ALPHA PROT/FLOOR/MAX
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"What do you mean by target speed?"
I mean the speed autothrust will maintain if it is engaged.
"We have to be at 1 at S speed and at 2/3 at F speed? "
No there is no such requirement.
"What is the lowest speed the plane can fly without flaps? VLS?"
In any configuration the lowest speed you should go is Vls. In Conf0,1,2,3,Full, you can go down to Vls. The plane can go slower of course, but this is not ideal (Except in case of Gpws warning or windshear, when you can go below)
"Whats does the amber = mean?"
Those are the VFEnext marks, indicating the speed you must be below in order to increase flap config by 1 stage.
I mean the speed autothrust will maintain if it is engaged.
"We have to be at 1 at S speed and at 2/3 at F speed? "
No there is no such requirement.
"What is the lowest speed the plane can fly without flaps? VLS?"
In any configuration the lowest speed you should go is Vls. In Conf0,1,2,3,Full, you can go down to Vls. The plane can go slower of course, but this is not ideal (Except in case of Gpws warning or windshear, when you can go below)
"Whats does the amber = mean?"
Those are the VFEnext marks, indicating the speed you must be below in order to increase flap config by 1 stage.
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Wow thanks for that document m39462! Very interesting to read.
Seems crazy that in turbulence, as soon as you reach A.prot, even if it just clicks over for a second, the plane will maintain it and zoom climb thousands of feet without any sidestick input!
And with AP engaged, the same happens at A.prot +1° as it then disengages AP and enters AoA protection.
I wonder how many airbus pilots are aware of this? I was not, and I suspect I am not alone.
This could even have some relationship with Air Asias recent crash... turbulence followed by zoom climb...
Seems crazy that in turbulence, as soon as you reach A.prot, even if it just clicks over for a second, the plane will maintain it and zoom climb thousands of feet without any sidestick input!
And with AP engaged, the same happens at A.prot +1° as it then disengages AP and enters AoA protection.
I wonder how many airbus pilots are aware of this? I was not, and I suspect I am not alone.
This could even have some relationship with Air Asias recent crash... turbulence followed by zoom climb...
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I am not able to get you.
1) What is F speed and S speed for landing? You said they were target speeds. Please explain. You mean to say Athr will manage F speed and S speed? What is the relation between Athr and flaps/slats speed????
2) You don't have VFE for take-off?
Thanks
1) What is F speed and S speed for landing? You said they were target speeds. Please explain. You mean to say Athr will manage F speed and S speed? What is the relation between Athr and flaps/slats speed????
2) You don't have VFE for take-off?
Thanks
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Ok so whether you are accelerating or decelerating, you need to know at what speed you can extend or retract one more stage.
If you are accelerating, those speeds are F speed (to conf1) and S speed (to conf0).
If you are decelerating, those speeds are the amber = marks which move down every time you select a new conf.
So to answer your questions...
1. Yes, Athr will maintain F/S/O speed for you, so long as it is engaged, and the approach mode is activated on the fmgs.
O speed (green dot) in Conf0
S speed in conf1
F speed in conf2/3
Approach speed in conf full (Or conf3 if that is landing configuration)
2. Yes of course you have Vfe. It is Vmax, the top red band on the speed tape. Vmax=lowest of Mmo, Vmo, Vle, Vfe.
So you have three speeds relating to the flaps configuration...
1) Vmax, which is your maximum speed for the configuration (=Vfe on approach)
2) amber "=" which is what the Vfe will be if you select one more stage of flaps
3) F/S speed which is the min speed before you can safely retract one stage. (Think of it as roughly where the new Vls is going to be after selecting one stage up)
If you are accelerating, those speeds are F speed (to conf1) and S speed (to conf0).
If you are decelerating, those speeds are the amber = marks which move down every time you select a new conf.
So to answer your questions...
1. Yes, Athr will maintain F/S/O speed for you, so long as it is engaged, and the approach mode is activated on the fmgs.
O speed (green dot) in Conf0
S speed in conf1
F speed in conf2/3
Approach speed in conf full (Or conf3 if that is landing configuration)
2. Yes of course you have Vfe. It is Vmax, the top red band on the speed tape. Vmax=lowest of Mmo, Vmo, Vle, Vfe.
So you have three speeds relating to the flaps configuration...
1) Vmax, which is your maximum speed for the configuration (=Vfe on approach)
2) amber "=" which is what the Vfe will be if you select one more stage of flaps
3) F/S speed which is the min speed before you can safely retract one stage. (Think of it as roughly where the new Vls is going to be after selecting one stage up)
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So while landing, you have to be below the amber = and F speed to retract your flaps?
So when you go to 2, F speed will go down and the amber =. When you will be below the amber =, you can retract your flaps to 1?
Thanks
So when you go to 2, F speed will go down and the amber =. When you will be below the amber =, you can retract your flaps to 1?
Thanks
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Ok.
1) VFE is the maximum speed at which we can fly without braking our flaps/slats. Right?
2) Is F speed for landing a target speed where we have to have our flaps at conf 2/3 or is it the minimum speed at which we can fly without flaps 2/3?
3) Same question for slats.
So when we extend our slats to 1, we can see the amber =
That is the maximum speed we can fly with our slats. Then there is S speed which is.........
Thanks
1) VFE is the maximum speed at which we can fly without braking our flaps/slats. Right?
2) Is F speed for landing a target speed where we have to have our flaps at conf 2/3 or is it the minimum speed at which we can fly without flaps 2/3?
3) Same question for slats.
So when we extend our slats to 1, we can see the amber =
That is the maximum speed we can fly with our slats. Then there is S speed which is.........
Thanks
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"So while landing, you have to be below the amber = and F speed to retract your flaps?"
While on approach you will be extending your flaps. You only have to be below amber =
"So when you go to 2, F speed will go down and the amber =. When you will be below the amber =, you can retract your flaps to 1?"
When you go to 2, F speed is displayed. It doesnt change, but S speed disappears and F speed appears on the speed tape.
Trying to put it anotherway...
To RETRACT flaps you have to be ABOVE F/S speed.
To EXTEND flaps you have to be BELOW amber =.
1. Yes.
2. Neither. It is a comfortable speed to fly with flaps 2/3. And the minimum speed if you want to retract to flaps1.
3. Neither. It is a comfortable speed to fly with flaps 1. And the minimum speed if you want to retract to flaps0.
"So when we extend our slats to 1, we can see the amber =
That is the maximum speed we can fly with our slats. Then there is S speed which is......."
No. with flaps 1, your Vmax is Vfe. The amber = will show the Vfe for flaps2.
While on approach you will be extending your flaps. You only have to be below amber =
"So when you go to 2, F speed will go down and the amber =. When you will be below the amber =, you can retract your flaps to 1?"
When you go to 2, F speed is displayed. It doesnt change, but S speed disappears and F speed appears on the speed tape.
Trying to put it anotherway...
To RETRACT flaps you have to be ABOVE F/S speed.
To EXTEND flaps you have to be BELOW amber =.
1. Yes.
2. Neither. It is a comfortable speed to fly with flaps 2/3. And the minimum speed if you want to retract to flaps1.
3. Neither. It is a comfortable speed to fly with flaps 1. And the minimum speed if you want to retract to flaps0.
"So when we extend our slats to 1, we can see the amber =
That is the maximum speed we can fly with our slats. Then there is S speed which is......."
No. with flaps 1, your Vmax is Vfe. The amber = will show the Vfe for flaps2.
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Reading this thread is giving me a persistent visual of a paraplegic monkey trying to copulate with a pigskin. Possibly even two paraplegic monkeys trying to copulate with the same pigskin. Pretty comical, actually.
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Ok Amadis....hmmm.....
@Dupre: Thanks a lot Dupre!
Ok...so when we see the first amber = it means that we have to extend slats to 1.
Then, the amber = will go down and S speed will come. So it means that it is a comfortable speed to fly. Now, we reach the amber = , we then extend our flaps to 3. We pass F speed which appears. It is a comfortable speed to fly.
1) Am I right?
2) When do we have flaps full?
3) Do we have to be at conf 2 or 3 when we pass our second amber =?
Thanks
@Dupre: Thanks a lot Dupre!
Ok...so when we see the first amber = it means that we have to extend slats to 1.
Then, the amber = will go down and S speed will come. So it means that it is a comfortable speed to fly. Now, we reach the amber = , we then extend our flaps to 3. We pass F speed which appears. It is a comfortable speed to fly.
1) Am I right?
2) When do we have flaps full?
3) Do we have to be at conf 2 or 3 when we pass our second amber =?
Thanks
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Passing an amber = does not mean you have to extend any flaps at all. It just means you can extend flaps if you want to.
Normally approach sequence goes....
1. Activate approach phase. Autothrust decelerates to green dot.
(green dot around 210kt, amber= 230kt on A320)
2. When below amber = select flaps 1. Autothrust decelerates to S speed.
(S speed around 180kt, amber= 200kt on A320).
3. When you are ready for Flaps 2 (typically just before glideslope intercept) select flaps 2. Autothrust decelerates to F speed.
(F speed around 140kt, amber= 185kt on A320)
4. Gear down (exactly when depends on your judgement of a few factors - winds, altitude, speed etc)
5. When you are nearing the point at which you need to be stabilised, select flaps 3. Autothrust keeps maintaining F speed, Amber= moves to 177kt on A320.
6. Very shortly after, select flaps full (if that is landing configuration), Autothrust maintains Vapp (or GSmini if active) and the amber = will disappear as there is no "next flap setting" from flaps full. (you won't see this on the pfd though, as it will be off the upper end of the speed tape)
7. Call for landing checklist.
Amadis - glad you are enjoying the show
Normally approach sequence goes....
1. Activate approach phase. Autothrust decelerates to green dot.
(green dot around 210kt, amber= 230kt on A320)
2. When below amber = select flaps 1. Autothrust decelerates to S speed.
(S speed around 180kt, amber= 200kt on A320).
3. When you are ready for Flaps 2 (typically just before glideslope intercept) select flaps 2. Autothrust decelerates to F speed.
(F speed around 140kt, amber= 185kt on A320)
4. Gear down (exactly when depends on your judgement of a few factors - winds, altitude, speed etc)
5. When you are nearing the point at which you need to be stabilised, select flaps 3. Autothrust keeps maintaining F speed, Amber= moves to 177kt on A320.
6. Very shortly after, select flaps full (if that is landing configuration), Autothrust maintains Vapp (or GSmini if active) and the amber = will disappear as there is no "next flap setting" from flaps full. (you won't see this on the pfd though, as it will be off the upper end of the speed tape)
7. Call for landing checklist.
Amadis - glad you are enjoying the show
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Good morning,
Quite confusing!
1) A/THR will manage F/S/O speeds as speed constraints where we don't have to level-off isn't it? So is there a F/S/O point in our F-PLN? If, not how does it know when to manage these speeds? Does it manage F/S/O in selective mode? Because there can be waypoints between F/O/S with speed restrictions too.
Ok, so you activate approach speed, then only it will display the amber =.
The plane will go down to green dot, around 210kts. But the amber = will come at 230kts.
So you can retract flaps below 230kts. When you are at 1, you will see that S speed is around 180kts but the amber = is at 200kts. The plane will go towards S speed. 180kts is a comfortable to fly with flaps 1 but we can go to 2 below 200kts, so once passed the amber =. When you are at flaps 2, you will see F speed around 140kts. Then, you will see that the amber = is at 185kts. When below 185kts, flaps 3. F speed is a comfortable speed to fly with flaps. Finally, you will see the amber = at 177kt, you can then have flaps full. But you can simply fly with flaps 3 at Fspeed (140kts).
2) Is everything right?
3) Is F speed a comfortable speed for flaps 2 or flaps 3??
4) Do you only see the next amber = when you extend of 1?
Thanks
Quite confusing!
1) A/THR will manage F/S/O speeds as speed constraints where we don't have to level-off isn't it? So is there a F/S/O point in our F-PLN? If, not how does it know when to manage these speeds? Does it manage F/S/O in selective mode? Because there can be waypoints between F/O/S with speed restrictions too.
Ok, so you activate approach speed, then only it will display the amber =.
The plane will go down to green dot, around 210kts. But the amber = will come at 230kts.
So you can retract flaps below 230kts. When you are at 1, you will see that S speed is around 180kts but the amber = is at 200kts. The plane will go towards S speed. 180kts is a comfortable to fly with flaps 1 but we can go to 2 below 200kts, so once passed the amber =. When you are at flaps 2, you will see F speed around 140kts. Then, you will see that the amber = is at 185kts. When below 185kts, flaps 3. F speed is a comfortable speed to fly with flaps. Finally, you will see the amber = at 177kt, you can then have flaps full. But you can simply fly with flaps 3 at Fspeed (140kts).
2) Is everything right?
3) Is F speed a comfortable speed for flaps 2 or flaps 3??
4) Do you only see the next amber = when you extend of 1?
Thanks
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The amber= at 230kt is displayed all the time when
1. flaps 0
2. below 20,000 ft (Max flap operating altitude)
The F/S/O speeds are not managed as constraints, and are not in the flight plan. It really is very simple...
Activate the approach phase on the fmgc (Perf page), and the managed speed becomes green dot. Then extend flaps 1, and managed speed is S speed. Flaps 2/3 and managed speed is F speed. You can do this at any stage of the flight and it will work the same. Obviously in normal operations you will only do it on approach.
I think you need to check your definition of retract. Retract means to pull in. Extend means to push out. So you extend flaps from 0 to 1. You retract flaps from 1 to 0.
3. F speed is comfortable for both flaps 2 and 3. there is very little difference between these settings...
4. You will always see the amber =. It is always Vfe of the next greater flap setting. The only times you dont see any amber= is
1) above 20,000
2) when flaps are full.
1. flaps 0
2. below 20,000 ft (Max flap operating altitude)
The F/S/O speeds are not managed as constraints, and are not in the flight plan. It really is very simple...
Activate the approach phase on the fmgc (Perf page), and the managed speed becomes green dot. Then extend flaps 1, and managed speed is S speed. Flaps 2/3 and managed speed is F speed. You can do this at any stage of the flight and it will work the same. Obviously in normal operations you will only do it on approach.
I think you need to check your definition of retract. Retract means to pull in. Extend means to push out. So you extend flaps from 0 to 1. You retract flaps from 1 to 0.
3. F speed is comfortable for both flaps 2 and 3. there is very little difference between these settings...
4. You will always see the amber =. It is always Vfe of the next greater flap setting. The only times you dont see any amber= is
1) above 20,000
2) when flaps are full.
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Thanks
1) So the amber = will keep coming, one after one, even if you don't EXTEND your flaps?
2) Yes, I wanted to say Extract. So is everything else right?
3) Ok here are my wpt:
- AGOPA : 5000ft - 250kts.
- BANOX: 4500ft - 245kts
---> Green dot speed 230kts.
- LORNI: 3000ft 205kts.
Now, you are in ALT managed. What will you read on the FMA after Banox? Will it arm ALT in Blue? Same question with an OP DES and V/S -1500ft/min.
Thanks
1) So the amber = will keep coming, one after one, even if you don't EXTEND your flaps?
2) Yes, I wanted to say Extract. So is everything else right?
3) Ok here are my wpt:
- AGOPA : 5000ft - 250kts.
- BANOX: 4500ft - 245kts
---> Green dot speed 230kts.
- LORNI: 3000ft 205kts.
Now, you are in ALT managed. What will you read on the FMA after Banox? Will it arm ALT in Blue? Same question with an OP DES and V/S -1500ft/min.
Thanks
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Job.
Dupre, a complex and interesting topic and I am gaining much insight on "the bus" from your and others attempts to answer these questions from France...I am sure your efforts will be rewarded fully some time down route but you truly Sir, have the patience of Job.
Flight sim for PC or MAC, On line access, freedom of information and a limited knowledge on a subject, to which one might feel at 14 they need answers, is a dangerous combination. Only a rich parent or lottery win away from P2F...?
And as for the monkeys and pigskin analogy...been thinking the same but unable to put it quite so eloquently....
Flight sim for PC or MAC, On line access, freedom of information and a limited knowledge on a subject, to which one might feel at 14 they need answers, is a dangerous combination. Only a rich parent or lottery win away from P2F...?
And as for the monkeys and pigskin analogy...been thinking the same but unable to put it quite so eloquently....
Last edited by Axel-Flo; 4th Jan 2015 at 12:47. Reason: Spelling mistake
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1. No, the amber = only changes if you change your flaps.
Conf0, amber= is at 230kt.
Conf1, amber= is at 200kt.
Conf2, amber= is at 185kt.
Conf3, amber= is at 177kt.
ConfF, amber= disappears.
These are true whether you are extending flaps, retracting flaps, or flying without touching flaps.
2. Yes.
3. Need a bit more information. What altitude have you set on FCU? Are you in ALT mode or DES mode? And what altitude are you at?
Conf0, amber= is at 230kt.
Conf1, amber= is at 200kt.
Conf2, amber= is at 185kt.
Conf3, amber= is at 177kt.
ConfF, amber= disappears.
These are true whether you are extending flaps, retracting flaps, or flying without touching flaps.
2. Yes.
3. Need a bit more information. What altitude have you set on FCU? Are you in ALT mode or DES mode? And what altitude are you at?
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Thank you, Alex-Flo, for your kind words, and I agree that Dupre does, in fact, have the patience of Job. On a related note, I have some doubts our young friend is either 14 or from France, but, I suppose, that's neither here nor there.
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The whole thing is challenging me to think about some things in more depth than I would otherwise, and am learning some good stuff.
Anyway if the internet had been around when I was 14, I would probably have been asking thousands of questions myself. Probably a lot less informed than AF330s too.
Anyway if the internet had been around when I was 14, I would probably have been asking thousands of questions myself. Probably a lot less informed than AF330s too.
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It's just that I can't help, but think that someone from France would have a much easier time getting his questions answered on a French forum, especially when those questions concern a French-made aircraft. I don't see a single good reason why he'd come on an English-speaking forum (and then not the correct section) and persist in torturing himself and others.
I doubt this is a potential P2F case either, those guys have very little curiosity in the in-depth workings of their aircraft, especially THIS in-depth.
I doubt this is a potential P2F case either, those guys have very little curiosity in the in-depth workings of their aircraft, especially THIS in-depth.
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True....
Very benevolent and generous in time and patience of Dupre though. I have wondered why if it's a real AB operator why the constant misunderstanding of configuring tied into the Alpha Floor/Alpha Max issues, the understanding of climb thrust being constant and the pitch inputs of AP to maintain climb speed seem to have illuded our OP some how. Power Attitude Trim....manual or even in automation you can't try and maintain speed or attitude by continually changing both pitch and power....it would be mutually incompatible to have computers fighting each other to maintain control of the same criteria?
I also wonder about the desire to drag it round to what looks like some kind of made up flight plan MCDU home built route where speed and Alt constraints are being built in to perhaps let the Home Flight Sim follow a profile before a STAR begins??
Despite all this however it has still been and is being very informative to me on the logic behind this FBW topic......
I also wonder about the desire to drag it round to what looks like some kind of made up flight plan MCDU home built route where speed and Alt constraints are being built in to perhaps let the Home Flight Sim follow a profile before a STAR begins??
Despite all this however it has still been and is being very informative to me on the logic behind this FBW topic......