A320 A/P disconnect
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One little gotcha with keeping the AP on all the way to 20kts or whatever on the 320 is that 45-50 seconds after touchdown, the FMGC goes into the Done phase, so the localizer freq drops out. You would need to manually tune the loc to prevent that from happening.
Just something to keep in mind for those who are hellbent on keeping the automation on a tad longer than most...
Just something to keep in mind for those who are hellbent on keeping the automation on a tad longer than most...
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Training, Practice or Real Life?
If it is a simulator practice, know what is expected in the SOP and fly it. If in Real Life, why the 
did you not divert about 30 minutes ago? In the rare case where a diversion is/was not possible - very rare and you ought to know that, follow the SOP or get a low as possible, shut ALL of it off and land the monster with whatever grace remains possible. That may be a challenge with airplanes that are a bit too smart for their own good (think French FBW types), but one more reason to ask questions within your own shop. Colleagues? Trainers? FOM writers? Chief Pilots if necessary. What it really means is know As Much As Possible about how that semi-stupid FBW system works and learn how to tell the SOB who is driving. Just by asking the question, you are far ahead of many/most others. This forum many not be the best place to find good answers, but please don't quit until you are satisfied. If you drive one of those (FBW) things, you really do need to know how it thinks, ahead of time. If not already obvious, if forced to land in that situation, you'll know it well before hitting the markers. Thoroughly brief your partner and know what each is expected to do, when, long before said markers. Those miserable approaches and landings CAN be made safely, but they require TWO sharp pilots who can out-think the damn FBW and have an absolutely firm plan, regardless of who is PF and PM. That is darn sure not the time to be asking the infamous question, '...what is it doing, now...?' Stick and rudder is not enough. Know your airplane, inside and out and keep your brain several steps ahead of the airplane's brain. Few do; all should.
did you not divert about 30 minutes ago? In the rare case where a diversion is/was not possible - very rare and you ought to know that, follow the SOP or get a low as possible, shut ALL of it off and land the monster with whatever grace remains possible. That may be a challenge with airplanes that are a bit too smart for their own good (think French FBW types), but one more reason to ask questions within your own shop. Colleagues? Trainers? FOM writers? Chief Pilots if necessary. What it really means is know As Much As Possible about how that semi-stupid FBW system works and learn how to tell the SOB who is driving. Just by asking the question, you are far ahead of many/most others. This forum many not be the best place to find good answers, but please don't quit until you are satisfied. If you drive one of those (FBW) things, you really do need to know how it thinks, ahead of time. If not already obvious, if forced to land in that situation, you'll know it well before hitting the markers. Thoroughly brief your partner and know what each is expected to do, when, long before said markers. Those miserable approaches and landings CAN be made safely, but they require TWO sharp pilots who can out-think the damn FBW and have an absolutely firm plan, regardless of who is PF and PM. That is darn sure not the time to be asking the infamous question, '...what is it doing, now...?' Stick and rudder is not enough. Know your airplane, inside and out and keep your brain several steps ahead of the airplane's brain. Few do; all should.
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I think the question is better written:
"I'm planning to perform a manual landing in equal or better than Cat I conditions with CAT2 or CAT3 displayed on the FMA. What is the lowest I can keep the autopilot engaged?"
I would say the correct answer is 80 ft AGL.
"I'm planning to perform a manual landing in equal or better than Cat I conditions with CAT2 or CAT3 displayed on the FMA. What is the lowest I can keep the autopilot engaged?"
I would say the correct answer is 80 ft AGL.
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There is no clear cut answer to this question as there is no limitation .
FMA is showing its highest performance level which is CAT3 DUAL , it does not mean you can go down to cat 3 minima . Are you limited by crew qualification? Airport not authorising simulated cat 3? With AP ON , Passing DH , you are more doing a simulated CAT 3 approach than CAT 1. Or if you plan to disconnect by 80 feet you are then doing a simulated CAT 2 as Autopilot is not mandatory for a CAT 1 , and manual landing is required.
Now let's ask another question , simulated CAT 2/3 are not allowed in a busy airport in cavok weather.
Having CAT 3 DUAL on FMA , what is the lowest height at which you can disconnect AP?
I would say DH CAT 1 . Although your autoflight can do better , you are here limited by local airport requirements.
FMA is showing its highest performance level which is CAT3 DUAL , it does not mean you can go down to cat 3 minima . Are you limited by crew qualification? Airport not authorising simulated cat 3? With AP ON , Passing DH , you are more doing a simulated CAT 3 approach than CAT 1. Or if you plan to disconnect by 80 feet you are then doing a simulated CAT 2 as Autopilot is not mandatory for a CAT 1 , and manual landing is required.
Now let's ask another question , simulated CAT 2/3 are not allowed in a busy airport in cavok weather.
Having CAT 3 DUAL on FMA , what is the lowest height at which you can disconnect AP?
I would say DH CAT 1 . Although your autoflight can do better , you are here limited by local airport requirements.
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Citation2, I don't think you understand the difference between aircraft capability (e.g. indication on FMA), approach type and related minimum altitude for autopilot disconnect.
Airbus FCOM is actually quite clear on this topic (especially compared to some other French "tricks"). If FMA is showing CAT 1 capability, you should disconnect the autopilot at 160ft the latest. If you have CAT 2, CAT 3 SINGLE or CAT 3 DUAL and you plan a manual landing, you should disconnect it at 80ft. Of course, everything assumes an ILS approach - for NPA, limitations are different.
and
There is no reason why you can't use autopilot on a normal Category I ILS approach until 80ft - provided FMA displays capability CAT 2 or better and aircraft remains in desired flight path of course.
Airbus FCOM is actually quite clear on this topic (especially compared to some other French "tricks"). If FMA is showing CAT 1 capability, you should disconnect the autopilot at 160ft the latest. If you have CAT 2, CAT 3 SINGLE or CAT 3 DUAL and you plan a manual landing, you should disconnect it at 80ft. Of course, everything assumes an ILS approach - for NPA, limitations are different.
Minimum height for use of the autopilot in:
- ILS approach when CAT2 or CAT3 is not displayed on the FMA ...160 ft AGL
- ILS approach when CAT2 or CAT3 is not displayed on the FMA ...160 ft AGL
If the flight crew performs an automatic approach without autoland, the autopilot must be disengaged
no later than at 80 ft AGL.
no later than at 80 ft AGL.
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Flyingstone you are confused with autoflight limitation and what the pilot yourself is actually doing .
If you are disconnecting the autopilot at 80 ft you are doing a simulated CAT 2 approach with manual landing.
Well quoted "If the flight crew performs an automatic approach without autoland, the autopilot must be disengaged no later than at 80 ft AGL.". This appears under ILS CATEGORY CAT 2 on FCOM limitations.
If you are disconnecting the autopilot at 80 ft you are doing a simulated CAT 2 approach with manual landing.
Well quoted "If the flight crew performs an automatic approach without autoland, the autopilot must be disengaged no later than at 80 ft AGL.". This appears under ILS CATEGORY CAT 2 on FCOM limitations.
You can never disconnect the autopilot in the Airbus unless you pull circuit breakers to disable computers and put the aircraft into direct law. You can put the aircraft into control stick steering. This will work at any altitude. Minimum altitude to switch to CSS will be governed by your airlines SOP. My airline uses 50 feet below minimums or normally 150 feet on a CAT 1 approach. Disconnect can be down to flare if the approach is not satisfactory. I solve the issue by always flying cat 1 approaches in CSS to maintain currency in the Airbus version of hand flying. Why anyone would couple a cat 1 eludes me. The airplane can fly it just fine. Pilots need practice for the day things go wrong and you must fly the aircraft.
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Sailvi767 - you seem very confused. The autopilot on the A320 is conventional and is disconnected by a button on the sidestick. There is no such system as CSS on Airbus.
Citation 2 - please read the original question in the first post. FlyingStone is bang on the money.
Citation 2 - please read the original question in the first post. FlyingStone is bang on the money.
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Quote from JEPPESEN - GENERAL - RADIO AIDS - ILS
"Unless otherwise coordinated through Flight Standards, ILS signals to Category I runways are not flight inspected below the point that is 100 feet less than the decision altitude (DA). Guidance signal anomalies may be encountered below this altitude."
Whilst I do agree with the discussion pertaining on AFCS limitations vs approach category, are you still legal in that scenario if, as an example, your CAT I DA is 300 ft AGL ?
"Unless otherwise coordinated through Flight Standards, ILS signals to Category I runways are not flight inspected below the point that is 100 feet less than the decision altitude (DA). Guidance signal anomalies may be encountered below this altitude."
Whilst I do agree with the discussion pertaining on AFCS limitations vs approach category, are you still legal in that scenario if, as an example, your CAT I DA is 300 ft AGL ?
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MCDUDE : the original question is : On a CAT I ILS approach, what is the lowest height the A/P can be disconnected with CAT 3 DUAL on FMA?
The answer of flyingstone : 80 feet
"FCOM LIMITATION : ILS CATEGORY 2 : If the flight crew performs an automatic approach without autoland, the autopilot must be disengaged no later than at 80 ft AGL"
Now who is confused ?can' t you read your FCOM ? 80 ft is a limitation only applicable to CAT 2 . Why are you inventing a new non existent limitation?
80 ft is not applicable to CAT 1
If you were keeping the Auto pilot down to 80 feet thats exactly what you would be doing if you asked for a simulated CAT 2 approach.
So again if you are keeping the autopilot down to 80 ft , that's called a simulated CAT 2 and not CAT 1 approach.
The answer of flyingstone : 80 feet
"FCOM LIMITATION : ILS CATEGORY 2 : If the flight crew performs an automatic approach without autoland, the autopilot must be disengaged no later than at 80 ft AGL"
Now who is confused ?can' t you read your FCOM ? 80 ft is a limitation only applicable to CAT 2 . Why are you inventing a new non existent limitation?
80 ft is not applicable to CAT 1
If you were keeping the Auto pilot down to 80 feet thats exactly what you would be doing if you asked for a simulated CAT 2 approach.
So again if you are keeping the autopilot down to 80 ft , that's called a simulated CAT 2 and not CAT 1 approach.
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MCDUDE : the original question is : On a CAT I ILS approach, what is the lowest height the A/P can be disconnected with CAT 3 DUAL on FMA?
The answer of flyingstone : 80 feet
"FCOM LIMITATION : ILS CATEGORY 2 : If the flight crew performs an automatic approach without autoland, the autopilot must be disengaged no later than at 80 ft AGL"
Now who is confused ?can' t you read your FCOM ? 80 ft is a limitation only applicable to CAT 2 . Why are you inventing a new non existent limitation?
80 ft is not applicable to CAT 1
If you were keeping the Auto pilot down to 80 feet thats exactly what you would be doing if you asked for a simulated CAT 2 approach.
So again if you are keeping the autopilot down to 80 ft , that's called a simulated CAT 2 and not CAT 1 approach.
The answer of flyingstone : 80 feet
"FCOM LIMITATION : ILS CATEGORY 2 : If the flight crew performs an automatic approach without autoland, the autopilot must be disengaged no later than at 80 ft AGL"
Now who is confused ?can' t you read your FCOM ? 80 ft is a limitation only applicable to CAT 2 . Why are you inventing a new non existent limitation?
80 ft is not applicable to CAT 1
If you were keeping the Auto pilot down to 80 feet thats exactly what you would be doing if you asked for a simulated CAT 2 approach.
So again if you are keeping the autopilot down to 80 ft , that's called a simulated CAT 2 and not CAT 1 approach.
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Quote:
Certainly on our route network (Europe) there is no requirement to tell ATC. It doesn't change anything for them, and therefore they're not interested. We used to do it, and would invariably be met by silence, then a confused 'Roger' and occasionally a 'LVP protections are not in place.' It may be different in other parts of the world of course
I am shocked how stupid pilots with the responsibility for hundreds of lives are.
@seen_the_box: Have you ever read about the SIA B777 ending off the runway in munich? They made an auto land on an CAT I ILS beam without telling ATC. So just as touching down the previous departing aircraft overflew the LOC antenna causing the localizer to bend. The B777 followed it and departed the runway.
Munich by the way is in the middle of europe.
Certainly on our route network (Europe) there is no requirement to tell ATC. It doesn't change anything for them, and therefore they're not interested. We used to do it, and would invariably be met by silence, then a confused 'Roger' and occasionally a 'LVP protections are not in place.' It may be different in other parts of the world of course
I am shocked how stupid pilots with the responsibility for hundreds of lives are.
@seen_the_box: Have you ever read about the SIA B777 ending off the runway in munich? They made an auto land on an CAT I ILS beam without telling ATC. So just as touching down the previous departing aircraft overflew the LOC antenna causing the localizer to bend. The B777 followed it and departed the runway.
Munich by the way is in the middle of europe.
Only half a speed-brake
So again if you are keeping the autopilot down to 80 ft , that's called a simulated CAT 2 and not CAT 1 approach.
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Part of the briefing for a practice autoland will cover the fact that LVOs are not in force, and the beam will not be protected. We are therefore prepared to take over manually and complete the landing, assuming visual references are sufficient (which they should be, considering that by definition the weather for a simulated autoland will always be CATI+). It is part of the TEM when flying such an approach.
I'll say it again: There is no requirement to tell ATC that you are conducting a practice autoland. It doesn't change anything for them: at a busy airfield, they are not suddenly going to give you low vis protections just because you want to practice. The SIA incident you cited could have been avoided if the crew had disconnected the automatics when it became clear that they weren't coping adequately with the situation, or flown a go around/baulked landing. They allowed the autopilot to steer them into the grass. Proper briefing, and proper monitoring is imperative to avoid such an occurrence.
I'll say it again: There is no requirement to tell ATC that you are conducting a practice autoland. It doesn't change anything for them: at a busy airfield, they are not suddenly going to give you low vis protections just because you want to practice. The SIA incident you cited could have been avoided if the crew had disconnected the automatics when it became clear that they weren't coping adequately with the situation, or flown a go around/baulked landing. They allowed the autopilot to steer them into the grass. Proper briefing, and proper monitoring is imperative to avoid such an occurrence.
Last edited by seen_the_box; 27th Nov 2015 at 09:41.
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I believe you, that, according to your company sop, there is no requirement to tell atc. But as the SIA shows you, they were not able the cover the outcome of this.
If you tell ATC in a busy environment that you will practice autoland, they will never protect the respective areas around the runway. Instead they tell you to land manually, because autoland is not save on an unprotected ILS beam. Even if Chuck Yeager, or someone who thinks he is, is on the controls.
If you tell ATC in a busy environment that you will practice autoland, they will never protect the respective areas around the runway. Instead they tell you to land manually, because autoland is not save on an unprotected ILS beam. Even if Chuck Yeager, or someone who thinks he is, is on the controls.
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Instead they tell you to land manually, because autoland is not save on an unprotected ILS beam. Even if Chuck Jeager, or someone who thinks he is, is on the controls.
There is nothing inherently 'unsafe' about an autoland on an unprotected beam: as I already stated, you just have to have a plan in the event that the beam is compromised. If it was unsafe, it certainly wouldn't be permitted in line operations, either by company or manufacturer. The fact that it is permitted should be a pretty clear indication that it is not considered unsafe. You always have the option of taking over manually, or going around.
Only half a speed-brake
Certainly on our route network (Europe) there is no requirement to tell ATC. It doesn't change anything for them, and therefore they're not interested. We used to do it, and would invariably be met by silence, then a confused 'Roger' and occasionally a 'LVP protections are not in place.' It may be different in other parts of the world of course
The 777 incident in Munich was a case of autoland gone wrong in non-LVP (protections not in place) situation, yes. Factual report here from BFU.
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Quote from JEPPESEN - GENERAL - RADIO AIDS - ILS
"Unless otherwise coordinated through Flight Standards, ILS signals to Category I runways are not flight inspected below the point that is 100 feet less than the decision altitude (DA). Guidance signal anomalies may be encountered below this altitude."
Whilst I do agree with the discussion pertaining on AFCS limitations vs approach category, are you still legal in that scenario if, as an example, your CAT I DA is 300 ft AGL ?
"Unless otherwise coordinated through Flight Standards, ILS signals to Category I runways are not flight inspected below the point that is 100 feet less than the decision altitude (DA). Guidance signal anomalies may be encountered below this altitude."
Whilst I do agree with the discussion pertaining on AFCS limitations vs approach category, are you still legal in that scenario if, as an example, your CAT I DA is 300 ft AGL ?