A320 : centerline correction in very short final

[tolosan]

Anyone using rudder inputs ?

[tubby linton]

I always found that using the rudder was a bad idea as it induces a roll which the fbw tries to compensate and causes more trouble than it is worth.

[Sprinkles]

Define very short final.

Not trying to be cocky but I always use the rudders in the flare with a cross wind.

I'm not conscious of using them above 30 feet. The side stick seems to do a pretty good job of pointing the jet in the general direction of the tarmac in my experience (RHS & 2/3rds crosswind limit).

The rudder simply tidies the important bit up. :E

[WhyByFlier]

Either continue the landing and correct on the ground or go around and try again. Don't start playing with the rudder in flight on a big boy. We all land slightly off the centreline now and then. It really depends why you're off the centreline too.

It's like people who try and correct for the centreline on an engine failure on take off - it's not a requirement - just keep it straight!

One thing that confuses me on these types of questions - why don't you ask the captains you fly with what they'd do? What they'd like you to do? What they'd have done on your approach etc.

[ZeBedie]

Rudder will change where you're pointing, but not where you're going. Pointless, messy and plain wrong.

[Stroyee]

Hi Tolosan,

Yes, sometimes i use rudder input for crosswind landing. There is a complete explanation in the FCOM, FCB-FCB 25 Use of Rudder on Transport Category Airplanes.

[Rick777]

When you are below 50 feet and in the land mode rudder works just like a normal airplane. Above that you are just fighting with the computers.

[tolosan]

Thanks to all, special thanks for Stroyee for the reference.

FCB-FCB24 about Aircraft handling in final approach is also helpful.

[paddy_22002]

Always use it in a crosswind, last 10' or so. Squeeze off the drift and cross control. Basically the same technique with all the large jets I've flown. The only one I remember it wasn't recommended was the 747 on a wet runway.
However watching some of the max x-wind limited videos it would seem perfectly safe, although uncomfortable to just slam it on with the drift on.

[WhyByFlier]

When you are below 50 feet and in the land mode rudder works just like a normal airplane. Above that you are just fighting with the computers.


Is incorrect - the lateral and pitch channels are seperate. The lateral mode remains in 'flight' mode until on the ground.

See FCOM DSC 27-20 Flight Controls:

When the aircraft is on the ground (in “on ground” mode), the sidestick commands the aileron and roll spoiler surface deflection. The amount of control surface deflection that results from a given amount of sidestick deflection depends upon aircraft speed. The pedals control rudder deflection through a direct mechanical linkage. The aircraft smoothly transitions to “in flight” mode shortly after liftoff.
When the aircraft is in the “in flight” mode, normal law combines control of the ailerons, spoilers (except N° 1 spoilers), and rudder (for turn coordination) in the sidestick. While the system thereby gives the pilot control of the roll and heading, it also limits the roll rate and bank angle, coordinates the turns, and damps the dutch roll.
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.
When the aircraft is in “flare” mode, the lateral control is the same as in “in flight” mode.
After touchdown, the aircraft smoothly transitions from “in flight” mode to “ground” mode.

[Cough]

Being picky - The rudder always works like any other aircraft. Its what the rest of the controls do which makes it a little different. I agree about the sidestick lateral control though!

[vilas]

You do not use rudder in Airbus for lateral control unless with OEI or failure of other flight control, for removing crab after flare or on ground during takeoff and landing roll, if you are not aligned below 500ft visual you are unstable you go around.

[Bengerman]

Advice from Airbus is to treat it like an aircraft! (Yes, I know!!)

In a crosswind they recommend the crab approach until in the flare at which point, align the aircraft with the runway centreline using rudder and use aileron to maintain centreline.

Land.

Feels sort of familiar!