How to fly an A320
Thread Starter
How to fly an A320
My real flying experience ha been purely light aircraft and the occasional glider but I was lucky enough to have a go in an A320 simulator last week. Not full motion, but a proper simulator not a PC based version.
Very interesting and great fun, but on reflection I don't really understand what was going on.
For example, auto throttles meant I had to remember not to adjust the power when putting the nose up or down. But just before touchdown I was told to pull the throttles back to idle and power came down as I would expect. How does the position of the throttle lever influence what the engines actually do? Does it just set the maximum power the auto throttle can set?
Also, I was told not to use the rudders at all in flight. Would this still apply if landing with a crosswind?
Very interesting and great fun, but on reflection I don't really understand what was going on.
For example, auto throttles meant I had to remember not to adjust the power when putting the nose up or down. But just before touchdown I was told to pull the throttles back to idle and power came down as I would expect. How does the position of the throttle lever influence what the engines actually do? Does it just set the maximum power the auto throttle can set?
Also, I was told not to use the rudders at all in flight. Would this still apply if landing with a crosswind?
Search Airbus Autothrust. Loads of discussions on how it works.
https://www.pprune.org/search.php?searchid=15829657
https://www.pprune.org/search.php?searchid=15829657
It sounds like you kind of do understand what was going on. The 'Auto' in autothrottle means it does it for you. Understanding the various modes is complex but in laymans terms you can maneuver with the sidestick and the engine thrust will adjust by itself. In a Boeing the thrust levers move up and down dynamically but on an Airbus they just stay in a detent - the levers don't move but the engine with adjust to keep your speed.
Big jets tend to keep themselves in trim so you don't need the rudders in flight. You generally only use them for maintaining the centreline on takeoff, during an engine failure, to sideslip a crosswind landing and on the rollout.
Big jets tend to keep themselves in trim so you don't need the rudders in flight. You generally only use them for maintaining the centreline on takeoff, during an engine failure, to sideslip a crosswind landing and on the rollout.
My real flying experience ha been purely light aircraft and the occasional glider but I was lucky enough to have a go in an A320 simulator last week. Not full motion, but a proper simulator not a PC based version.
Very interesting and great fun, but on reflection I don't really understand what was going on.
For example, auto throttles meant I had to remember not to adjust the power when putting the nose up or down. But just before touchdown I was told to pull the throttles back to idle and power came down as I would expect. How does the position of the throttle lever influence what the engines actually do? Does it just set the maximum power the auto throttle can set?
Also, I was told not to use the rudders at all in flight. Would this still apply if landing with a crosswind?
Very interesting and great fun, but on reflection I don't really understand what was going on.
For example, auto throttles meant I had to remember not to adjust the power when putting the nose up or down. But just before touchdown I was told to pull the throttles back to idle and power came down as I would expect. How does the position of the throttle lever influence what the engines actually do? Does it just set the maximum power the auto throttle can set?
Also, I was told not to use the rudders at all in flight. Would this still apply if landing with a crosswind?
The OP guessed right; Imagine the thrust levers are transparent ghost levers which move up and down in the range from idle up to wherever you have set the actual levers. On the engine parameters display there are virtual thrust levers drawn on the N1 gauges or EPR gauges, and you can see these lines move according to auto-thrust commands.
The actual physical thrust levers limit the maximum thrust the auto-thrust can command.
In the first forward detent, the maximum thrust available is climb thrust, and this position is used for cruise and intermediate climbs when required.
In the second forward detent, the max thrust is Flex or MCT. Flex is the calculated max thrust needed to take off with the aircraft weight and meteorological conditions on the day, e.g. atmospheric pressure, wind and temperature. Flex is more than climb thrust but less than maximum available thrust, so it saves engine wear and fuel, (and noise levels).
MCT is maximum continuous thrust; normally used if one engine fails and you need maximum thrust on the good engine of a twin that can be sustained safely without a time limit.
The third forward detent is full engine thrust; maximum available thrust in today's conditions, and commonly referred to as TOGA - Take-Off and Go-Around thrust. TOGA thrust is time limited, usually to 10 minutes.
Other aircraft types use various external switches to select these various thrust modes, but Airbus FBW very cleverly and ingeniously combined the thrust mode select switches into the quadrant via a series of detent positions. So to select a particular thrust mode, you simply place the thrust levers into the appropriate detent. This is very intuitive. The levers do not move to indicate the thrust being commanded, but pilots do not need that, they will cross check the engine instruments anyway and will see the virtual thrust lever display telling them what is happening.
At any time, including pilot commanded manual thrust; pushing the levers forward will increase thrust, pulling them back will reduce thrust, so even though the levers don't move by themselves in auto, they still command thrust entirely normally and intuitively, (with a couple of caveats).
For a routine take-off; 50% thrust is set until all engines are stabilised at that thrust, then Flex/MCT is selected by placing the levers into that detent - "click, click". Once airborne and passing the thrust reduction altitude, the levers are pulled back to the CLB (climb) detent, where they stay for the rest of a (normal) flight, until flaring to land.
In some conditions and runway situations, TOGA thrust - "click, click, click" - is used for take-off.
With modern commercial airliners there is a device called a yaw damper which moves the rudder automatically to prevent a situation called Dutch roll, and the yaw damper also applies appropriate rudder movements in turns for turn coordination. So pilots do not need to move the rudder pedals - and shouldn't - unless they are steering along the runway; de-crabbing during a crosswind landing; or compensating for an engine failure during take-off.
The other thing you might have noticed is the Airbus fly-by-wire system. This would take a long post to fully explain, but essentially, the FBW looks at numerous inputs and feed-backs from the airframe as well as the pilot side-stick, and computes flight control surface positions to achieve what is being asked for, (while preventing certain exceedances). The FBW will automatically hold the last attitude commanded - within certain limits - when the side-stick is at neutral, and pilots need to be aware of this, as it needs a different technique to conventional aircraft to fly it properly. But it is not difficult to master.
The little square box on the flight director is the nose of your aircarft. Track and drift are illustrated with various other symbols.
The actual physical thrust levers limit the maximum thrust the auto-thrust can command.
In the first forward detent, the maximum thrust available is climb thrust, and this position is used for cruise and intermediate climbs when required.
In the second forward detent, the max thrust is Flex or MCT. Flex is the calculated max thrust needed to take off with the aircraft weight and meteorological conditions on the day, e.g. atmospheric pressure, wind and temperature. Flex is more than climb thrust but less than maximum available thrust, so it saves engine wear and fuel, (and noise levels).
MCT is maximum continuous thrust; normally used if one engine fails and you need maximum thrust on the good engine of a twin that can be sustained safely without a time limit.
The third forward detent is full engine thrust; maximum available thrust in today's conditions, and commonly referred to as TOGA - Take-Off and Go-Around thrust. TOGA thrust is time limited, usually to 10 minutes.
Other aircraft types use various external switches to select these various thrust modes, but Airbus FBW very cleverly and ingeniously combined the thrust mode select switches into the quadrant via a series of detent positions. So to select a particular thrust mode, you simply place the thrust levers into the appropriate detent. This is very intuitive. The levers do not move to indicate the thrust being commanded, but pilots do not need that, they will cross check the engine instruments anyway and will see the virtual thrust lever display telling them what is happening.
At any time, including pilot commanded manual thrust; pushing the levers forward will increase thrust, pulling them back will reduce thrust, so even though the levers don't move by themselves in auto, they still command thrust entirely normally and intuitively, (with a couple of caveats).
For a routine take-off; 50% thrust is set until all engines are stabilised at that thrust, then Flex/MCT is selected by placing the levers into that detent - "click, click". Once airborne and passing the thrust reduction altitude, the levers are pulled back to the CLB (climb) detent, where they stay for the rest of a (normal) flight, until flaring to land.
In some conditions and runway situations, TOGA thrust - "click, click, click" - is used for take-off.
With modern commercial airliners there is a device called a yaw damper which moves the rudder automatically to prevent a situation called Dutch roll, and the yaw damper also applies appropriate rudder movements in turns for turn coordination. So pilots do not need to move the rudder pedals - and shouldn't - unless they are steering along the runway; de-crabbing during a crosswind landing; or compensating for an engine failure during take-off.
The other thing you might have noticed is the Airbus fly-by-wire system. This would take a long post to fully explain, but essentially, the FBW looks at numerous inputs and feed-backs from the airframe as well as the pilot side-stick, and computes flight control surface positions to achieve what is being asked for, (while preventing certain exceedances). The FBW will automatically hold the last attitude commanded - within certain limits - when the side-stick is at neutral, and pilots need to be aware of this, as it needs a different technique to conventional aircraft to fly it properly. But it is not difficult to master.
The little square box on the flight director is the nose of your aircarft. Track and drift are illustrated with various other symbols.
...The FBW will automatically hold the last attitude commanded - within certain limits - when the side-stick is at neutral, and pilots need to be aware of this, as it needs a different technique to conventional aircraft to fly it properly. But it is not difficult to master.
Basically, yes, (although not immediately during rotation - there is a transition from Direct law to Normal law). And the fact that the FBW does this even when flying manually with the auto-pilot disengaged, is a major point to understand.
Broadly speaking, it "stays where you put it", and auto-trims. However, it won't hold all attitudes - only attitudes within certain sensible flying limits.
But if the flight path is disturbed by wind or turbulence, the attitude will not adjust to recover the flight path; the pilot or the auto-pilot will need to do that, depending who is controlling the 'plane.
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Broadly speaking, it "stays where you put it", and auto-trims. However, it won't hold all attitudes - only attitudes within certain sensible flying limits.
But if the flight path is disturbed by wind or turbulence, the attitude will not adjust to recover the flight path; the pilot or the auto-pilot will need to do that, depending who is controlling the 'plane.
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Last edited by Uplinker; 14th Mar 2024 at 11:43. Reason: clarification
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Why is there a difference in high speed and low speed regime (normal law)?
low=stick commands pitch rate. stick in zero means pitch remains where it is. Flight trajectory not guaranteed
high= stick commands g load. stick in zero means 1g load, Vertical speed remains where it is. Flight trajectory is "guaranteed"
low=stick commands pitch rate. stick in zero means pitch remains where it is. Flight trajectory not guaranteed
high= stick commands g load. stick in zero means 1g load, Vertical speed remains where it is. Flight trajectory is "guaranteed"
In large transport category aircraft you don’t “fly” the plane, you manage the flight.
I consciously move my feet from the rudder pedals to flat on the floor if we climb past 10,000’ as above that altitude the airplane accelerates to its best clean climb speed which despite the software protections can take your tail off if the rudder is mishandled.
You manage the aircraft and its automation and you instruct it what to do.
You don’t actually ‘physically’ fly the aircraft but for maybe 10-20 minutes every flight if that much.
By the way I fly a Boeing
who made their best aircraft before MCDonalds & Douglas took over.
I consciously move my feet from the rudder pedals to flat on the floor if we climb past 10,000’ as above that altitude the airplane accelerates to its best clean climb speed which despite the software protections can take your tail off if the rudder is mishandled.
You manage the aircraft and its automation and you instruct it what to do.
You don’t actually ‘physically’ fly the aircraft but for maybe 10-20 minutes every flight if that much.
By the way I fly a Boeing
who made their best aircraft before MCDonalds & Douglas took over.Is the reason to keep pilots in contact with basic flying?
Last edited by waito; 26th Jun 2024 at 13:28. Reason: more detailled background
When the statement is made that pilots no longer "fly" the aircraft they often mean that they are no longer physically connected to the control surfaces. I think that using your brain to make sense of inputs from the eyes and translate that information into muscle movement that affects the extremities of the body such that those inputs are maneuvering the aircraft still fits the definition of flying. Its still the same result if you get it wrong and the inputs and outputs stop being coordinated. So using my definition it is very important to stay current with those flying skills as you never know when you might need them in real life as yo will definitely have to demonstrate your abilities in the sim.
The pilot inputs are filtered by a computer meaning you have so called protections to keep the airplane safe all times all and rudder deflections optimised. Alpha floor protection will keep you from flying too slow by adding thrust before a stall or turns remain limited to the bank angle you commanded without slowly becoming steeper like in a glider for example. Even with the computer working in the background you can fly an Airbus just like a Cessna and even use manual thrust.
or turns remain limited to the bank angle you commanded without slowly becoming steeper like in a glider for example. Even with the computer working in the background you can fly an Airbus just like a Cessna and even use manual thrust.
Not that it makes a huge difference, but there is one.
So whats the answer to my question?
Why is there a difference in high speed and low speed regime (normal law)?
low=stick commands pitch rate. stick in zero means pitch remains where it is. Flight trajectory not guaranteed
high= stick commands g load. stick in zero means 1g load, Vertical speed remains where it is. Flight trajectory is "guaranteed"
low=stick commands pitch rate. stick in zero means pitch remains where it is. Flight trajectory not guaranteed
high= stick commands g load. stick in zero means 1g load, Vertical speed remains where it is. Flight trajectory is "guaranteed"
meanwhile I read the changeover at ~210KT on A320
Im not sure what you are asking but in both low and high speed protections the flight control computer will make sure that the inputs you are applying will not lead to something nasty happening. So in the low speed protection it will put forward inputs to reduce the AoA and with high speed protection it will raise the nose to reduce the speed. A very simple explanation as there are more things going on but in both cases the "flight trajectory" is simply being put back into the normal flight regime despite the best efforts of a ham fisted pilot.
Here is a classic example of why I love Pprune so much. Members happy to explain things and in a way which even dimwits like me can understand.
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