ailerons or rudder for crabbing on the Fenix A320

[SquadronLeader 63]

When flying the Fenix A320 on autopilot with a strong cross wind, the plane points into the cross wind and 'crabs' along. Is it the ailerons or the rudder that the autopilot uses to achieve this? - and which should I use if I disconnected the autopilot and flew manually? 

[jcomm 6,081]

If you disconnect the AP the airbus, just as most other aircraft, will "auto-crab" into the wind...

If there are gusts/shear/turbulence you might have to input some aileron to compensate for some unwanted bank, but otherwise no need for that...

Just before touchdown, bellow 50' you're in Flare Mode, so, if you want to uncrab you use rudder only, while on non-fbw aircraft you may need to use cross-controls.

After contacting the ground you're in Ground Mode, so you may need to input sidestick roll to counter the effects of a strong x-wind too because in Ground Mode there's a direct proportional relationship between the sidestick deflection and deflection of the flight controls, and it's no longer roll rate that is commanded...

Now the truth....: Some of my fellow soaring chaps are also Airbus drivers, and some tell me - "José ... forget about that FBW doctrine,,, I fly the Airbus under x-wind landings just as I did every other aircraft I flew before"

This always leaves me confuse... and I honestly don't recall what I used in the TAP LevelD A320 session around 20 yrs ago 😕

Edited November 8, 2022 by jcomm

[Fiorentoni 4,479]

7 minutes ago, SquadronLeader said:

When flying the Fenix A320 on autopilot with a strong cross wind, the plane points into the cross wind and 'crabs' along. Is it the ailerons or the rudder that the autopilot uses to achieve this? - and which should I use if I disconnected the autopilot and flew manually? 

The aircraft just flies a different heading (like 3 degrees right of the runway heading) to compensate for the wind, it does not hold the rudder to sideslip or something like that. You do the same when you fly manually, i.e. just follow the flight director.
The rudder you only use to de-crab during the flare.

[Sceadu 117]

As Fiorenti said above.

Basically assuming you know how to point the nose in a given direction and keep the wings level, then you simply point the nose in a direction that results in the required ground track, you can make it sound mor complicated but it isnt

de crab in the flare by using out of wind rudder and some into wind aileron to keep the wing from lifting

 

 

Edited November 8, 2022 by Sceadu
speeling (again)

[hvw 418]

You may want to take a look at this, a tutorial by a real-world A320 pilot:

 

 

 

[jcomm 6,081]

And... this is probably why my fellow Airbus drivers say it's the same as in any other airliner...

Cross - wind take - off and landing on a Airbus A320. Baltic Aviation Academy - YouTube

[ahsmatt7 1,213]

You don’t ever touch the rudder in these transport category aircraft until you are in the flare.  You don’t need to when you are on approach or climb or descend or cruise. That’s why there’s a yaw damper.

 

Edited November 9, 2022 by ahsmatt7

[jcomm 6,081]

2 minutes ago, ahsmatt7 said:

You don’t ever touch the rudder in these transport category aircraft. You don’t need to. That’s why there’s a yaw damper.

You surely have to ... in the airbus and some other fbw aircraft  on the blend between Nornal to Flare and then Ground mode...

On pretty much all other fixed wing aircraft to uncrab, most of the time added by aileron into the wind...

 

[SAS443 1,749]

1 hour ago, jcomm said:

You surely have to ... in the airbus and some other fbw aircraft  on the blend between Nornal to Flare and then Ground mode...

On pretty much all other fixed wing aircraft to uncrab, most of the time added by aileron into the wind...

 

Read the OP, very carefully 😉

On 11/8/2022 at 9:56 AM, SquadronLeader said:

When flying the Fenix A320 on autopilot with a strong cross wind, the plane points into the cross wind and 'crabs' along. Is it the ailerons or the rudder that the autopilot uses to achieve this? - and which should I use if I disconnected the autopilot and flew manually? 

 

[jcomm 6,081]

4 minutes ago, SAS443 said:

Read the OP, very carefully 😉

 

Ah ok, if it was meant to directly answer the OP, then I fully agree... Actually that's what I wrote as well 🙂

 

[Bobsk8 12,959]

The main difference between any small GA aircraft and aircraft like the Airbus, is when you flare, on smaller aircraft you use rudder to align with the runway, and aileron to keep you centered on the runway. ( Wheel for the wind, rudder for the runway is what I was taught.)  On large transport aircraft, you don't use much aileron, because you don't want the engines scraping the runway, so you basically just keep the wings level during the flare and kick out the crab with the rudder. 

[ahsmatt7 1,213]

2 hours ago, jcomm said:

You surely have to ... in the airbus and some other fbw aircraft  on the blend between Nornal to Flare and then Ground mode...

On pretty much all other fixed wing aircraft to uncrab, most of the time added by aileron into the wind...

 

You’re quick. I edited the post the second after I posted it.