A330 Lateral control/PIO

[Sidestick_n_Rudder]

Hi guys,

I am doing the CCQ from the 320 to 330 right now. Whilst overall it's a pleasant experience, I found I have problem landing the thing in the sim.

The roll control of the sim is very sluggish ant I tend to get into PIO on short final, esp when have to make adjustments for centerline.

Has anyone had a similar experience, or am I the only dumb guy around? I have flown several a/c types before and never had problem with this. Certainly not on the 320...

Any hints how to prevent it would be appreciated...

Cheers!

SnR

[hikoushi]

Basically if you start to get a roll PIO on final, let go for a couple seconds. Also until you get very used to the feel, try to correct in a single axis at a time. As in, let go until the thing stops wallowing, then make a small fingertip correction to pitch only IF REQUIRED, and the a SEPERATE small fingertip correction in roll only. Remember to center the stick between all corrections, and let it "live" in the center.

While the 330 is supposedly programmed to have similar roll rate responses to the 320, it is a big, heavy airplane. It does not require as active a hand on the stick, as it has a lot of momentum and will resolve most small disturbances on its own. Let it do its own thing in turbulence, giving it "guiding" corrections to PATH deviations while allowing it to settle most minor attitude disturbances on its own. In normal law, let the airplane do the grunt work for you. If your approaches all end up requiring lots of corrections down low, you are over controlling from earlier on than you think you are.

Again if all else fails just let go completely, take one deep breath, exhale, and put your fingertips back on the side stick and correct one axis is at a time, always coming back to center.

And no the real airplane is not as squirrelly as most 330 sims seem to be!

[Centaurus]

Were you in partial IMC with no visible horizon at the time you had the jitters (PIO)? As a sim instructor we see PIO very often in the 737 if the instructor sets (say) 3 kms viz and nothing else.

As the approach lights come into sight the PIO sets in with a vengeance and occasionally one sees angles of bank of +/- 45 degrees and even the occasional loss of control. All because on first becoming visual with the HIALS there is no visible horizon at 3 kms viz.

As one reply said, momentarily relax your vice like grip on the stick and the PIO should reduce but it will immediately come back if you start to over control again. Get your sim instructor to let you fly four or five ILS in 3 kms with no wind and start from about five mile final. Eventually the spooking causing the by PIO will stop.

[Sidestick_n_Rudder]

Thanks for advice Gents, I will try that on my next sim. Glad to hear that the real a/c is better :)

@Centaurus - yes, the setup was night time/non-prec wx with no visible horizon and little external references (couple of city lights and that was it). Perhaps not the best setup for practicing first landings in a new type....

The instructor did just what you suggested - let me try a couple of times and finally I managed to get a half decent landing, or two, but still not really feeling comfortable with it...

[Uplinker]

You always have a horizon - on the PFD. Even on a visual approach, you will be glancing at the PFD regularly to check your speed, V/S, etc.

In relatively stable conditions, don't ever hold the side-stick over* Operate the side-stick in a "digital" way by inputting nudges lasting less than a second, and after each nudge let the stick return to centre.

nudge - release
nudge - release
nudge - release

If a single quick nudge is not sufficient, instead of holding the input for longer, input two nudges, nudge - centre - nudge.

So most of the time - in stable conditions - the stick is in the centre and you give it a continuous series of very brief "nudge - release's".

Remember, the FBW is correcting for uspets all the time, so all you need to do is just nudge the datum back to the original attitude if it has been disturbed. When flying manually remember that the FBW is still in - a bit like an autopilot, so you have to work with it not against it.

* In very gusty conditions however, you WILL need to hold the stick over, for example when picking up a wing drop. In this situation, FBW is very disconcerting when you are new to it. If a wing has dropped say 20 degrees, you will need more than a nudge to correct it - FBW will not correct large disturbances. You will need to input and hold full roll command to pick it up. Nothing will seem to happen for maybe two seconds, but then it will respond. As SOON as it STARTS to respond and the wing starts coming up, centre the stick again. Don't hold the correction until you have rolled level because then you will massively roll the other way. As soon as the aircraft STARTS to respond to your input, centre the stick - the FBW will do the rest.

So in summary, to avoid PIO's don't hold the stick away from centre for more than a second at a time. Go nudge/centre/nudge/centre/nudge etc. For very large disturbances you might need to hold a full input for a couple of seconds, but release the stick to centre as soon as the aircraft STARTS to respond.

Nobody ever teaches you this which is scandolous, I eventually taught myself after seeing a video of a Tornado jet. The pilot says "coming left xx degrees" and you can see he just goes nudge nudge on the joystick, each nudge-and-and-back-to-centre lasting maybe a third of a second; the aircraft rolls and holds the new datum - he didn't hold the stick over.

I tried this method on the Airbus FBW and it works like a dream.

[Sidestick_n_Rudder]

Gentelmen, thanks for advice.

I tried the above in the sim today and it worked like a treat, even with max crosswind :ok:

Cheers!

SnR

[Fursty Ferret]

- Hold the stick with three fingers. Gripping the stick tightly will almost certainly end in tears.

- Make sure the armrest is at the right height. For me, this is vitally important and probably overlooked. Half a spin on height / angle wheels can be the difference between smooth and jerky flight. If you can get in the sim by yourself for 20 minutes, experiment with the settings. Your forearm *must* be resting on the armrest.

Sim specific stuff: it's supposed to be a collimated display but if you move your head the perspective will change slightly. I can never land on the centre-line in the sim but keeping my head still helps.

Some people advise the "nudge-release" method of sidestick handling. I disagree based on passenger comfort since they'll be throwing up after more than a minute or two of this kind of flying. Smooth and progressive inputs and release them gently, too.

If you've come off a Boeing type you're probably used to applying fairly large and fast roll inputs at low level. This doesn't work on the Airbus.

[Microburst2002]

In the sim, roll is very sluggish. There is a lag between sidestick and roll rate.
In the airplane, roll is very sensitive, it rolls a lot with a very slight input, and it rolls immediately.

[hikoushi]

An alternative way of thinking of the stick is "releasing is trimming". Every time you release sidestick pressure back to center, think of it the same as the gradual releasing of grip pressure on the yoke of a conventional airplane as you trim it out. The effect is obvious in pitch, and if you think of roll as working similarly it feels the same. By using the same rhythm you would use trimming pressures off the yoke of a Boeing, you will naturally operate the side stick smoothly.

Misinterpretation of the "bumping" technique many describe can lead indeed to uncomfortable flying when someone does a bunch of "bumping" back and forth on departure or approach. All you need to do to become a believer is to ride in the aft galley FA jump seat while someone hand flies the aircraft in this manner.

As Bob Buck said, "little pressures, nothing more".

[Uplinker]

@Fursty, you may have misinterpreted my method.

The passengers will be unaware of the nudges, because each one is small and lasts less than a second. The FBW moves its datum fractionally in response to each input, and the flight is very smooth as a result. The point is not to hold the stick over unless you are picking up a big wing drop or similar, and even then, don't hold it over after it has started responding.

The way you hold the stick is a red herring - it is what you do with it that is important (if you will pardon the phrase !!)

I was told to hold it only at the top / hold it only at the base / hold it with two fingers / pretend it's a docker's dick and don't touch it, etc., etc., but nothing worked until I taught myself how to operate with the FBW effectively.

I hold the stick like a pistol grip, which gives me maximum control and feel, and enables me to make very quick inputs, but the really important thing is to make frequent small corrections, and keep returning the stick to neutral in between each one.

As Hikoushi implies, with practice, you will become even smoother on the sidestick.

I have been flying Airbus - including the 330 - for 11 years, and this method most certainly works :ok: