Thread: Airbus Type Controls
01-14-2007, 11:00 PM #1
Airbus Type Controls
Can anyone explain to me what the effect of the "Airbus Type Controls" is? What is the philosophy within that? (Airbus FCU)
01-15-2007, 01:50 AM #2
Airbus Type Controls
What do you mean By Airbus Type controls???
01-15-2007, 03:27 AM #3
- Join Date
- Oct 2005
- Gold Coast-AUSTRALIA
I think this is what he is referring to:
/ This setting will make the FCU
/ control pitch and bank as is done
/ on with the Airbus sidestick, i.e.
/ the current pitch and bank will
/ be maintained and sidestick deflection
/ increases/decreases it. The aircraft
/ does not level out by itself.
01-15-2007, 07:24 AM #4
- Join Date
- Jan 2007
I know only little about airbus system. But from what you quoted, the AirbusTypeControls sounds like CWS on 737NG. Is it correct???
01-15-2007, 10:01 AM #5
- Join Date
- Oct 2005
- Holley, New York U.S.A.
No... what this does is when you start a turn in the AB, if you let the stick return to center, the aircraft does not stop the turn. You have to manualy stop the turn with input. so if you start a 10deg bank it will stay at 10deg untill you stop it. Hope this helps.Bob Reed
01-15-2007, 01:23 PM #6
Is this how the airplane reacts to sidestick inputs in the bus? I've tried it out, and the effect is an extremely low senstitive reaction to joystick inputs.
How is this turned on/off in the real thing? Via the flight computers (flight envelope) or something similar?
01-16-2007, 02:22 AM #7
- Join Date
- Jan 2007
From what you wrote, the Airbus control seems really like the way CWS work in NG except the 737's control wheel will stay displaced from neutral when release. I am no expert of both type. I only read the manual and try in PMDG737 in FS. When CWS activate, moving the yoke to any flight path angle, it will stay there until the crew return it to normal.
Anyone can explain the difference of these two systems further please??
This is quoted from the NG manual:
Autopilot Control Wheel Steering
With CWS engaged, the A/P maneuvers the airplane in response to control pressures applied by either pilot. The control pressure is slightly higher to that required for manual flight. When control pressure is released, the A/P holds existing pitch attitude and bank angle.
If aileron pressure is released with 6 degrees or less bank, the A/P rolls the wings level and holds existing heading.
This heading hold feature with a bank angle of less than 6 degrees is inhibited and A/P will maintain present bank angle, when any of the following conditions exist:
- below 1,500 feet RA with the landing gear down,
- after F/D VOR capture with TAS 250 knots or less,
- after F/D LOC capture in the APP mode.
06-09-2009, 07:26 PM #8
So how does B737NG reacts flying full manual because i noted today that my yoke is working like the Airbus after adjusting some axis using FSUIPC and don't remember if it was working as it is until now, so someone knows where can i change this setting if there is one?
i.e when i turn my yoke for example to a turn of 20 degrees to the left, the plane stays turning in that angle and my yoke is neutral position, so it doesn't return together with the yoke movement to neutral...Cockpit NG Simulation
Facebook Page: https://www.facebook.com/cockpitngsimulation/
06-10-2009, 03:14 AM #9
the airbus type control flag was to activate the first attempts to implement FBW in the airbus suite of project magenta. FBW is fly-by-wire system. Roberto Soriano can elaborate much more on this I guess. But as far as I know FBW is a gathering of different functions. First of all the pilot is telling the flight computers what flight path he wants by giving instructions via the sidestick. So if he pulls back a little on the sidestick he indicates a pitch increase and the speed to change the pitch is related to the amount of movement of the sidestick. Same applies for bank. Normally when banking the plane will loose altitude and the pilot needs to apply also a little pitch up to compensate this. In the FBW system the plane will do this on his own, so when a sidestick is pushed sideways, the plane will bank and not loose any altitude, no need to pull the stick back a little. When releassing the stick the current attitude of the plane will be help. So when setting the bank angle to 20 degrees and releasing the stick back to neutral... the plane will remain in a continuous circle at the same altitude and with the same bank angle except when 33 degrees is passed, when releasing the stick the plane will come back to 33 degrees. Also at 67 degrees the plane will stop banking even the sidestick is pushed to go over the 67 degrees.
Same applies for pitch protection but here i am not sure about the pitch angle values. I think it was like -15 degrees and 30 degrees. And I think these values even depend on hte flaps/slats config.
Also part of the FBS is the overspeed protectoin and the alfa floor protection (stall protection).
This system is pretty good implemented by FS communicator. Some of us are using this in there airbus home cockpits but its requires a lot of tuning and a mail to the developper to get it ... normally he took it of the market (reason was that som previous version was hacked and put for download on the internet..shame on the them). He wasnt asking too much money for it and was very usefull in times of epic ... now its still usefull for the FBW implementation.
Also AST is working on it but someone posted something about it on their forum and it was deleted by the staff since they agreed with the testers not to discuss PRO features on the public forum. This indicates to me that this will be only for PRO users, not the advanced users.
On pm I tried to activate it was had to remove it again since i could not control the plane nicely.
My 2 cents ... PeterFS9+PM+AST+opencockpits
06-10-2009, 03:46 AM #10
- Join Date
- Nov 2005
- Vancouver BC Canada
Very well explained Peter and definitely Roberto Dodiano being an airbus F/O certainly is better qualified. Airbus type controls as you call it and as peter explained are based on FBW technology. Airbus uses a series of what is refered to as airbus Laws to explain the full operation of the Airbus operation.
Becomes active shortly after takeoff and remains active until shortly before touchdown.
Sidestick deflection and load factor imposed on the aircraft are directly proportional, regardless of airspeed.
With sidestick neutral and wings level, system maintains a 1 g load in pitch.
No requirement to change pitch trim for changes in airspeed, configuration, or bank up to 33 degrees.
At full aft/fwd sidestick deflection system maintains maximum load factor for flap position.
Sidestick roll input commands a roll rate request.
Roll rate is independent of airspeed.
A given sidestick deflection always results in the same roll rate response.
Turn coordination and yaw damping are computed by the ELACs and transmitted to the FACs.
No rudder pedal feedback for the yaw damping and turn coordination functions.
Transition to flare mode occurs at 50' RA during landing.
System memorizes pitch attitude at 50' and begins to progressively reduce pitch, forcing pilot to flare the aircraft
In the event of a go-around, transition to flight mode occurs again at 50' RA.
Protections Load factor Limitation
Prevents pilot from overstressing the aircraft even if full sidestick deflections are applied.
Pitch limited to 30 deg up, 15 deg down, and 67 deg of bank.
These limits are indicated by green = signs on the PFD.
Bank angles in excess of 33 deg require constant sidestick input.
If input is released the aircraft returns to and maintains 33 deg of bank.
High Angle of Attack Protection (alpha):
When alpha exceeds alpha prot, elevator control switches to alpha protection mode in which angle of attack is proportional to sidestick deflection.
Alpha max will not be exceeded even if the pilot applies full aft deflection
High Speed Protection:
Prevents exceeding VMO or MMO by introducing a pitch up load factor demand.
The pilot can NOT override the pitch up command.
Low Energy Warning:
Available in CONF 2,3, or FULL between 100' and 2,000' RA when TOGA not selected.
Produces aural "SPEED SPEED SPEED" when change in flight path alone is insufficient to regain a positive flight path (Thrust must be increased).
but in the event of some sort of unusual action as described below the airbus will then revert to :
In pitch alternate law the flight mode is a load factor demand law similar to the Normal Law flight mode, with reduced protections.
Pitch alternate law degrades to pitch direct law when the landing gear is extended to provide feel for flare and landing, since there is no flare mode when pitch normal law is lost.
Automatic pitch trim and yaw damping (with limited authority) is available.
Turn coordination is lost.
When pitch law degrades from normal law, roll degrades to Direct Law - roll rate depends on airspeed.
Protections All protections except for load factor maneuvering protection are lost.
The load factor limitation is similar to to that under Normal Law.
Amber XX's replace the green = attitude limits on the PFD.
A low speed stability function replaces the normal angle-of-attack protection
System introduces a progressive nose down command which attempts to prevent the speed from decaying further.
This command CAN be overridden by sidestick input.
The airplane CAN be stalled in Alternate Law.
An audio stall warning consisting of "crickets" and a "STALL" aural message is activated.
The Alpha Floor function is inoperative.
The PFD airspeed scale is modified:
VLS remains displayed
VALPHA PROT and VALPHA MAX are removed
They are replaced by a red and black barber pole, the top indicating the stall warning speed VSW
A nose up command is introduced any time the airplane exceeds VMO/MMO to keep the speed from increasing further, which CAN be overridden by the sidestick.
Bank angle protection is lost.
Certain failures cause the system to revert to Alternate Law without speed stability.
Yaw damping is lost if the fault is a triple ADR failure.
And then of course if other events come into play the pilot would refer to
ABNORMAL ALTERNATE LAW, DIRECT LAW or MECANICAL BACKUP I will refer you to look these up yourself to better understand them and to save space of my typing them here.
So as you can see the Airbus mode your refering to tends to involve alot more than just mmoving the stick one way orr the other. And again as Peter stated FS Communicator is excellent for helping to make this functin properly.I hope this helped.
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