https://simpleflying.com/airbus-a220-in ... ar-misses/


I thought the FAA was going to issue a separate AD for an issue the A220 has with the engines shutting down if you pull the power back too fast. Still interesting though.

It’s normal to engage any automation on ground roll?

CarlosSi wrote:

It’s normal to engage any automation on ground roll?

I mean, if you hit the TO/GA button on any Boeing aircraft it technically engages the autothrottle…

Same on the Collins, not sure why pilots are fiddling with the FGP on the roll, no need to.

I find it odd that pilots would be pressing buttons during the take off roll. If the autothrust is showing an error, set thrust manually and continue. (Odds are, takeoff thrust is already set). It’s just an airplane, autothrust/autopilot are cool, but you don’t need them to fly the aircraft safely and certainly not when barreling down the runway.

But, to be banging away at the FCP in a panic somewhere between “Thrust set” and “V1/rotate”, not sure of what you’re setting, is folly.

KPTKRampy wrote:

CarlosSi wrote:

It’s normal to engage any automation on ground roll?

I mean, if you hit the TO/GA button on any Boeing aircraft it technically engages the autothrottle…

Right but is it normal procedure to engage it during the ground roll? I’m no 737 pilot so it baffles me why one would even touch AP or AT on ground roll and mistake one for the other.

When anything automated goes afoul, just fly the aircraft, and figure out the automation issue when it's safe to do so. Basic airmanship. "Chidren of the Magenta" comes to mind.

It reminds me a lot of the early days of the A320 FPA/VS confusion. It was cited in a factor of an Air Inter crash.

The solution was two-fold. Firstly to remind pilots to be sure of what vertical mode they were using and secondly, to change the display slightly to remind the ones that didn’t.

Training? Sure. How about keep your fat fingers off the FCP during the takeoff roll. Also, fly a few sim sessions with the autothrust and autopilot off, reminding pilots that in fact, they are not necessary. And never necessary during the takeoff roll.

It’s the old saw about trying to make something foolproof. Nature will always design a more capable fool.

I would imagine these issues have already been addressed at airlines flying the A220. Not to mention, it’s likely addressed during recurrent training. These industry issues are shared among operators. Standards and Training are the departments that act on them first.

CarlosSi wrote:

KPTKRampy wrote:

CarlosSi wrote:

It’s normal to engage any automation on ground roll?

I mean, if you hit the TO/GA button on any Boeing aircraft it technically engages the autothrottle…

Right but is it normal procedure to engage it during the ground roll? I’m no 737 pilot so it baffles me why one would even touch AP or AT on ground roll and mistake one for the other.

The auto throttle on the 737 is normally “armed” while setting up at the gate. This means that the mode appears white on the FMAs (Flight Mode Annunciation above the primary flight display) the auto throttle “activates” when the TO/GA button is pushed during thrust lever advancement. It then sets the takeoff thrust and the PM makes sure the engines are producing +1% to -0% of planned N1 engine thrust.

Caspian27 wrote:

CarlosSi wrote:

KPTKRampy wrote:

I mean, if you hit the TO/GA button on any Boeing aircraft it technically engages the autothrottle…

Right but is it normal procedure to engage it during the ground roll? I’m no 737 pilot so it baffles me why one would even touch AP or AT on ground roll and mistake one for the other.

The auto throttle on the 737 is normally “armed” while setting up at the gate. This means that the mode appears white on the FMAs (Flight Mode Annunciation above the primary flight display) the auto throttle “activates” when the TO/GA button is pushed during thrust lever advancement. It then sets the takeoff thrust and the PM makes sure the engines are producing +1% to -0% of planned N1 engine thrust.

That’s exactly the same on a Collins system—arm A/T, shows white as armed, on he runway advance the throttles and the system takes control at a certain thrust setting and sets selected takeoff thrust. Or use the TOGA button.

There’s no reason to be fingering the FGC during takeoff—training and checking problem.

The issue is obvious when looking at the autopilot panel:



The A/P and A/T push buttons are on top of each other, rather small, look exactly the same and even their labeling only differs by one letter...

This is a design disaster in terms of ergonomics and safety. I'm surprised this passed design review in the first place.

As the article said, there is not much they can do now unless Airbus decides to redesign the panel and recertify it, which they'll try to avoid as much as possible of course. Awareness will be raised during regular training and hopefully it reduces incidences to an acceptable level.

That’s weird, the G7500 and earlier G6000 have nearly identical panels EXCEPT we don’t have an AT button.

Do the G6000 have it? They seem to have the same p/b layout as the A220.

Also, what is the guarded switch below the AP / AT / FD(?) switches? It's hard to tell from the pictures.

Francoflier wrote:

Also, what is the guarded switch below the AP / AT / FD(?) switches? It's hard to tell from the pictures.

EDM, Emergency Descent Mode

Francoflier wrote:

The A/P and A/T push buttons are on top of each other, rather small, look exactly the same and even their labeling only differs by one letter....

Which is why one should be very careful which button they are pushing, not just flailing around in a blind panic. Especially during a critical phase of flight, when there is absolutely no reason to be pressing anything on that panel.

Francoflier wrote:

...As the article said, there is not much they can do now unless Airbus decides to redesign the panel and recertify it, which they'll try to avoid as much as possible of course. Awareness will be raised during regular training and hopefully it reduces incidences to an acceptable level.

I am not seeing where the switchgear in question is in this picture.

That said, would it not be a hell of a lot easier to change the shape/type of switches under an AD? Make one a red rocker*, the other a black paddle switch?

*Sammy Hagar approved

Francoflier wrote:

Do the G6000 have it? They seem to have the same p/b layout as the A220.

Also, what is the guarded switch below the AP / AT / FD(?) switches? It's hard to tell from the pictures.

Nope, no AT button on any of the Collins Globals

Pontiac wrote:

Francoflier wrote:

...As the article said, there is not much they can do now unless Airbus decides to redesign the panel and recertify it, which they'll try to avoid as much as possible of course. Awareness will be raised during regular training and hopefully it reduces incidences to an acceptable level.

I am not seeing where the switchgear in question is in this picture.

That said, would it not be a hell of a lot easier to change the shape/type of switches under an AD? Make one a red rocker*, the other a black paddle switch?

*Sammy Hagar approved

Right in the center of the FGC, between 227 and 9900 and above the red guarded switch.

No, that’d be impossible. I don’t see why there’s an AT button. There is Engage/Disengage buttons on the throttles on the Globals.

GalaxyFlyer wrote:

Pontiac wrote:

Francoflier wrote:

...As the article said, there is not much they can do now unless Airbus decides to redesign the panel and recertify it, which they'll try to avoid as much as possible of course. Awareness will be raised during regular training and hopefully it reduces incidences to an acceptable level.

I am not seeing where the switchgear in question is in this picture.

That said, would it not be a hell of a lot easier to change the shape/type of switches under an AD? Make one a red rocker*, the other a black paddle switch?

*Sammy Hagar approved

Right in the center of the FGC, between 227 and 9900 and above the red guarded switch.

No, that’d be impossible. I don’t see why there’s an AT button. There is Engage/Disengage buttons on the throttles on the Globals.

In the centre ofthe FCP, from top to bottom: AP (with green engagement light above), AT (with green engagement light above), XFR toggling the left/right arrows then the guarded EDM switch (with a red warning light above).

There is no engagement button on the thrust levers, only an autothrust disconnect button. So, the AT button on the FCP would be to re-engage the AT system in flight.

CrewBunk wrote:

GalaxyFlyer wrote:

Pontiac wrote:

I am not seeing where the switchgear in question is in this picture.

That said, would it not be a hell of a lot easier to change the shape/type of switches under an AD? Make one a red rocker*, the other a black paddle switch?

*Sammy Hagar approved

Right in the center of the FGC, between 227 and 9900 and above the red guarded switch.

No, that’d be impossible. I don’t see why there’s an AT button. There is Engage/Disengage buttons on the throttles on the Globals.

In the centre ofthe FCP, from top to bottom: AP (with green engagement light above), AT (with green engagement light above), XFR toggling the left/right arrows then the guarded EDM switch (with a red warning light above).

There is no engagement button on the thrust levers, only an autothrust disconnect button. So, the AT button on the FCP would be to re-engage the AT system in flight.

And that’s what I don’t understand—why didn’t the design just use throttle installed ENG/DISENGAGE switches?

GalaxyFlyer wrote:

And that’s what I don’t understand—why didn’t the design just use throttle installed ENG/DISENGAGE switches?

It’s funny. When you were describing the system above, I was thinking to myself how much easier it would be to have an engage switch on the thrust lever itself. I don’t know how many times I’ve engaged the autothrust system with one hand, held onto the thrust levers with the other hand (I’m old school, guarding them from doing something strange) with my third hand on the yoke!

I don’t know why that design wasn’t used. I’ve flown all Airbuses from A300 to A340, 737, 767, DC-10 and E175/190. (Yeah, I’m retiring soon). None of them had a system any different than what I described. Disconnect on the thrust levers, re-engagement on the FCP.

Pontiac wrote:

That said, would it not be a hell of a lot easier to change the shape/type of switches under an AD? Make one a red rocker*, the other a black paddle switch?

*Sammy Hagar approved

Reminds me of an old report I once read, an early B727 crash. The NTSB pointed out that the handles for flaps and wheels were close to one another, and felt the same to pilots (who had inadvertently retracted flaps at lift off instead of the intended landing gear, iirc). The handles were re-designed so that they could be easily distinguished.

In this case, could the softwear be modified to provide some form of visual notice / warning to draw attention to the engagement of AT or AP? Strikes me that this would be an easy short-term solution (or, at least a partial solution)?

On the Globals, which is nearly identical and also Collins, you arm TO with the side-mounted TOGA buttons, the cue sets at a set pitch angle. AT is armed, line up, cleared to roll, press the rear buttons on either throttle to ENG AT and away you go. If you want, advance the throttles and at 60 (or 80) knots, the throttles take over and set thrust. Either way, no need to touch the FGP (Flight Guidance Panel). If you don’t want AT, just advance the throttles. Why not on the A220, née C-Series, I can’t say.

YYZYYT wrote:

It would be easier to explain procedural use of the autothrust system:

During initial cockpit scan, the AT button is pressed. This arms the system, and a white AT is annunciated on the FMA indicating that it is armed and functional.

During takeoff, the thrust levers are advanced by hand, (standing first at 50%N1, making sure they come up evenly) then further. As you pass 23° of thrust lever angle, approximately 68%N1, the autothrust system takes over and advances the thrust levers to the preset takeoff thrust. The white AT annunciation turns green. Nothing to do until climb thrust after takeoff.

What occurred in these incidents, is the autothrust system failed during takeoff. AT Fail comes up on the EICAS and the AT annunciation turns amber. Pilot action? Nothing! (Other than glancing at the engine instruments to confirm you still have takeoff thrust).

Continue the takeoff and set climb thrust by hand at acceleration altitude. It is that “fear” of selecting climb thrust by hand, that would lead a pilot to try re-engaging the AT button on the FCP in a panic during the takeoff run. Hitting the AP button instead.

That is why this is a Training/Standards issue. Train pilots not to touch the FCP during takeoff. Give the pilots practise in operating without the autothrust system, alleviating that “fear”.

Yes, the two switches are close. But, with correct operation of the aircraft, mistaking one for the other will not be critical, with lots of time to correct your mistake.

Is it possible to lockout the autopilot on the takeoff roll, or below 400 feet? Or is that not desireable for some reason?

It is a FBW design. Therefore, it is easier to implement a SW lock to inhibit the engagement of AP on ground than redesign the panel.

Avatar2go wrote:

Is it possible to lockout the autopilot on the takeoff roll, or below 400 feet? Or is that not desireable for some reason?

The Auto pilots on Boeings cannot be engaged below 400’ on the 787 it’s 200’. If you try you get an AP wailer.

CriticalPoint wrote:

Avatar2go wrote:

Is it possible to lockout the autopilot on the takeoff roll, or below 400 feet? Or is that not desireable for some reason?

The Auto pilots on Boeings cannot be engaged below 400’ on the 787 it’s 200’. If you try you get an AP wailer.

Same thing on what I fly, the A330. 400’

Just had this question pop into my head, Airbus’ own aircraft has a feature on the throttle pedestal, where you position the throttle levers over a detent (?), you press then autothrottle button on the A/P control panel and the autothrottle takes over. Did airbus add that feature to the aircraft when they took over the program?

Thanks everyone for the responses. So perhaps the lockout can be a possible longer term solution on the A220 as well. That wouldn't be a focus of the EAD, which is just to prevent an accident.

CarlosSi wrote:

KPTKRampy wrote:

CarlosSi wrote:

It’s normal to engage any automation on ground roll?

I mean, if you hit the TO/GA button on any Boeing aircraft it technically engages the autothrottle…

Right but is it normal procedure to engage it during the ground roll? I’m no 737 pilot so it baffles me why one would even touch AP or AT on ground roll

Everyone takes off with AT’s armed. 737’s, E190’s, A220’s… totally normal. If the AT disengages for whatever reason, SOP is to just push the throttles to max power and continue the takeoff. You’re not supposed to be reaching for the FCP on a takeoff roll.

KPTKRampy wrote:

Just had this question pop into my head, Airbus’ own aircraft has a feature on the throttle pedestal, where you position the throttle levers over a detent (?), you press then autothrottle button on the A/P control panel and the autothrottle takes over. Did airbus add that feature to the aircraft when they took over the program?

Very different systems, the A220 uses “moving” levers, rather than detented levers. It was designed that way by BBD, certified that way, big move to change it.

FYI, there are some airplanes that require you to push an "Auto Flight" button on the FCP on takeoff roll to engage the Auto thrust/throttle: the 717 and MD-11 for example.

fly4ever78 wrote:

FYI, there are some airplanes that require you to push an "Auto Flight" button on the FCP on takeoff roll to engage the Auto thrust/throttle: the 717 and MD-11 for example.

the 757/76 requires you to push the AT/EPR button on the MCP.

SPREE34 wrote:

When anything automated goes afoul, just fly the aircraft, and figure out the automation issue when it's safe to do so. Basic airmanship. "Chidren of the Magenta" comes to mind.

Bingo….

CarlosSi wrote:

KPTKRampy wrote:

CarlosSi wrote:

It’s normal to engage any automation on ground roll?

I mean, if you hit the TO/GA button on any Boeing aircraft it technically engages the autothrottle…

Right but is it normal procedure to engage it during the ground roll? I’m no 737 pilot so it baffles me why one would even touch AP or AT on ground roll and mistake one for the other.

Yes on some A/C.....

The 220’s AT’s are typically armed at the gate and are also very sensitive. I’ve noticed when pilots coming from other types first start flying the 220, they can be a little aggressive when setting take off thrust. This will automatically shut off the AT’s with a warning. Our company policy is to set max takeoff thrust and continue the take off. We have been specifically instructed to NOT try and reengage the AT’s until we’re at a safe altitude due to the close proximity of the AT and AP push buttons. In my opinion, It’s really not a big issue - as others have said - just fly the airplane, but I could see how the shock factor could cause some serious issues.

CrewBunk wrote:

Francoflier wrote:

The A/P and A/T push buttons are on top of each other, rather small, look exactly the same and even their labeling only differs by one letter....

Which is why one should be very careful which button they are pushing, not just flailing around in a blind panic. Especially during a critical phase of flight, when there is absolutely no reason to be pressing anything on that panel.

Humans make mistakes. I think it's unrealistic of you to sit here and call them idiots and suggest that they NOT do what led to the issue as if they consciously made the mistake.

Stacking the AP and AT buttons together like that is poor design. That needs to be remedied.

Surely the bigger issue here is that the CSeries/A220's autopilot can apparently be engaged on the ground? Why doesn't it have a 400ft minimum engagement height?

KPTKRampy wrote:

Just had this question pop into my head, Airbus’ own aircraft has a feature on the throttle pedestal, where you position the throttle levers over a detent (?), you press then autothrottle button on the A/P control panel and the autothrottle takes over. Did airbus add that feature to the aircraft when they took over the program?

I doubt Airbus had anything to do with that design. They took over the program much too late to make these kind of design changes.

My guess as to why it's different from BBD's business jet offerings (as described by GalaxyFlyer above) is that they wanted to make the design closer to almost every other airliner, which tend to have an A/T engage p/b on the FCP instead of on the thrust levers. It seems to have been a fairly daft implementation however.

As for why it is possible to engage the autopilot on the ground or very close to it, I'm not sure. Maybe they were planning on adding an auto-takeoff function down the line?

Add to all that the fact that any slightly hurried movement of the thrust levers will apparently disconnect the A/T (as per Poorpilot's post above... another puzzling feature) and all the elements for a screwup are there.

As said above, it sounds like a relatively easy software fix, although it would require certification and a slight amendment of manuals and training programs.

PhilMcCrackin wrote:

Stacking the AP and AT buttons together like that is poor design. That needs to be remedied.

I have a surprise for you ….. so are the AP and AT buttons on the A320 (A318, A319, A320, A321), A330 and A340. On the 767, 777 and 787, they are about an inch apart.

It is SOP where I fly, on all that the AP and the AT can not be engaged below 400’. (Including the A220). It is also included in the limitations noted in the Flight Crew Operating Manual. (Slightly different on the 787/777 but we use 400’ for fleet commonality).

We currently have 31 A220s. To date, this has never occurred on any of our aircraft. I would be curious therefore how the series of events played out at other carriers where the pilot felt the need to press any Flight Control Panel button during the take off roll.

The ATB issued to the pilots outlining this issue and Transport Canada’s EAB, is 6 pages long. I hope all pilots who fly the A220 respect it.

PhilMcCrackin wrote:

Humans make mistakes. I think it's unrealistic of you to sit here and call them idiots and suggest that they NOT do what led to the issue as if they consciously made the mistake.

Understand that the “mistake” was not pressing the wrong button, but pressing any button when it is not even remotely necessary. Keeping one’s fingers off the FCP would solve the “mistake”.

Francoflier wrote:

Add to all that the fact that any slightly hurried movement of the thrust levers will apparently disconnect the A/T (as per Poorpilot's post above... another puzzling feature) and all the elements for a screwup are .

This is the first I had heard of this. But, proper thrust lever handling requires somewhat slow movement during the start of advancement toward takeoff thrust. Up to around 50% N1, the thrust may not advance at the same rate.

So that you don’t have asymmetric thrust, it is suggested to stand the thrust up at 50%N1 first, make sure they are matched, then advance them further, for symmetric thrust. If you just bang the thrust up quickly ‘cause it feels cool, you may end up with quite a handling issue! I could see where the AT system detecting asymmetric thrust might shut down.

For fun, we tried it in the simulator (A330), just to “see”. Just pushed the thrust levers to takeoff thrust quickly, without stopping at 50% first. From 33L at YYZ, it was quite a ride! We ended up at the Starbucks in the domestic end of T1. (Grande bold please).

CrewBunk wrote:

PhilMcCrackin wrote:

Stacking the AP and AT buttons together like that is poor design. That needs to be remedied.

I have a surprise for you ….. so are the AP and AT buttons on the A320 (A318, A319, A320, A321), A330 and A340. On the 767, 777 and 787, they are about an inch apart.

It is SOP where I fly, on all that the AP and the AT can not be engaged below 400’. (Including the A220). It is also included in the limitations noted in the Flight Crew Operating Manual. (Slightly different on the 787/777 but we use 400’ for fleet commonality).

Yes, but the buttons are dissimilar enough that missing the A/T button with your hand majorly reduces your chances of accidentally engaging the A/P. With the 2 A/P buttons on the Airbus and the single A/T button between them, it's likely your finger would just hit the gap between the two A/P switches and not engage either. On the Boeings, with the A/T switches being rockers and the A/P switch push buttons, the hand motion to flip a rocker avoids this problem. What the poster expresses (and what was stated earlier upthread) is that these two switches are 1) in exact alignment with each other, allowing your finger to skip or stab and hit the wrong one, and 2)they are both the same kind of activation mechanism (a push button) so making the same gesture for both also and accidentally hitting the wrong doesn't set off your spidey senses as having hit the wrong switch when manipulating the automation.

Interesting. Have had this happen a couple times on takeoff in the 220 (admittedly new-ish to the type). ATs are armed for takeoff, however the throttles are very touchy and can be fairly easily deactivated. Can understand how the two buttons can be easily confused, however I never once considered reaching up to re-engage on the roll. Set max thrust and fly the throttles in manual until after takeoff.

FlyingBrit wrote:

Interesting. Have had this happen a couple times on takeoff in the 220 (admittedly new-ish to the type). ATs are armed for takeoff, however the throttles are very touchy and can be fairly easily deactivated.

That's the part I don't quite understand. Does the A/T disconnect because of jerky thrust lever movement or because of accidental pushing of the A/T disconnect switch while operating them?

Francoflier wrote:

FlyingBrit wrote:

Interesting. Have had this happen a couple times on takeoff in the 220 (admittedly new-ish to the type). ATs are armed for takeoff, however the throttles are very touchy and can be fairly easily deactivated.

That's the part I don't quite understand. Does the A/T disconnect because of jerky thrust lever movement or because of accidental pushing of the A/T disconnect switch while operating them?

Not an A220 pilot so dont have direct experience.

Engines will spool up at different rates due to age, component wear, and a bunch of other factors, especially at lower speeds. The most common reason an A/T system would disconnect is when asymmetric thrust is detected between the engines. So if throttles are advanced rapidly from idle and the engines spool up at different rates the A/T detects asymmetric thrust and disconnects. This system seems to be very sensitive on the A220 and requires a slow advance from idle to prevent an asymmetry detection event.

Maybe a possible fix is to increase the asymmetry threshold so that A/T disconnects are less common.

They aren’t getting deactivated. They aren’t being armed for takeoff period.

It’s not noticed until you bring the thrust up through 60% N1 and you realize A/T isn’t taking it from there. It’s just a simple whoops moment where the pilot monitoring just sets appropriate thrust manually.

Unfortunately some crews are trying to salvage the situation by engaging AT during TO roll at relatively high speeds. There’s more problems with just accidentally engaging AP, the autothrottle may not set thrust to the proper flex setting.

NOTE: There have been a few off-topic posts deleted referencing the 737MAX and how long the FAA took to ground it. The topic of this thread is clearly about the A220’s auto-throttles, and not the 737MAX grounding.

This will serve as a general warning: stay on topic.

24Whiskey wrote:

They aren’t getting deactivated. They aren’t being armed for takeoff period.

It’s not noticed until you bring the thrust up through 60% N1 and you realize A/T isn’t taking it from there. It’s just a simple whoops moment where the pilot monitoring just sets appropriate thrust manually.

Unfortunately some crews are trying to salvage the situation by engaging AT during TO roll at relatively high speeds. There’s more problems with just accidentally engaging AP, the autothrottle may not set thrust to the proper flex setting.

This, a hundred times. I still don’t see, based on Collins experience, why they out that button there and why the button exists. TOGA to set the pitch cue and arm the AT, ENG switches on the throttles on line-up, advance them to about 60% and job done. If the crew selected AT late, at 80 knots, the system goes into HOLD and holds whatever thrust is set at that moment. Likely much less than required.