A320 FMA ''G/S'' callout
Re #20, the most important aspect of a callout is to report the system condition enabling both pilots to have a common understanding of the situation. That can be very difficult depending on the context of the situation and what is actually happening.
The ‘golden’ mantra for the need to understand the FMA requires additional clarification with respect to what the aircraft auto-systems are doing, have been programmed to do, or the crew’s intention and the expected changes; it’s far more important to understand what the aircraft is actually doing than what the FMA indicates.
A problem in calling all ‘normal states’ is that this can lead to ‘wish think’ - you think that you have said the words, but may not have; or ‘hear think’ - you believe that an expected conditions exists, but in fact does not.
The better approach is to only call the undesirable states - ‘no glideslope’, at a time when it should be armed / engage. This has the advantage of reducing ‘callout clutter’ (soggy SOPs), such as GS armed, GS engaged, GS star/dual, etc.
Unfortunately this ‘deviation’ only method requires that both crew have a common understanding of what is intended; standard procedures could help, as might a good briefing, or improved cross crew communication; so FMA callouts are used for this but may not be the best method.
And then again with positive calls there is potential confusion by intermixing normal and abnormal states using the same words. e.g. GS mode armed / engaged vs GS deviation in auto flight or the GS component of an unstable approach.
Your choice, but choose carefully.
The ‘golden’ mantra for the need to understand the FMA requires additional clarification with respect to what the aircraft auto-systems are doing, have been programmed to do, or the crew’s intention and the expected changes; it’s far more important to understand what the aircraft is actually doing than what the FMA indicates.
A problem in calling all ‘normal states’ is that this can lead to ‘wish think’ - you think that you have said the words, but may not have; or ‘hear think’ - you believe that an expected conditions exists, but in fact does not.
The better approach is to only call the undesirable states - ‘no glideslope’, at a time when it should be armed / engage. This has the advantage of reducing ‘callout clutter’ (soggy SOPs), such as GS armed, GS engaged, GS star/dual, etc.
Unfortunately this ‘deviation’ only method requires that both crew have a common understanding of what is intended; standard procedures could help, as might a good briefing, or improved cross crew communication; so FMA callouts are used for this but may not be the best method.
And then again with positive calls there is potential confusion by intermixing normal and abnormal states using the same words. e.g. GS mode armed / engaged vs GS deviation in auto flight or the GS component of an unstable approach.
Your choice, but choose carefully.
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Lexis,
How does your captain read out AP1, AP1+2 and OP CLB?
If he's going to get silly, you should match him. Read out the FMA letter by letter on takeoff. That should get him to see how silly he's being.
How does your captain read out AP1, AP1+2 and OP CLB?
If he's going to get silly, you should match him. Read out the FMA letter by letter on takeoff. That should get him to see how silly he's being.
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A problem in calling all ‘normal states’ is that this can lead to ‘wish think’ - you think that you have said the words, but may not have; or ‘hear think’ - you believe that an expected conditions exists, but in fact does not.
The better approach is to only call the undesirable states - ‘no glideslope’, at a time when it should be armed / engage. This has the advantage of reducing ‘callout clutter’ (soggy SOPs), such as GS armed, GS engaged, GS star/dual, etc.
The better approach is to only call the undesirable states - ‘no glideslope’, at a time when it should be armed / engage. This has the advantage of reducing ‘callout clutter’ (soggy SOPs), such as GS armed, GS engaged, GS star/dual, etc.
Same goes for the guys calling '' Clear right side'' every 10 seconds during taxi while barely looking out. Like dude, I'm not blind. Why don't you keep looking outside and call my attention only when there is a threat? Keep your energy for God Sake.
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A problem in calling all ‘normal states’ is that this can lead to ‘wish think’
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I dunno. Please share the reason. If I had to guess: I would think to avoid unnecessary thrust variation. Turbine engines don't like thrust variation. And also it's safer I suppose.Going from ''DES'' to ''OP DES'' would possibly means going from -500/-1000 feet a minute to a much higher rate of descent as the engines would go to idle.
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Hi pineteam
Let some more guesses come in. The point I am making is the amount of thought that goes in designing an aeroplane. So it shouldn't be brushed aside merely on personal opinion.
Let some more guesses come in. The point I am making is the amount of thought that goes in designing an aeroplane. So it shouldn't be brushed aside merely on personal opinion.
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OK, I’ll play.
In CLB thrust is fixed. Therefore changing from NAV to HDG will have no effect on Aircraft trajectory. The engineers know the thrust setting in CLB is always CLB
Conversely, In DES thrust is variable from IDLE to SPD/MACH. My guess is the engineers are trying to minimize the variable state of thrust in DES by using a mode reversion to force thrust into the SPD mode.
This is the same reason when changing at the FCU altitude during ALT*. Thrust is variable during ALT*, therefore a mode reversion to SPD is forced to set a fixed thrust setting.
Only half a speed-brake
a) The basic rule is that the A/C must never do anything that is un-commanded. Pitch-up and pitch-down included.
b) The reversion is a reaction to what is effectively a failure of the DES mode (unable to compute), and that - just like on any other aircraft - must be fail-passive. I.e. ok-to-fail-but-need-to-stay.
In the very likely case when the DES is following a V-NAV geometric segment (60% of the time, my guess), or not flying exactly at the target speed (almost all of the other time), the reversion from DES to OPDES would either
- (1) set IDLE THR and dive the aircraft for the speed
- (2-i) increase pitch and the descent rate to accelerate towards the IAS target
- (2-ii) reduce pitch and the descent rate to slow down towards the IAS target.
Either of those would be a violation of the basic FBW design principles ("a" above) or certification predicaments ("b" above).
Or in simple layman's view: DES is V-NAV path (geometrical trajectory) mode. Once you invalidate that by pulling HDG, V/S is the next closest thing. OP DES is most definitely not.
[Dislclaimer: I enjoyed HDG+V-NAV on the 737.]
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I think that vilas had actually something else as his main point, this was just a side-quest.
It is that designers of the aircraft and of the procedures work in tight coordination to give us a carefully assembled product that is safe, proofed against human error as much as possible. And go seriously wide and deep to achieve that, embracing all the experience the fleet has accumulated in 25 years worldwide. Those who disregard manufacturer's advice given through OEM's FCOM SOPs are brave, bold and playing with fire. It can be done, but to do it right the resources needed are enormous and result never better than the original. More likeable? Sure, but not better.
Think of this one: The aircraft is born and released to the world with the following legal and binding documents
- Noise Certificate
- W&B Manual
- AFM
- ECAM
- QRH
- MMEL
Not the FCOM. FCOM is just a suggestion for operating it inside the limits set in the above certification package. If you re-create the FCOM, do you also re-create the MEL OPS-PROC section? If not, do the MMEL procedures still fit against the SOP's that you have? Similar for OEB's. Just an example.
It is human to think to know better, applies to chief-pilots and CAAs (!) as well. Some steer away from the desire, some fall for it, only few make it through. Hat's off to them, though the whole endeavour is of a questionable motivation.
my 3pc
b) The reversion is a reaction to what is effectively a failure of the DES mode (unable to compute), and that - just like on any other aircraft - must be fail-passive. I.e. ok-to-fail-but-need-to-stay.
In the very likely case when the DES is following a V-NAV geometric segment (60% of the time, my guess), or not flying exactly at the target speed (almost all of the other time), the reversion from DES to OPDES would either
- (1) set IDLE THR and dive the aircraft for the speed
- (2-i) increase pitch and the descent rate to accelerate towards the IAS target
- (2-ii) reduce pitch and the descent rate to slow down towards the IAS target.
Either of those would be a violation of the basic FBW design principles ("a" above) or certification predicaments ("b" above).
Or in simple layman's view: DES is V-NAV path (geometrical trajectory) mode. Once you invalidate that by pulling HDG, V/S is the next closest thing. OP DES is most definitely not.
[Dislclaimer: I enjoyed HDG+V-NAV on the 737.]
---------------------
I think that vilas had actually something else as his main point, this was just a side-quest.
It is that designers of the aircraft and of the procedures work in tight coordination to give us a carefully assembled product that is safe, proofed against human error as much as possible. And go seriously wide and deep to achieve that, embracing all the experience the fleet has accumulated in 25 years worldwide. Those who disregard manufacturer's advice given through OEM's FCOM SOPs are brave, bold and playing with fire. It can be done, but to do it right the resources needed are enormous and result never better than the original. More likeable? Sure, but not better.
Think of this one: The aircraft is born and released to the world with the following legal and binding documents
- Noise Certificate
- W&B Manual
- AFM
- ECAM
- QRH
- MMEL
Not the FCOM. FCOM is just a suggestion for operating it inside the limits set in the above certification package. If you re-create the FCOM, do you also re-create the MEL OPS-PROC section? If not, do the MMEL procedures still fit against the SOP's that you have? Similar for OEB's. Just an example.
It is human to think to know better, applies to chief-pilots and CAAs (!) as well. Some steer away from the desire, some fall for it, only few make it through. Hat's off to them, though the whole endeavour is of a questionable motivation.
my 3pc
Last edited by FlightDetent; 7th Sep 2018 at 12:22.
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FD
All of what you wrote is correct including the answer to my question. I had received a reply similar to that from the Airbus. The point I was making as always is without consulting the manufacturer don't change or manufacture procedure. It's not that simple. I am never tired of quoting the incident involving JetStar Australia and two other airlines of badly busting minima in poor visibility because they changed the priority of reading FMA during go around. It could have ended in tragedy. It is very simple to fly the Airbus but not that simple to understand it deeply. To keep it that way just fly the way it is recommended. Otherwise dig through the manuals write down every thing you don't like or understand and ask the manufacturer. It is very time consuming.
All of what you wrote is correct including the answer to my question. I had received a reply similar to that from the Airbus. The point I was making as always is without consulting the manufacturer don't change or manufacture procedure. It's not that simple. I am never tired of quoting the incident involving JetStar Australia and two other airlines of badly busting minima in poor visibility because they changed the priority of reading FMA during go around. It could have ended in tragedy. It is very simple to fly the Airbus but not that simple to understand it deeply. To keep it that way just fly the way it is recommended. Otherwise dig through the manuals write down every thing you don't like or understand and ask the manufacturer. It is very time consuming.
Originally Posted by Flight Detent
[Disclaimer: I enjoyed HDG+V-NAV on the 737.]
Originally Posted by Flight Detent
Not the FCOM. FCOM is just a suggestion for operating it inside the limits set in the above certification package.
I can think of a few dumb designed-in features/procedures...
Only half a speed-brake
The certification package is AFM, MMEL, CDL, W&B, like 4 puzzle pieces. The FCOM / OEM's SOP set serves as a frame to them, so I can handle the big picture without studying the individual pieces and how they snap together. The debate above was about some inevitable consequences of modifying the factory guidance.
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Why do some pilots ALWAYS call CAT 3 Single when they diconnect the Auto Pilot?
No aircraft can be do any sort of Auto Land with no Auto Pilot. Why not wait till the aircraft downgrades to Cat 1?
We don't select Flap or Gear and then call Intermediate setting while waiting for the system to achieve the desired setting.
No aircraft can be do any sort of Auto Land with no Auto Pilot. Why not wait till the aircraft downgrades to Cat 1?
We don't select Flap or Gear and then call Intermediate setting while waiting for the system to achieve the desired setting.
Also, unless Your SOP is different but in our SOP, if you have already Runway in sight and called « Runway continue » with AP off, it’s not required not useful to call out « land » on FMA or « Checked » after the auto call out « 100 above » and « runway continue » at minimum. But still lots of people are doing it.
Last edited by pineteam; 24th Sep 2018 at 05:06. Reason: made a correction.
I have always said “lock star” for LOC* and “glide star” for G/S*
I don’t remember if these were my own invention or what we were told to say, but the phrases seem to work fine and have never been confused for anything else.
I don’t remember if these were my own invention or what we were told to say, but the phrases seem to work fine and have never been confused for anything else.
