Airbus hand-flying characteristics

[Chris Scott]

SIDESTICK

hikoushi,

You will have a lot of fun on the A330, and there's a lot of good stuff here. I don't know what Iver's problem is with the FMS part of the FMGS (or even if he is a user of it), but I must correct any false impressions you may have gleaned from the YouTube video he recommends.

The video itself is great; handling of the sidestick poor by both PFs. It's a tribute to the FBW system that stirring the pudding to that extent does not produce PIO.

In the case of the L/H seat PF, three faults are evident.
1) The stick is never stationary in the neutral position (which it should be much of the time, even when manoeuvring). It's always on the move.
2) He constantly holds the stick in his hand, instead of using fingers and thumb.
3) His armrest is so badly positioned (too low, and wrong rake-angle) that he is unable to rest his forearm on it. (See the landing approach at the two-minute point on the video.) As a result of this and (2), his whole forearm moves back and forth, unsupported, during pitch commands.

It's very important first to adjust the armrest to the best graduations of height and angle that suit your arm. These can be quickly established during type conversion. The best way to operate the sidestick is to rest your elbow stationary on the armrest so that your open hand surrounds the top of the stick without touching it. Your wrist should be clear of the armrest at all times while you are controlling the stick, so that your hand movements are unimpeded. Your fingers will be on the outside of the stick; your thumb on the inside of it.

The following description of how to control the stick assumes you are in the L/H seat, the R/H seat obviously being a mirror-image of the left (I had to maintain currency in both). Remember: your elbow should not move.

Use your thumb to move the stick to the left, and to move it forwards. The transition from one action to the other is achieved by twisting your wrist through about 90 degrees. Diagonal movements (forward-left) are achieved with the wrist somewhere between the two extremes.

Use your fingers (as many as you like) to move the stick to the right, and to move it backwards. The transition from one action to the other does not require as much of a twist of the wrist as with the thumb action.

Someone said recently on the Airbus FBW thread that stick commands should be small, but long-lasting. I partly disagree. The only long-lasting commands I can think of are to rotate the a/c on take-off or go-around, and rolling it from a turn one way into a turn the other way. Landing flare is comparatively brief. *** There are no hard and fast rules, but normal commands are small-to-medium jabs, their effects limited by short duration. Between each jab, the stick should be allowed to return to and remain in neutral while - with your hand relaxed - you observe the effect of the command.

So how to fly the Airbus FBW manually? I'm not going to try and discuss C* in this post (and others are currently doing that). But I can offer a flavour of what it's like, from a pilot's perspective. Five years ago, during PPRuNe discussions on an A320 crosswind incident at Hamburg, I wrote and amended this, which may be of some (unofficial) interest:

http://www.pprune.org/tech-log/31609...ml#post3956007

On the general subject of how the sidestick is often misused, I offered this:

http://www.pprune.org/tech-log/31609...ml#post3979423

Disclaimer: Although I flew the A320 for 14 years, I retired at the end of 2001; so am way out of date. Anyway, I hope this helps.

*** [EDIT] This is correct in terms of the time taken to rotate the a/c by only about 3 degrees. However, it overlooks the effect of Landing Mode, which - below a certain height (30ft in my 1988 FCOM) - requires the PF to pull the stick progressively backwards: even to maintain a steady pitch-attitude. This feature goes some way to simulate the stick load on landing with traditional controls. Without Landing Mode, it would be easy to over-flare.