Does the FBW pitch down when flaring?

[Mikii 19]

Hi guys!

I noticed something weird today.

When I flare the airbus the FBW always goes against me. I saw this on other topics and it looks like it is not normal.

It is very hard to describe but I try:

I know the A320's FBW needs strong inputs, particularly on landing. But in my case when I start flaring I notice that everything is OK until there is a strange reaction (at about 20 ft AGL) pulling the nose of the aircraft down (I know aerodynamics and this is a very rough reaction, not natural). As a consequence the plane hits the ground rather violently (I record about -450ft/min at touchdowns).

I don't know if I make myself clear but I hope someone could help me and resolve the problem.

BTW thanks and CONGRATULATIONS to Aerosoft dev team for their work, this aircraft is great and getting better and better with each update.

Michael (AXE v 1.04 and hotfix 12).

PS: Maybe I can try to record a small video showing you the thing

[--- 170]

The 'real' Airbus does introduce a nose down pitch attitude at 30ft. If you wouldn't pull back on the sidestick the attitude would reach -2deg after 8sec. On the AXE this feature has been correctly implemented, although the effect is just a tiny bit too strong IMO.

[Alexpdv 35]

Yes, it's the so called "Flare Mode" which was designed to allow for a conventional flare manouver during landing, it activates as the aircraft passes 50 ft RA during landing.

The system memorizes the a/c pitch attitude at 50 ft RA, this attitude becomes the reference point for pitch control. The sidestick changes from load factor demand, to delta-pitch demand. This means that the sidestick commands a certain number of degrees nose up or nose down relative to the reference pitch. If the pilot lets go of the stick, the aircraft returns to the reference pitch attitude.

As the aircraft passes 30 ft RA, the system begins gradually reducing the reference pitch attitude to 2 degrees nose down over a period of 8 seconds, thus requiring the pilot to apply slight back pressure on the sidestick to flare the aircraft.

Hope this helps

[Mikii 19]

Ok thank you for the technical info.

Didn't know that it was a feature of the real A320.

Please mark as solved!

[alaaar 23]

Hi and sorry to jump in the post, however, I have a question that might be related, I only manually land the plane, I rarely use auto-landing, the issue is more obvious with A320 more than A321.... what I noticed - and it could be entirely different subject- is that if VREF is about 145.....the plane will be under control fully with in - 5knts of the VREF, if speed drops more (but still higher that minimum maneuver speed and of course minimum speed "stall") it will lose lift and head to the ground with no use to increase the pitch ......the only recovery from that is to increase the throttle dramatically, this will save the day but most probably will cause overshooting the runway landing zone which could cause a problem with shorter runway.

I am not of course a real pilot ......I am comparing with similar size plane, a Boeing and a top quality developer, in this case the plane is reacting normally as long as you didn't get into the amber or red/black zone on the speed indications.

Is the plane behavioral in normal ? perhaps airbus is somehow different ? thanks

[--- 170]

I guess you mean V_LS. This is the absolute minimum approach speed if you fly without A/THR.

Normally you fly 5-10kts faster. If you really fly that slow you need to keep the thrust well into the flare and the pitch down at 30ft will be rather strong, but there shouldn't be any sudden loss of lift below that speed.

Another 5kts (and even slower) less is only acceptable in the final stages of the flare.

The strong nose down moment and the reduction in pitch authority might cause the illusion of a 'loss of lift'.

[alaaar 23]

Thanks Major

[Guest]

^{I, also have problems with flare. The ac seems controlled, during the approach but whatever i do, at 20 fts aprox, the ac falls like a brick.}

^{Have you revised this in the upcoming SP1 or this behaviour is like the real one?}

^{Thanks in advance.}

^Miquel.

[KyleD 1027]

^{I, also have problems with flare. The ac seems controlled, during the approach but whatever i do, at 20 fts aprox, the ac falls like a brick.}

^{Have you revised this in the upcoming SP1 or this behaviour is like the real one?}

^{Thanks in advance.}

^Miquel.

Hi Miquel,

This thread got a little lost towards the end, but the second post here is your answer:

The 'real' Airbus does introduce a nose down pitch attitude at 30ft. If you wouldn't pull back on the sidestick the attitude would reach -2deg after 8sec. On the AXE this feature has been correctly implemented, although the effect is just a tiny bit too strong IMO.