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OmniAtlas

I can't stall the Airbus

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Running the Airbus 320 here - when speed drops, and the aircraft is out of its speed envelopes (and whatever 'law' the aircraft is now operating in) autothrust/a floor will automatically kicks in. No matter how high I pitch the aircraft, the plane just does not want to stall...talk about thinking on its own :)

 

Is there a way to disable the autothrust?

 

FYI -- I am reading the Airfrance report now; fascinated by how complex and completely different the aircraft operates compared to the Boeings.


Soarbywire - Avionics Engineering

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To disable alpha floor the easiest way is to switch FAC 1+2 on the overhead and revert to alternate law

 

FAC 1 is on the left side and FAC2 is on the right of the overhead..

 

You could also hold down the instinctive push buttons on the thrust levers, you have to hold them for 15 seconds then the auto thrust will be permanently disabled.

 

All depends if it's modelled or not in your addon, it's not in the wilco or AXE

 

Regards


Rob Prest

 

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Ah ok. Will check out the overhead.

 

I haven't read the full report yet.

 

Wasn't N1 at 50% when the aircraft went down?


Soarbywire - Avionics Engineering

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Ah ok. Will check out the overhead.

 

I haven't read the full report yet.

 

Wasn't N1 at 50% when the aircraft went down?

 

It gets a bit deeper then that.


Rob Prest

 

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Can't stall the Airbus? Easy solution - ask any Air France pilot... ^_^

:LMAO:

Howard
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My FlightSim YouTube Channel: https://www.youtube.com/@skyhigh776

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How does an aircraft (not only an airbus) know it is about to stall?

 

Are there parameters (angle of attack, rate of descent/climb, speed) that are computed into the plane and when it reaches outside these flight envelope it signals a stall alarm?

 

How about similar GA aircraft? I know weight will play a role in the calculations, but we don't have a CDU on board; are the parameters simply 'hard-wired'?

 

Thanks.


Soarbywire - Avionics Engineering

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To disable alpha floor the easiest way is to switch FAC 1+2 on the overhead and revert to alternate law

 

FAC 1 is on the left side and FAC2 is on the right of the overhead..

 

You could also hold down the instinctive push buttons on the thrust levers, you have to hold them for 15 seconds then the auto thrust will be permanently disabled.

 

All depends if it's modelled or not in your addon, it's not in the wilco or AXE

 

Regards

 

I disabled FAC1 and FAC2 on the overhead but A/Thr still kicks in when my speed drops too low. Still can't stall.


Soarbywire - Avionics Engineering

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That should have disabled your protections and put you in alt law, you should have also lost the speed trend on the PFD along with limitations like Vls, green dot, S speeds, Alpha max etc

 

If your flying an IAE variant you could try switching to N1 mode (right side overhead) near the manual start switches, that will also disable alpha floor. Are you flying the wilco or Aerosoft bus? As mentioned it is not modelled in those addons.


Rob Prest

 

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How does an aircraft (not only an airbus) know it is about to stall?

 

Are there parameters (angle of attack, rate of descent/climb, speed) that are computed into the plane and when it reaches outside these flight envelope it signals a stall alarm?

 

How about similar GA aircraft? I know weight will play a role in the calculations, but we don't have a CDU on board; are the parameters simply 'hard-wired'?

 

Thanks.

 

The stick shacker A stick shaker is a mechanical device to rapidly and noisily vibrate the control yoke (the "stick") of an aircraft to warn the pilot of an imminent stall. WIKI

 

 

You will get a stall alarm too.

 

Is the fly by wire in the airplane help to stop the plane stall?

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The stick shacker A stick shaker is a mechanical device to rapidly and noisily vibrate the control yoke (the "stick") of an aircraft to warn the pilot of an imminent stall. WIKI

 

 

You will get a stall alarm too.

 

Is the fly by wire in the airplane help to stop the plane stall?

 

I know theres a stick shaker on the airbuses and boeings because they may not 'buffet'. My question is how do the systems *know* you are about to enter a stall.

 

When the systems know, then they activate the stick shaker.

 

 

If your flying an IAE variant you could try switching to N1 mode (right side overhead) near the manual start switches, that will also disable alpha floor. Are you flying the wilco or Aerosoft bus? As mentioned it is not modelled in those addons.

 

Aerosoft. Sorry missed your last sentence.


Soarbywire - Avionics Engineering

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When the systems know, then they activate the stick shaker.

 

A stick pusher is a device installed in some fixed-wing aircraft to prevent the aircraft from entering an aerodynamic stall. Some large fixed-wing aircraft display poor post-stall handling characteristics or are vulnerable to deep stall. To prevent such an aircraft approaching the stall the aircraft designer may install a hydraulic or electro-mechanical device that pushes forward on the elevator control system whenever the aircraft’s angle of attack reaches the pre-determined value, and then ceases to push when the angle of attack falls sufficiently. A system for this purpose is known as a stick pusher.

The safety requirements applicable to fixed-wing aircraft in the transport category, and also to many military aircraft, are very demanding in the area of pre-stall handling qualities and stall recovery. Some of these aircraft are unable to comply with these safety requirements relying solely on the natural aerodynamic qualities of the aircraft. In order to comply with the requirements aircraft designers may install a system that will constantly monitor the critical parameters and will automatically activate to reduce the angle of attack when necessary to avoid a stall. The critical parameters include the angle of attack, airspeed, wing flap setting and load factor. Action by the pilot is not required to recognise the problem or react to it.

Aircraft designers who install stick pushers recognise that there is the risk that a stick pusher may activate erroneously when not required to do so. The designer must make provision for the flight crew to deal with unwanted activation of a stick pusher. In some aircraft equipped with stick pushers, the stick pusher can be overpowered by the pilot. In other aircraft, the stick pusher system can be manually disabled by the pilot.

Stick pushers should not be confused with stick shakers. A stick shaker is a stall warning device whereas a stick pusher is a stall avoidance device.

 

WIKI

 

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