A330 Flight Control System

[Jule Kue]

Everyoneis bashing Boeing right now, but is there any real difference in the growing pains of the 737 Max vs the computer glitches that caused the pitch down incidents on the Quantas [sic] A330s?

-David

Qantas flight 72 was operated by an A330-300. It left Singapore on October 7, 2008 on a flight to Perth. This airplane had no problem on takeoff as the MAX aircraft did. Instead, it was cruising along at 37,000 feet near the coast of Western Australia when things started to go wrong.

The pilots tried to counteract the airplane, but for 2 seconds, they could not. Then the airplane responded and they went back to normal flight. Two minutes later, however, a less severe pitch down command came in. They recovered once again and diverted immediately. The airplane landed without further incident.

Unlike the 737 MAX, the A330 family was far from being a brand new airplane. The first A330 was delivered more than 15 year before this incident. In the 28 million plus flight hours between then and 2008, nothing along the same lines had ever happened.

But looking at the way this airplane was designed and how training was pushed out, it seems to have been done in a rush and could, to put it mildly, have been thought through better. By grounding the airplanes, the authorities are effectively hitting the pause button to let training and automation catch up to the airplane.

If I remember correctly, the captain was trying to put the nose down, but the first officer was pulling up and the fly-by-wire system just took the sum of their inputs without giving any sensory feedback. So by the time they figured out what was actually happening, they were too close to the ground to do anything about it.

For a comparable issue other than the A330, consider the Turkish 737 in AMS. The auto throttle flare-mode power reduction got triggered early by a single false radar altimeter, and the pilots never pushed the power up.

Thank you for this clear and well researched explanation. I have been scratching my head about the similarities and have not seen this talked about anywhere else. Kudos to you for taking the time to address it. Guess I have a new aeronautics website to follow, Cranky! I look forward to it.

Boeing has not fixed the real problem. The mew engine size and wing placement is not being changed. All Boeing is doing is installing a computer work-around. So from my point of view. the aerodynamics will remain the same. Boeing needs to redesign the wing-engine placement or, even better, design a new modern airframe.

ITS BETTER SCRAP THIS MODEL, N TO MOVE ON, MANUFACTURING FOCUSSING ON OTHER SUCCESSFUL MODELS OF BOEING, WAT BOEING HAD SO FAR VRY TRULY ATTRIBUTED TOWARDS SAFETY N QUALITY N UPRIGHTNESS IN AVIATION INDUSTRY..

I AM FED UP WITH ALL THE OUT CRY ABOUT BOEING AND NOTHING IS SAID ON THE CRASHES AND ISSUES CONCERNING AIRBUS. TWO OR THREE AIRBUS PLANES HAVE CRASHED BECAUSE OF THE SPETO TUBE ISSUES THAT AIRBUS KNEW ABOUT. EVERYONE GIVES THEM A PASS AND I WOULD LIKE TO KNOW WHY? . RECENTLY AIRBUS PLANES HAVE BURNED . THAT COMPUTER GLITCH ON FLIGHT 72 HAS NOT BEEN DIAGNOSED AND CAN STILL BE A ISSUE WITH THEIR PLANES. IT CAN HAPPEN AGAIN. JUST WATCH AIR DISASTERS AND GOOGLE IT. JUST BECAUSE THIS HAPPENED A WHILE AGO DOES NOT MAKE IT OK.

When performing a pitch up maneuver, I pull the joystick a little bit and the plane responds quite well, too sensitive. And when joystick returns to neutral, pitching continue for a time, so unstable.

Hello eric,

Did you apply the settings we recommend for control on manual vol 1?

We are aware of the flare logic not being complete and hopefully will get a chance to have a closer look into it at some point.

About the FCU, there are two knobs under the glareshield that control the brighteness settings on the FCU. The right knob will control the brightness of the display. Have you tried that?

Hello eric,

Did you apply the settings we recommend for control on manual vol 1? We have consulted many real world pilot advisers to gain feedback on flight control behavior. Also, it's good to remember that the A330 is a big heavy aircraft that has lots of inertia so the movement would not stop suddenly when stick gets into neutral position. Think of stopping a light shopping cart and a heavy shopping cart.

We are aware of the flare logic not being complete and hopefully will get a chance to have a closer look into it at some point.

About the FCU, there are two knobs under the glareshield that control the brighteness settings on the FCU. The right knob will control the brightness of the display. Have you tried that?

"We have consulted many real world pilot advisers to gain feedback on flight control behavior. Also, it's good to remember that the A330 is a big heavy aircraft that has lots of inertia so the movement would not stop suddenly when stick gets into neutral position. Think of stopping a light shopping cart and a heavy shopping cart."

"The roll rate requested by the pilot during flight is proportional to the sidestick deflection, with a maximum rate of 15/s when the sidestick is at the stop"

So I don't think your argument is correct. The A330 has larger flight control surfaces to counteract that "larger shopping cart" inertia to meet the FBW commanded roll rate.

But again, I would love to have a statement from one of your real world pilots on that. Thank you.

For what it's worth, I'm experiencing this too. The flight control surfaces (in external view) seem to lag behind the control inputs significantly. It makes the aircraft very difficult to hand fly precisely. My controls are set up exactly as the manual suggests.

I agree with eric_jeppesen about the pitching motion continuing for much longer than expected. An extremely brief pitch up on the sidestick causes nothing to happen initially, then after a delay the aircraft starts to respond, but continues pitching for much longer than the sidestick deflection occurred.

I absolutely agree with you. Modern heavies control response are designed to be responsive - certainly no lag response. I have a few friends flying Quantas A330's in real life and they assured me that the control response has no noticeable lag. I have watched the few videos of the Aerosoft A330 available on Youtube, and I have to say , in my opinion, that this aircraft is not hand flyable!

While I disagree with the fact that you are basing your assertions on watching a video instead of having purchased the product, I actually agree with your post. Hand flying this aircraft, especially on approach, seems very difficult. It has caused me to be super unstable on several approaches which is what TheFlightsimmer was experiencing in his streams, I believe.

Yes indeed. I normally use full sensitivity and a very small deadzone, but changed them as the manual advises for the A330. The recommended settings reduce the sensitivity of the flight controls, but do nothing to affect the (apparent) latency between input and aircraft response.

We will have another look into this just to make sure that nothing for example changed between the test that our real world pilots made and the release version coming out and get the very latest feedback from our A330-300 pilot advisers with the released version on this.

I will add myself to the list of those that notice slow response from the aircraft after input has been made. At first I thought it might be the larger aileron travel on the honeycomb yoke, but there certainly is a delay. The sidestick animation corresponds perfectly to my yoke inputs. While I think with a little getting used to hand flying is possible it sure feels a lot different than all the other planes I have (including the Aerosoft A320) and there isn't much difference among the others. I think the pitching thing is due to auto-trim? Perhaps switching FBW off might help for the time being?

Piling on, there's something odd about the continued motion after a return to neutral stick (not with a max deflection snap to center, but a calm measured return to center which even in a non-FBW would be expected to at least almost null rates). Besides that it did fly fine on departure, but on landing I had severe roll delay coupled with pitch over-sensitivity, and had there been any gusts or crosswinds I would have had to go around.

Thanks all you captains replied above! Made me convinced that I'm not alone in encountering this problem.

A330 is one of my favourite airplanes and I look forward to have a flyable A330 in FSX/P3D for many years. I hope and thank the Aerosoft team for improving this product in subsequent updates.

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