the outcome would have been any different as they are mostly controlled by computers also. The newer jets that is.

[Bob]

Re: off topic Airbus A330

here is the Nova link

http://www.pbs.org/wgbh/nova/space/crash-flight-447.html

[hg2992]

Re: off topic Airbus A330

If both pilots move the sticks at the same time it is the algebraic sum of the two movements that happens. In other words, if one pilot pushes full down and the other pulls full up, the aircraft will fly level, but if one pilot pulled up to what would be 20 degrees and the other pushes to what would be 10 degrees down, the aircraft would fly 10 degrees nose up.

[shorebird]

Re: off topic Airbus A330

hg2992

Private message sent

Dennis

[Coyote Chris]

Re: off topic Airbus A330

What I have read is the the pitot tubes were frozen up and sending bogus data to the computers. That is why the flight laws over rode the pilots inputs. The plane wanted to climb as the sensors were reporting the plane close to max speed or something of the sort. Nova had a great special on it. And you can bet that during this time the pilots were very much overloaded.
I am not sure that if the jet had been a Boeing that the outcome would have been any different as they are mostly controlled by computers also. The newer jets that is.

Keep in mind that I really enjoy Nova specials but I have to wonder if they didnt make some mistakes, now that we have the voice recordings and the inquiry....first thing that happened after the pitot tubes failed is that the auto pilot turned off....Sully said the third in line pilot was doing the flying and the Capt never took control. The co-pilot didnt either according to the blurb....twice the guy pulled back on the stick despite the 75 (sic) stall warning alarms...Sully said on the evening news today that he had no idea what the guy was trying to do....At Osh last year, I talked to my friend Jeff who is a United 777 capt. (He is also an aerobatics pilot) He says he likes to turn off the autopilot now and then and actually fly the plane. I wonder if those French Pilots need some aerobatic training....looks like from the report, they are going to get alot of high altitude stall training from now on....personally, I would like to see pilots get out of the simulators and into real aircraft and fly them. I was in a special test program at the University of Illinois aviation research lab where we got lots of simulation, but there is nothing like real hands on "recovery from unusual attitudes" practice under the hood.
I still would like to know if the pilots have GPS speeds....those are ground speeds but at least they would have a relative reference.

[AirDOGGe]

Re: off topic Airbus A330

...Capt. Sully explaining in the simulators for a 747 and an Airbus A330 how the controls in the Boeing for the pilot and copilot are the typical yokes that are interconnected and how the French have chosen to give the pilots two separate joysticks that are not connected.

.



That is a very negative issue with the dual joystick layout....NOT KNOWING what the pilot in the other seat is doing with the controls. It ALSO applies to the throttle quadrant and the lack of motion of said controls.


Quoted from an American Airlines pilot used to piloting Boeing products who was riding jumpseat in a 'Bus and observing the computerized operations of such:


"... I still question: Are the pilots REALLY in control? I had a lot of difficulty watching the engine instruments register changes without the throttles moving. I never quite knew what the engines were doing. Why are the throttles locked at Climb Thrust with the engines back at idle? This stuff really conflicts with my "Boeing-warped" mind.

I also had a tough time comparing aircraft pitch/roll commands without seeing a corresponding stick movement. Why, because the other stick doesn't move. How does the other pilot know what the flying pilot is doing?"


(Full discussion HERE: http://www.airlinepilotforums.com/ma...otherwise.html)


This could be a highly-contributing factor to the 447 accident.

After reading Coyote Chris's post... "So one French pilot just keeps pulling back in a stall condition despite 25 warning buzzers that he is stalling....and the other one doesn't do anything",.... and then reading the comments from the ride-along in the Airbus cockpit, It made me think...

......IF the accident craft had been fitted with motorized control joysticks that both moved when force was applied to one like a standard dual yoke, and IF the throttle levers moved with changes in actual engine power settings like mechanical quadrants do, would the other pilot have noticed the condition of said controls, realized the wrong control inputs were being made for their stalled situation and acted appropriately?


Funny how what is suppose to be an advance in technology and design turns into what appears to be as step backwards in progress. Go figure.

[hg2992]

Re: off topic Airbus A330

I think if you asked him if was he thankful for the ride home, and was it more comfortable than a 737 jumpseat.......... He would have said, yes

[First time Juke]

Re: off topic Airbus A330

There was almost identical accident few years before with an MD-80 from Haiti that crashed in Venezuela. Pilot kept pulling and co-pilot told it is a stall...captain insisted it has a flame out on both engines. It landed flat on a field.

[FlyKidChris]

Re: off topic Airbus A330

I am not sure that if the jet had been a Boeing that the outcome would have been any different as they are mostly controlled by computers also. The newer jets that is.

Just to be clear, Bob, which Boeing models are you referring to?

[Bob]

Re: off topic Airbus A330

777 and 787, 100% fly by wire.

[shorebird]

Re: off topic Airbus A330

The control columns the on B777 and B787 are conventional and redundant, nothing out of the ordinary.

[airtj]

Re: off topic Airbus A330

I found a training manual on airliners.net and this is what it said about the sidestick characteristics.


SIDESTICK CHARACTERISTICS
There is no physical interconnection between the sidesticks. Visual monitoring of the other pilot's sidestick input is significantly reduced because of the sidestick position.
With the AP engaged, the sidesticks are locked in the neutral position. This provides a tactile feedback that the AP is engaged and also prevents simultaneous inputs from the pilot and AP.
When the PF makes a sidestick input, an electrical order is sent to the flight control computers. If the PNF makes a simultaneous sidestick input, both signals are algebraically summed and both PF and PNF green lights flash on the glareshield. This situation might occur in the case of an instinctive PNF reaction on the sidestick. If the PNF needs to take control, he must press and hold the take-over pb in order to avoid simultaneous sidestick inputs and announce, "I have control".
In the case of a SIDESTICK FAULT ECAM warning due to an electrical failure,the affected sidestick order sent to the computers is zeroed. This means that the affected sidestick has been deactivated and there is no further procedure associated with this warning.In the case of pilot incapacitation where a sidestick input is being made, or in the
case of a mechanical failure leading to a jammed sidestick, the inputs are again algebraically summed. There is no associated ECAM caution. In either of these cases, the intervening pilot must press the take-over pb to gain single sidestick authority. The pb must be depressed for at least 40 seconds to permanently deactivate the affected sidestick. However, if a sidestick has been deactivated, it may be reactivated by depressing its take-over pb.

[AirDOGGe]

Re: off topic Airbus A330

777 and 787, 100% fly by wire.

This isn't a fly-by-wire issue. It's a visual control "feedback" problem if you will.