A new flight mode annunciation concept
The value of changing the FMA depends on the viewpoint.
A conventional view of automatic flight is that the aircraft's state is determined by using the basic instruments; if the flight path is not as required then the auto flight system should be adjusted (or disengaged) and the modes and selections cross checked with the crew's intention.
An alternative view reverses this, where the FMA is used to deduce what the automation is doing, or should be doing, with little reference to the basic instruments. Then the aircraft flight path is inferred from the annunciation. This often results in 'what is it doing now' and contributes to reduced awareness of attitude or speed.
Locating mode annunciation closer to the relevant instrument parameter is an interesting idea, but it might not direct attention to the associated instrument parameter as assumed.
If a pilot looks for a mode annunciation, s/he will 'see' that mode without necessarily being aware of the adjacent instrument display; vice versa, look for an instrument reading and not 'see' the annunciation.
Whilst many accident and incident reports cite 'failure to look at the FMA', such conclusions more often hide problems associated with lack of awareness of the aircraft state, poor instrument scan, the 'mantra' need follow SOPs and monitor everything, but with little thought of workload and the importance of understanding.
The proposal is interesting, but is it a solution seeking a problem?
What specific issue is it designed to address?
A conventional view of automatic flight is that the aircraft's state is determined by using the basic instruments; if the flight path is not as required then the auto flight system should be adjusted (or disengaged) and the modes and selections cross checked with the crew's intention.
An alternative view reverses this, where the FMA is used to deduce what the automation is doing, or should be doing, with little reference to the basic instruments. Then the aircraft flight path is inferred from the annunciation. This often results in 'what is it doing now' and contributes to reduced awareness of attitude or speed.
Locating mode annunciation closer to the relevant instrument parameter is an interesting idea, but it might not direct attention to the associated instrument parameter as assumed.
If a pilot looks for a mode annunciation, s/he will 'see' that mode without necessarily being aware of the adjacent instrument display; vice versa, look for an instrument reading and not 'see' the annunciation.
Whilst many accident and incident reports cite 'failure to look at the FMA', such conclusions more often hide problems associated with lack of awareness of the aircraft state, poor instrument scan, the 'mantra' need follow SOPs and monitor everything, but with little thought of workload and the importance of understanding.
The proposal is interesting, but is it a solution seeking a problem?
What specific issue is it designed to address?
a) All the information on the PrimaryFlightDisplay, and others, is important at any time of flight -
You have quoted me replying to #18 where a non pilot was asking about removing information after 12 or more hours of flying.
What information would you remove from a standard Airbus A320/321 PFD/ND/EWD/SD ?
What information would you remove from those displays in an A330 after 12 hours of flight - possibly as you were just starting your approach??
What information would you remove from a standard Airbus A320/321 PFD/ND/EWD/SD ?
What information would you remove from those displays in an A330 after 12 hours of flight - possibly as you were just starting your approach??
Last edited by Uplinker; 17th Nov 2016 at 15:59.
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Ladies and Gents
Many thanks to those of you who completed or will complete the "surveymonkey" questions. You also made some very valid points here in the forum.
The modified display style was tested in an eye-tracking experiment and the main goal was to evaluate, if the number of "missed" mode transitions can be reduced. The analysis is ongoing. I am aware that the involved display is not the latest, but the point here is really the philosophy, not the "graphics". Obviously the proposed design has some drawbacks, such as drawing the attention "away" from a critical parameter under certain conditions. I agree that the best safety feature is a properly trained pilot, but at the same time we should not stop exploring new ideas from the engineering side.
Feel free to share the survey and many thanks again.
avionics_engineer
Many thanks to those of you who completed or will complete the "surveymonkey" questions. You also made some very valid points here in the forum.
The modified display style was tested in an eye-tracking experiment and the main goal was to evaluate, if the number of "missed" mode transitions can be reduced. The analysis is ongoing. I am aware that the involved display is not the latest, but the point here is really the philosophy, not the "graphics". Obviously the proposed design has some drawbacks, such as drawing the attention "away" from a critical parameter under certain conditions. I agree that the best safety feature is a properly trained pilot, but at the same time we should not stop exploring new ideas from the engineering side.
Feel free to share the survey and many thanks again.
avionics_engineer
I'm with the guys who talk about clutter. We need to reduce the information, not add to it. PFDs are getting more complex with information overload. Not only is this distracting, it's fatiguing. Engineers add more and more and add to the problems. If a pilot designed a flight information display from the outset - it would look different.
Possible thread creep, but relevant I hope:
On the Airbus, the only time the speed control part of the FMA is blank is when the autothrust is completely off - i.e., not active or armed. At all other times, it gives the status of the Autothrust; either Speed/Mach or Thrust Climb or Thrust Idle or MAN FLEX, TOGA etc.
I don't know Boeing but on the ? 777 PFD shown in this thread; during FLCH mode, the Autothrust 'speed' annunciation seemed to move over to the pitch box leaving the top left speed control box blank.
So I wonder is there a danger that since 777 pilots get used to seeing a blank box top left when the Autothrust is still operating, this might lead to some missing the clues when the Autothrust is actually off for real?
(For example we have seen from the SFO 777 crash that non movement of normally moving thrust levers is not necessarily a clue that the autothrust is not controlling speed?)
Could this be why the sort of additions proposed by the OP might be thought necessary?
(NB: I have not flown Boeing, but this is not an A vs B bashing at all, I am merely trying to understand the psychology and causes of some accidents).
On the Airbus, the only time the speed control part of the FMA is blank is when the autothrust is completely off - i.e., not active or armed. At all other times, it gives the status of the Autothrust; either Speed/Mach or Thrust Climb or Thrust Idle or MAN FLEX, TOGA etc.
I don't know Boeing but on the ? 777 PFD shown in this thread; during FLCH mode, the Autothrust 'speed' annunciation seemed to move over to the pitch box leaving the top left speed control box blank.
So I wonder is there a danger that since 777 pilots get used to seeing a blank box top left when the Autothrust is still operating, this might lead to some missing the clues when the Autothrust is actually off for real?
(For example we have seen from the SFO 777 crash that non movement of normally moving thrust levers is not necessarily a clue that the autothrust is not controlling speed?)
Could this be why the sort of additions proposed by the OP might be thought necessary?
(NB: I have not flown Boeing, but this is not an A vs B bashing at all, I am merely trying to understand the psychology and causes of some accidents).
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I don't know Boeing but on the ? 777 PFD shown in this thread; during FLCH mode, the Autothrust 'speed' annunciation seemed to move over to the pitch box leaving the top left speed control box blank.
So I wonder is there a danger that since 777 pilots get used to seeing a blank box top left when the Autothrust is still operating, this might lead to some missing the clues when the Autothrust is actually off for real?
So I wonder is there a danger that since 777 pilots get used to seeing a blank box top left when the Autothrust is still operating, this might lead to some missing the clues when the Autothrust is actually off for real?
I'm not really sure why in this video the autothrottle has been disconnected (Blank box) - if you're flying along and hit FLCH, you should get either THR or IDLE then HOLD depending if you're going up or down.
A blank left FMA box indicates exactly that – the autothrottle is NOT operating. If in a vertical mode other than FLCH SPD, however, the autothrottle, if armed, can still "wake up" and provide stall protection; this is what brought Asiana undone.
OK, thanks skkm. So like the Airbus, the Boeing FMA speed box will always display the Autothrust status, and only if it is inactive and unarmed, will the speed box ever be blank?
In that case I return to my personal opinion that this enhancement is not required and adds extra clutter.
Yeah, I realised that, my point was that in the example the speed box was blank while the speed was being controlled, (by the elevators), leading to a potential negative as PEI3721 picked up.
In that case I return to my personal opinion that this enhancement is not required and adds extra clutter.
The SPD annunciation moves over to the vertical FMA box because the speed is now being controlled by pitch rather than the autothrottle.
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If the A/T is disconnected, the FMA will always be blank. However, the A/T can (and usually is) still be armed in this case (by having the arm switches on the MCP on), and as such is able to perform its stall protection "wake up" function depending on vertical mode. There is no indication other than the position of the arm switches of this status.
The only time in normal operations that you'd see the left FMA blank is a manual thrust landing.
I realised that, my point was that in the example the speed box was blank while the speed was being controlled, (by the elevators), leading to a potential negative as PEI3721 picked up.
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There is the opposite issue, though, which is the crux of the Asiana accident: while you have an indication in the left box (HOLD) whilst in a speed-on-elevator vertical FD mode, the autothrottle will not wake up to provide speed protection should you get slow in manual flight.
