Flybe AP has a 'Plummet' Mode?
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I didn't mean to be automatically assuming automation dependency (even though being "experienced" is not an automatic exclusion from the category -- the famous "Children of the Magenta" video is 19 years old now) -- I'm just coming up with various scenarios that could explain the situation. In short, you can boil my last post down to: If the FD was showing a descent while they were climbing due to misset modes, why didn't they turn it off? And tried to answer that question with a plausible scenario from my experience.
Just about this one point, if it's caught on the ground then I agree. But if caught right after takeoff, then any way I see it the right move is to turn it off, and untangle the mess later at a few thousand feet. Not during the initial sequence of gear, flaps, thrust, speed, freq change, etc.
Just about this one point, if it's caught on the ground then I agree. But if caught right after takeoff, then any way I see it the right move is to turn it off, and untangle the mess later at a few thousand feet. Not during the initial sequence of gear, flaps, thrust, speed, freq change, etc.
Last edited by Vessbot; 11th Nov 2018 at 06:05.
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No, it is not possible to have FD mode but not seeing the FD in the dash 8, so yes they had a command bar showing a descent.
the initial pitch for take off is 15degree, at acceleration flaps are selected to zero, the nose is lowered to the FD GA bar (around 8 degree), then the autopilot is asked for engagement, what will engage the pitch mode, if the nose is not lowered to the GA bar, when engaging the autopilot the FD will synchronise to the current pitch and as said before go to pitch mode.
As it should done, if my FO call AP engagment too soon and not sync with the GA FD bar, I will ask them to go to the GA bar before engagement of AP, then explain why it is important.
You can try as much to understand what happened in their brain, you won t ... read the AAIB report (link at the beginning of the forum). In the world of Dash 8, I m sure it is not the first time pilot take off with wrong setting of FD, it is just probably the first time it went that far before reaction ... But they did appropriate reaction with the ground proximity warning and continued the flight safely.
we can all do mistake, we are all Human ... But we can all learn from mistake of other instead of saying : it won't happen to me, impossible, I can't do this kind of mistake ...
the initial pitch for take off is 15degree, at acceleration flaps are selected to zero, the nose is lowered to the FD GA bar (around 8 degree), then the autopilot is asked for engagement, what will engage the pitch mode, if the nose is not lowered to the GA bar, when engaging the autopilot the FD will synchronise to the current pitch and as said before go to pitch mode.
As it should done, if my FO call AP engagment too soon and not sync with the GA FD bar, I will ask them to go to the GA bar before engagement of AP, then explain why it is important.
You can try as much to understand what happened in their brain, you won t ... read the AAIB report (link at the beginning of the forum). In the world of Dash 8, I m sure it is not the first time pilot take off with wrong setting of FD, it is just probably the first time it went that far before reaction ... But they did appropriate reaction with the ground proximity warning and continued the flight safely.
we can all do mistake, we are all Human ... But we can all learn from mistake of other instead of saying : it won't happen to me, impossible, I can't do this kind of mistake ...
For those who don’t know: Pilots setting up a commercial airliner commonly program in the departure that is expected before obtaining the departure clearance. This is because there is plenty to do during the turnaround, and the clearance is often not available until 15 mins before scheduled off blocks time. We don’t normally wait and program in the departure at this late point, because there is too much to do with coordinating with ATC, ground crews, cabin crew, checklists etc to get away on time. What we do is put in what we expect from the filed flight plan coupled with experience and knowledge of the particular airfield. However, if the departure we read states the cleared altitude or level will be X, many operators/pilots will set X-100’ to remind themselves that the departure clearance and/or cleared level has not been confirmed by ATC.
Departure block altitudes or levels tend to be a whole number, so something like 6900 or 2900 instead of 7000 or 3000 respectively will stand out as being wrong and need checking. During departure if the cleared level was completely missed and not reset, at least the aircraft would climb away towards an expected level for that normal published departure.
This operator obviously sets 0000 altitude before clearance had been obtained, but in the light of this incident, and the way the Q400 flight director works; perhaps Q400 SOP should now be changed so that zero altitude is never set, and their before take-off checks re-written to include a positive check of the cleared level that has been set before lining up.
The incident is very worrying in that the FD pitch down command was either not noticed or not queried before AP engagement, and then once engaged, neither pilot appears to have noticed the abrupt pitch down of the aircraft until the GPWS alerted them. I would recommend some FD and AP misbehaviour scenarios soon after take-off during the next year or so of SIM tests to improve pilots’ scan and monitoring at such critical times.
Departure block altitudes or levels tend to be a whole number, so something like 6900 or 2900 instead of 7000 or 3000 respectively will stand out as being wrong and need checking. During departure if the cleared level was completely missed and not reset, at least the aircraft would climb away towards an expected level for that normal published departure.
This operator obviously sets 0000 altitude before clearance had been obtained, but in the light of this incident, and the way the Q400 flight director works; perhaps Q400 SOP should now be changed so that zero altitude is never set, and their before take-off checks re-written to include a positive check of the cleared level that has been set before lining up.
The incident is very worrying in that the FD pitch down command was either not noticed or not queried before AP engagement, and then once engaged, neither pilot appears to have noticed the abrupt pitch down of the aircraft until the GPWS alerted them. I would recommend some FD and AP misbehaviour scenarios soon after take-off during the next year or so of SIM tests to improve pilots’ scan and monitoring at such critical times.
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Some of us need to look at a google image for a second. Unlike many other types, there IS NO Flight ALt "Window" displaying the "000" or Alt at all. It's just a knob on the panel and all the actual figures are on screen in a Q400.
Alt Sel was always a Pain..... when I moved onto it the heading bugs weren't even synced on both sides. Still, a very capable and powerful beast.
3,500hrs on type before anyone wonders. Can't fathom how this happened though if the crew were paying attention. The Q400 requires concentration at all times. You simply cannot leave it alone. and you do need your feet on the pedals as well.
Happily a long way from the things now.
Alt Sel was always a Pain..... when I moved onto it the heading bugs weren't even synced on both sides. Still, a very capable and powerful beast.
3,500hrs on type before anyone wonders. Can't fathom how this happened though if the crew were paying attention. The Q400 requires concentration at all times. You simply cannot leave it alone. and you do need your feet on the pedals as well.
Happily a long way from the things now.
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No, it is not possible to have FD mode but not seeing the FD in the dash 8, so yes they had a command bar showing a descent.
the initial pitch for take off is 15degree, at acceleration flaps are selected to zero, the nose is lowered to the FD GA bar (around 8 degree), then the autopilot is asked for engagement, what will engage the pitch mode, if the nose is not lowered to the GA bar, when engaging the autopilot the FD will synchronise to the current pitch and as said before go to pitch mode.
the initial pitch for take off is 15degree, at acceleration flaps are selected to zero, the nose is lowered to the FD GA bar (around 8 degree), then the autopilot is asked for engagement, what will engage the pitch mode, if the nose is not lowered to the GA bar, when engaging the autopilot the FD will synchronise to the current pitch and as said before go to pitch mode.
If you're used to following the FD (normal for my plane) it's inconceivable to not notice that it's down in the dirt.
But if you're used to ignoring it, it's a much smaller gap to bridge from "it's somewhere down there in the blue" to "it's somewhere down there in the brown." Not noticing is now a lot more plausible, and according to your normal-case scenario, it's easy to see how they could engage the AP at the routine time.
Of course all this only explains the pre-AP engagement phase.
Last edited by Vessbot; 11th Nov 2018 at 20:55.
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You can try as much to understand what happened in their brain, you won t ... read the AAIB report (link at the beginning of the forum). In the world of Dash 8, I m sure it is not the first time pilot take off with wrong setting of FD, it is just probably the first time it went that far before reaction ... But they did appropriate reaction with the ground proximity warning and continued the flight safely.
we can all do mistake, we are all Human ... But we can all learn from mistake of other instead of saying : it won't happen to me, impossible, I can't do this kind of mistake ...
I read the AAIB bulletin which I had skipped over before, so thanks for pointing me to it. It explicitly answered one of my questions: "During the next 15 seconds, whilst the crew were completing the ‘after takeoff’ checklist, the aircraft descended at an increasing rate with the pitch attitude reducing from about 10° nose-up, to 8° nose-down."
This aspect of the scenario is well-addressed at my airline, where the after takeoff checklist is done entirely by the PM, silently; and I'm glad for that.
Another interesting find from the bulletin is that it lists 3 similar incidents from the same operator. In 2 of them, they saw the pitch down after AP engagement right away, and stopped it after about 150 feet. In the third, they saw the misset modes and fixed them before AP engagement.
As far as being unable to understand what happened in their brain, I'm not sure whether you mean in general, or about this incident. But eiter way I disagree. Sometimes you're left with no answer, sometimes you end up with a fairly good guess, and sometimes it's obvious. But at any rate, from our perspective as pilots it's very important to try to learn that lesson so we don't repeat it ourselves, as it is a cause of the accident chain. It's just as important as the guys who piece together the aircraft to find out what broke before impact, or read the FDR to see the sequence of mechanical events, etc.
As far as the brain-sequence of this particular incident, it's becoming clearer and clearer to me, thanks to:
- the description in the AAIB bulletin
- info from you guys who have flown the type
- similar experiences of my own
Something not yet mentioned in the thread is that they were rushed to takeoff with a late second engine start, a quick flurry of accomplishing the remaining procedures, one of which was interrupted by the takeoff clearance. Introspection moment #1: This happens to us all the time. Even though when I shake hands with the Captain after sitting down for leg #1 and he goes through the usual introductory spiel which most of the time includes something like "we won't ever let ourselves get rushed, that's when you miss stuff and mistakes happen. If we ever need more time, we own the parking brake and we'll make more time;" Yet it happens anyway.
So they do the last-second flurry of checklists, during which, by the way, they do catch that the modes are wrong! But unfortunately fix only part of the problem, leaving the modes still misset. Introspection moment #2: When rushed and you fix a problem, it's extremely easy to feel that mental reward of fixing it: "Aha! all good now" and don't necessarily take the step back and make sure the big picture is OK, which may include a still-unfixed second or third part of the problem. By getting that "aha!" you feel satisfied to continue on.
So they do that, continue with the takeoff, fail to notice that the pitch bar is "down there in the brown" as I noted in my previous post, and engage the AP at the routine time. Now that the AP is on, we can all rest easy right?
And this should be an introspection moment for all you guys where the SOP has both pilots involved in the after takeoff checklist.For me introspection moment #3 comes where my type has a much simpler vertical mode scheme and it is literally impossible to make this particular mistake. If I ever move to a type like the one in this incident, can I bring some of my habits with me? Even if I fastidiously follow the new SOP, can my old habits rear up in a moment of hurry and/or high workload?
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Thanks for the exposition, and it goes a long way toward explaining to me what happened. To make sure I understand you right, I'll repeat it in my own words: On a normal TO, the FD is only capable of showing 8 degrees, where you normally pitch to ~15. (So far so good?) So on a routine take off, (before acceleration) you're used to ignoring the pitch bar as you're flying ~7 degrees above it.
If you're used to following the FD (normal for my plane) it's inconceivable to not notice that it's down in the dirt.
But if you're used to ignoring it, it's a much smaller gap to bridge from "it's somewhere down there in the blue" to "it's somewhere down there in the brown." Not noticing is now a lot more plausible, and according to your normal-case scenario, it's easy to see how they could engage the AP at the routine time.
Of course all this only explains the pre-AP engagement phase.
If you're used to following the FD (normal for my plane) it's inconceivable to not notice that it's down in the dirt.
But if you're used to ignoring it, it's a much smaller gap to bridge from "it's somewhere down there in the blue" to "it's somewhere down there in the brown." Not noticing is now a lot more plausible, and according to your normal-case scenario, it's easy to see how they could engage the AP at the routine time.
Of course all this only explains the pre-AP engagement phase.
What you say is quit relevant, we are used to not follow the GA FD in case of take off or GO around with 2 engine, the FD when pressing GA is initial pitch for one engine ...
I was surprised about this comgic from a more advanced plane when I took my command ... But it is how the plane is designed ... And as said before there is a lot strangely designed in the dash 8.
Now I said that, still, I force myself to synchronise the pitch to the FD bar after acceleration before asking for the AP engagment and I also force myself to really read the mode FMA I see and not just what I think I pressed, it has saved my day more than once ... The dash is tealre basic, it will do what you ask for even if totally stupid.
A good example is when you go in IAS mode, my previous plane, if you had selected an altitude above and ask for a high speed climb with IAS mode but still at low speed when engaging, the plane would have level off, speeding up then resume climb with the speed requested, the dash 8 will start to descent (you ask for a high speed, so he want to reach the speed you want) then will climb when reaching the asked speed and realized you have lot of energy with engine and so can climb. Only way to no do that is avoided big speed change with IAS mode or monitor closely your engine set up (not auto throttle on the dash 8)
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We don’t normally wait and program in the departure at this late point, because there is too much to do with coordinating with ATC, ground crews, cabin crew, checklists etc to get away on time. What we do is put in what we expect from the filed flight plan coupled with experience and knowledge of the particular airfield.
Also before I retired the number of readback errors ( not picked up by atc) was increasing. Ie reading back what you expect & briefed rather than what was said.
Plummet would seem to be a very apt description here, given the evidence - very high RoD so close to the ground.
As for the rhetorical, indeed somewhat mocking question of whether the subject aircraft has a 'plummet mode': it would appear the answer is a resounding "YES". The questionable SOPs combined with the autopilot being able to be engaged with the FD bar 'on the ground', and the pilot choosing to engage autopilot with such obviously wrong FD command and failing to check the set altitude made this a very definite 'Plummet' mode.
The ability to engage the AP in this situation is of equal concern as the pilot's choosing to do so and then to fail to check it was doing what was expected. However the OP refers to their experience at Everett., implying experience of Boeing AP behaviour. Certainly the 737 AP will only engage if: a), the attitude is very close to the FD command, and b) there is negligible trim force on the column. Unless BOTH criteria are met, the AP will refuse to engage. It would appear that the design of the subject AP is not ideal, conspiring as it does with a pilot who fails to notice the daft FD command ,to spear the aircraft into the ground unless it is caught very quickly. Quite worrying.
Having read the report, I’m finding it difficult to understand how the situation was allowed to develop for as long as it did. I’m also sure that the crew did not set out to have an incident like this either, so there should be some learning points we can take away?
It is not normal on any departure to start descending soon after takeoff, unless something is going badly wrong. This seems to have been missed/ignored for what is a considerable length of time, given the ~1s reaction time we are meant to have approaching V1 and the initial climb out being what most would call a critical flight phase. All I can think of is that the PF/PM relationship broke down to the extent that no-one was actually minding the shop and/or projecting forward the aircraft trajectory. If the GPWS hadn’t gone off, one wonders how low they would have got or even worse.
Were they uncomfortable with what the aircraft was doing or was it only brought to their attention by a warning system? I fly a fairly computerised plane (777) but those first couple of minutes after departure you are concentrating hard on basic data and what the automatics are doing plus what modes they are in. I’d love to know what distracted the crew on this flight enough to end up in this situation, so I can avoid it myself...
It is not normal on any departure to start descending soon after takeoff, unless something is going badly wrong. This seems to have been missed/ignored for what is a considerable length of time, given the ~1s reaction time we are meant to have approaching V1 and the initial climb out being what most would call a critical flight phase. All I can think of is that the PF/PM relationship broke down to the extent that no-one was actually minding the shop and/or projecting forward the aircraft trajectory. If the GPWS hadn’t gone off, one wonders how low they would have got or even worse.
Were they uncomfortable with what the aircraft was doing or was it only brought to their attention by a warning system? I fly a fairly computerised plane (777) but those first couple of minutes after departure you are concentrating hard on basic data and what the automatics are doing plus what modes they are in. I’d love to know what distracted the crew on this flight enough to end up in this situation, so I can avoid it myself...
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Interesting incident.
Experienced crew on board, certainly the Captain, so I think its a bit quick to assume automation dependency.
If you consider no FMA annunciations, no GA, no ALT etc and just look at where the FD is?
Are the pink bars/mustache pointing to the sky?
No....
If its not pointing to the sky, its not correctly set. STOP and correct it.
Isn’t it the case however that when ‘we’ are feeling rushed, that is exactly the time to slow down, you know there will be errors, let us create the time we need to catch and fix them. Unfamiliar airport, tired from these preceding duties I would not be adding distractions with single engine taxi or other frivolous distractions.
TEM.
My biggest concern is that it took 15 seconds or so to notice the aircraft was not doing as it should be. Where was the scan, what were they doing? The PF’s eyes should be focused on the flight path and nothing else. PM should be backing him up, checklists can come later, much later.
Experienced crew on board, certainly the Captain, so I think its a bit quick to assume automation dependency.
If you consider no FMA annunciations, no GA, no ALT etc and just look at where the FD is?
Are the pink bars/mustache pointing to the sky?
No....
If its not pointing to the sky, its not correctly set. STOP and correct it.
Isn’t it the case however that when ‘we’ are feeling rushed, that is exactly the time to slow down, you know there will be errors, let us create the time we need to catch and fix them. Unfamiliar airport, tired from these preceding duties I would not be adding distractions with single engine taxi or other frivolous distractions.
TEM.
My biggest concern is that it took 15 seconds or so to notice the aircraft was not doing as it should be. Where was the scan, what were they doing? The PF’s eyes should be focused on the flight path and nothing else. PM should be backing him up, checklists can come later, much later.
Dancing with the devil, going with the flow... it's all a game to me.
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The AAIB report went into some detail to highlight the Commander's roster that week, which included being contacted prior to the start of his/her standby duty on the day of the incident to position in a taxi from ABZ to GLA (approximately a three hour journey). The report also mentions the Commander's previous days which included plenty of positioning, hotelling and a twelve hour duty.
Obviously they feel this is worth mentioning.
Just saying.
Obviously they feel this is worth mentioning.
Just saying.
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The clever Captain
Every airline has these guys , build you a clock instead of just looking at their watch .
Quite why he answered the ‘phone and has his rest disturbed. Is beyond me .
Why do Flybe feel it’s OK to contact people during their rest period ?
The real questions left un-answered
Every airline has these guys , build you a clock instead of just looking at their watch .
Quite why he answered the ‘phone and has his rest disturbed. Is beyond me .
Why do Flybe feel it’s OK to contact people during their rest period ?
The real questions left un-answered
If you want proper sleep, turn your phone off !
Or even easier and quicker; Set it to flight mode. Then the alarm will still work, but you won’t be distrurbed by any texts, emails or calls.
Or even easier and quicker; Set it to flight mode. Then the alarm will still work, but you won’t be distrurbed by any texts, emails or calls.
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Or use the ‘do not disturb’ mode which allows numbers you select (elderly parents etc) to get hold of you but mutes alerts, texts and calls from everyone else. I use it every day.
