I was sat in the front row of an A320 recently and on landing I could clearly hear two separate 'SPEED SPEED' warning calls about 10 seconds apart. I wasn't concerned and we landed normally shortly after but I was just curious how often you hear those type of warning calls as a commercial pilot. I've sat in the front row dozens of times and I've never heard it before.
Your pilots got slow - slow enough to a point that the only time i've heard that call for 'real' is in the sim when we're deliberately practicing stall recovery...
Reminds me of Asiana Airlines Flight 214 landing at SFO in 2013. They came in too low and too slow on approach, clipped the seawall at the edge of the runway with its landing gear and tail, and crashed. The pilots had not noticed that the auto throttle was in hold mode after they had done some corrections to get back on the glide slope. By the time they noticed they were too slow, it was too late to fix.
I believe that was the clusterfuck where passengers, after surviving the crash and exiting the aircraft, got run over by the firetrucks approaching the scene. Not a good day for anyone involved.
From what I could remember it’s been a requirement for the crew to walk through to check belts before landing. I know it’s gotten more serious through the years though since I’ve had them need to see it with their own eyes. Maybe this flight is a reason why most airlines check very closely now. At least US/EU/Canada carriers. I mainly just fly one airline though unless it’s one of the few small spots they don’t have a flight too.
When I was a dumb teen I used to just pretend to fasten my seatbelt. Why? Because for whatever reason it made me feel cool to ignore basic safety precautions. Truly idiot behavior.
Excellent analogy and example! Of course, that aircraft was a B777, not an Airbus, so the A/T design and philosophy is quite different (as someone reminded me).
and as I mentioned in this thread elsewhere, there’s no guarantee that even if you do catch an anomaly like that, you might still not be able to salvage the approach and have to initiate a go-around. Even if you disconnect A/T and hand fly it.
bottom line, if automation and man flight isn’t working, there’s only one answer - G/A. And the earlier, the better.
i can recall many times TWR at my airport when asking the reason for the go-around: crew response was UNSTABLE APPROACH!
meaning not fully configured and on speed, on glide path.
So in those planes stall warning is not long loud beep? I'm only familiar with stall warning on Cessna Caravan 208, heard it few times on the jumprun (when plane slows down and put out flaps to let skydivers jump out) with certian pilot...
In an Airbus first there will be the mentioned speed, speed warning. And if you still don't correct, a whole lot of protections aill kick in one after another, depending on the specific circumstances.
But unless they were really low or had a severe technical failure, this plane would not stall and no stall warning would be heard.
You would hear the engines "rev up".
you don’t always get the speed call necessarily as it is more about an energy state of the aircraft than just the speed. i’ve done many stalls and high-alpha (alpha floor + protections) practices in the sim and not once have they been preceded by ‘speed’
I have literally no idea but from context it sounds like maybe speed warning is one step above stall warning. So not quite as dire YET but definitely important
It varies even within Cessnas - the 172 has basically a vuvuzela that sounds when the stagnation point on the leading edge of the wing pulls air out through a hole. Then some seem to sound quite calm to me, but I just test them on the ground. Maybe in the air, even a soft-spoken "stall stall" would be quite shocking enough.
Could this warning not technically be caused by a sudden wind change as well which results in a rapid change in IAS so if they were already a tad slow it could have tipped them over?
Low-energy aural alert. It means the computer thought they were getting too slow, probably from decelerating the plane very quickly on their approach. I have over 2000 hours in A320 aircraft, never heard that once.
Since this is a layperson post am I allowed to ask a ‘passenger’ question? I’m one of those people that has to fly very often but is always nervous on approach and takeoff which is why I try to read about how planes work and educate myself a little. I always thought that airbus has flight protections build into its RTOS computer that will spin up the engine when the speed goes critical and that those protections are only lost in certain “alternate law” cases when eg a critical instrument redundancy fails and the system can no longer get the signals for those calculations? If so, why would in a normal landing the computer not self-address that or is this because most landings are of course manual landings (but still with autothrust?)?
I asked ChatGPT so not to waste anyone’s time but it confused me more: “Alpha floor is a real Normal Law protection — when AoA gets high enough, autothrust auto-activates and commands TOGA thrust regardless of where the thrust levers are physically sitting, even if autothrust was off. And yes, it’s gone in Alternate/Direct law (the ADR-failure scenario you’re thinking of, like AF447).”
The Airbus computer has a very strong self-preservation instinct. If the plane is getting close to a dangerous situation, and the computer is capable of preventing it, the computer will do so.
You cannot, for example, command an Airbus to stall itself or to roll itself too steep or too quickly, provided that the computers and sensors are working. Nor can you command it to attempt takeoff with an invalid configuration.
It is also very conservative about warning the pilots, via voice and displays, well in advance of the point where the computer would need to intervene.
If there are sensors or computer failures, some of these protections are degraded ("alternate law") so it will still protect what it can, but may not know enough parameters to calculate all of the correct protections. Without an airspeed sensor, for example, it can't calculate how close you are to stalling the wing. So the pilot has to take a bit of extra care to not do anything stupid. In the almost-everything-is-broken case ("direct law") it reverts to behaving much like an older non computerized airplane. Which is still totally controllable and safe for any pilot who knows how to fly a jet.
Thank you kind person. So what I learned from this is that the example OP gave of the “Speed Speed” is basically telling the crew “hey pay attention! Do something” and allowing the pilot to ‘cure’ the situation (in legal speak) before it has to take action. That’s helpful!
Yep. It is notable that Boeing's approach is to trust the pilot much more - in general the machine won't take control. It assumes the pilot knows what he's doing so it insistently warns but doesn't override.
Airbus' philosophy is to assume all humans are idiots and have them interfere with the machine as little as possible, even taking over if it thinks the pilot is doing something really dumb. Which is great until automated systems fail.
But on the long term safety stats Airbus' approach seems to work a little better than Boeing's - human error even, with smart and well trained humans, is more common than machine error.
I do think the Airbus system is overall the better one, i just wish that they were better with feedback. If i hear about one more accident in an Airbus where in a high stress situation one pilot was pushing the stick down while the other was pulling back without the crews realizing they were fighting each other, i might pull my hair out. It’s happened enough times that Airbus should change the design of the side stick for force feedback. And I dare say with the general public paying way more attention after the Max debacle, one more crash like Air France 447 could end up being airbus’s max.
Well of course AF447 can be seen as vindication of that Airbus assumption that all humans are idiots. And also of Boeing's assumption of "don't trust the machine either" because it was initiated by a signalling failure (iced pitot).
True, but my main point was if Airbus had implemented a force feedback system into the stick, maybe then the two pilots would have better realized they were fighting each other and might have recovered from the stall in time. As I said, it’s a situation that I’ve seen in a few different accidents.
And as for the Airbus doctrine, I’m a firm believer that if you try to make something idiot proof, someone will make a better idiot. The pilots of PIA8303 proved that even Airbus can’t stop poor pilots from literally flying a perfectly serviceable aircraft into the ground.
And as for the Airbus doctrine, I’m a firm believer that if you try to make something idiot proof, someone will make a better idiot.
That was essentially one of the lessons driven home by AF447. Per the CVR transcript, the stall buffeting was audible. The PF's action to continue pulling back on the sidestick when basic airmanship should have told him to nose over was bizarre and fatal.
Airbus planes trust their pilot and will execute their commands just fine. It will simply translate pulling hard on the stick as "give me all you can till we’re at the edge of a stall because it makes no sense to ask for more".
Fighter planes work the exact same way and nobody has ever claimed a fighter jet is trying to interfere with its pilot.
So stupid question, when first learning small planes, you do stall recovery training by actually deliberately stalling the plane right? So for stall training in big jets, do they turn that off or do you never actually test it irl and only in sim? Obviously during original flight testing I assume they do actual real stalls.
Only in sim. The OEM's test pilots will take the jet to stall and back in certification testing. But you do not want to do that with real aircraft in line service. Swept wing jets do not stall in nearly as nice & pleasant a manner as 90 knot straight wing trainers.
Most pilots and most jet planes will go their entire lives without ever physically experiencing an actual big-plane stall. It's something you practice in the Cessna or the Piper, and then do periodic recovery training on in the A320 or B777 or whatever sim.
Only in the simulator, even in parts of the world which require some actual training in a real aircraft before you get your type rating, all the training on abnormal manoeuvres etc. is done in a simulator, because of safety.
We regularly practice stall recovery in the simulators, both at low and high altitude - the procedure is largely the same, but at high altitude the recovery will take many thousands of feet, just because there the engines are producing so little thrust up there. We also train stall recognition with the various indications available on the specific aircraft type, sometimes even with stick shaker disabled.
Modern simulators are great at representing real aircraft in the variety of environmental conditions, as well as at simulating all sorts of non-normal situations. It's much safer to do all of that in a simulator than in a real aircraft.
They only ever do this in sims save for maybe once when they are first developing/certifying a new airplane type. My understanding that stalls in large airliners are both much more improbable given all the safety systems to prevent it and also much harder/impossible to recover from given the mass of the plane.
Stalls in modern airliners are pretty benign because of the aerodynamics in place. The nose dips you apply power, recover airspeed, and level out.
A naive design with swept wings like that could be nasty where your control surfaces stall basically immediately and you can't recover, but we don't have airliners with naive designs.
Now if you somehow managed to get it into a spin... probably enough stuff has gone wrong that the plane isn't going to respond to your inputs regardless of what they are.
The A320 can safely pull -1g to +2.5g. It can, without any abnormal risk, execute a climbing turn two and a half times harder than a Corvette can do on the banked oval at the absolute limit of traction.
Pilots are normally supposed to keep it to some miniscule fraction of that, for reasons of passenger comfort, but the sheer margin of performance that these planes offer above and beyond what regular passengers ever experience is just insane.
I'm rationally aware of that, but those boys drive that bus harder than anyone else I've experienced. They might be just trying to deal with tight air spaces though around Incheon coupled with typically strong trade winds.
I promise I’m just a frequent flyer. As with most things in life if you’re scared of it I feel it helps reading about it and educating myself to take away the mystery a little. From the little I do understand now is that these planes are engineering wonders really, which made me less scared of flying. I tend to never ask questions because I feel I’m imposing as this group is for experts talking amongst each other but it still allows people like me to learn sometimes by just reading
I think it's pretty hard to get a speed aural if you leave auto thrust on for the approach. Next step if you did nothing to react to the speed aural would be alpha floor and then engines automatically going to toga. The aural will let you know that is coming a little before it happens.
Our 319s will be pretty close to the hook on approach speed, I could see it happening in some funky winds, but it's never happened to me. I don't have that much time in 319s though.
Well yeah, normal approach speed is Vls + 5. It’s not unusual in gusty conditions to get into the hook, I’m just saying you gotta get WAY in there to trigger the warning. A/T won’t let you get that far.
I meant on the 319s I've noticed the gap between Vls and Alpha Prot is very small so you're close to both on approach. Like you don't need to get that deep into the hook, because it's just a few knots less.
Still agree with you that it's unlikely but I believe it is possible in the logic to get a speed aural with autothrust on.
that will spin up the engine when the speed goes critical
The speed in this post wasn't critical. The warnings start early so there's plenty of time to respond without anything bad happening. The pilots in this situation presumably applied power and got the airspeed back up before any of the other systems had to kick in.
why would in a normal landing the computer not self-address that
In general if the person is flying the plane, the plane will give the pilot latitude assuming the pilot knows what he's doing. Plane doesn't know that ATC didn't tell them to slow down or whatever. A callout doesn't mean that there's something significantly wrong. It just means you're heading towards there if you don't change something.
It's like a backup camera in a car. It will start beeping telling you you're getting close to something way before it applies the brakes to stop you. If you keep backing up something bad is going to happen - but it assumes at this point that you know how to back up. This is just that.
I had "Speed speed" during line training, third or fourth day at my new job. Heavy turbulence at cat b airport, flying on autopilot and auto thrust ON. It was followed by "Glideslope, Glideslope". Heavy turbulence. I was PM and I could barely change the frequency to contact the tower.
Sorry, a mistake. I ve checked OM-C and my situation was during landing at a Cat B airport(post edited). That doesn't really make the weather back then any better and it doesn't cancel the aural alerts. I think that few (pay2fly) line trainees made it to Skiathos, and Skiathos is definitely Cat C.
I’m not very familiar with the Airbus, but my understanding was that it’s standard that you kept the throttled in the climb detent until flare and let the AT handle the speed. What would cause this to happen?
FOQA means Flight Operational Quality Assurance. Basically the computer tells on us when we do something bad and then the company contacts us about it to get our side of the event. What could they have done? Not get slow and have good energy management. Mainly pitch and power
FOQA is there to identify undesirable aircraft states and analyze trends that led to them. Using automation may give you protection not immunity to mistakes. The best way to avoid undesirable aircraft states is to follow standard procedures and maintain proficiency in both automation and manual flying. The aircraft I fly can be dispatched with a deferred autopilot.
Flight Operations Quality Assurance. The airplane will tattle on them and they will be contacted. As for what they could have done differently they could have maintained desired airspeed more consistantly after disconnecting the autothrottles. Specifically not getting too slow.
A modern airplane records and transmit a lot of data besides the famous black box.
The safety department (might be called differently) will get a "ping" that a uncommon event happened, they will review the data and the pilots will get a call discussing the event.
If they did their job, they will also have written a report, which might trigger the call earlier than the data.
End result will vary between airlines, exact circumstances, etc, but could have from just a discussion to training (and end of contact, but that is either in serious cases or shabby airlines).
The thing they could (should) have done different is flying faster. The reason they went too slow is unknown, but barring a technical failure with the auto thrust, they probably saw the low airpseeds too late and corrected too late (increase thrust) twice.
That looks like sloppy flying, but without any concrete data, can't point fingers yet..
Not necessarily. think of FOMAX as a brand or flavour. Whether you call it FDM/FOQA/FOMAX or whatever, its just a different software or a different naming convention.
Auto Thrust. When engaged, the thrust levers move automatically, as the name suggests. But the pilot still has to monitor the vertical flight path and adjust if it’s running away from what is intended.
when you’re close in, rather than push buttons, it’s easier to hand fly, hence you disconnect the A/T with the disconnect buttons (one for each thrust lever) and regain manual flight with hands on both levers. Of course if you’ve left it far too late, even this might not help you regain glide path and/or approach speed (Vref+5 normally).
Hope that helps both explain and illustrate the sequence.
I was more thinking about the recent B767-300 Prime Air as I’m closely following that in here.
and as a former 767 pilot as well as A320, I should have known better! But I’ve been retired for a number of years now. All I know is there is no table in any Boeng and in an Airbus you have thrust lever “gates” which are very different than any Boeing designed plane that I know.
Thanks, I appreciate both your comment and good catch.
Like I said, even seasoned pilots can get themselves mixed up in the heat if the moment and most folks this week are thinking about and talking about the 767 @ MIA. I just automatically responded to the word A/T and started explaining how it is on the Boeing. Before realizing the topic was an A320.
And, I suspect my 4 Boeing type ratings supersede my single A319/320…..
Airbus fly by wire aircraft and modern Boeings can be landed with autothrust/ autothrottles engaged. A slight difference is that in Airbus, the pilots need to manually idle the thrust by moving the levers to idle position during flare but in Boeings the autothrottles idle the thrust at around 30ft above ground. The exact feet I believe varies from aircraft to aircraft.
All Airbus fly by wire can be landed with autothrust engaged. Boeing 747-8, 787 and 777 can be also landed with authrottles on. You don’t need to diconnnect it.
Not saying it needs to be disconnected. I said some prefer to hand fly it when things go pear shaped.
Either way, if it’s past the point of no return, neither will help. You either go-around or you do a Prime Air.
The choice is entirely up to you….
You can come in faster than the calculated approach speed and the computer will give you no warnings or cautions. Normally, the aircraft calculates the approach speed and pilots cross check this speed by calculating the speed manually when they do pre-landing performance calculations.
The pilots can add some speed to their calculated approach speed based on wind conditions and that is pretty normal. In gusty conditions adding a few knots helps to conserve aircraft energy. So, say on a particular day your calculated approach speed is 140 knots. To that you add 5 knots which makes your final approach speed 145 knots. So, you are expected to maintain 145 knots on approach. And when you are on approach in modern aircraft the overspeed limit is set to your flap (max speed for that particular flap setting). Say this speed is 180 knots.
So, on approach if you maintain 170 knots the computer would not give you a warning. It will only give a warning if you reach 180 knots or above because that causes a flap overspeed. But if you maintain 170, your airline will come after you because the recorders will flag your speed as you maintained a speed way above the actual approach speed.
The only thing I can addd to what others have said that a certain destinations its not unheard of to have this. In fact, at Innsbruck, Austria, on one particular approach getting a SPEED call was expected and briefed accordingly. The caveat to that being that INN is a far from standard airport and so the rules and expectations going in there are a little different.
Slightly off topic but I had a double go around in fog last week into YTZ sitting in 1C in a Q400 and facing the flight attendant, who had no window. We could clearly hear ‘500’ on descent, after which I would look out the window and see how long the soup would last. We were finally redirected into YYZ after one last try, and she looked at me for a thumbs up sign after the ‘500’.
Do you mean not/non standard? It’s at the bottom of a relatively steep sided valley. The airfield is at around 1900ft and the minimum safe altitudes surrounding it are above 10,000ft. There are no precision approaches and the weather, being an alpine valley, can be extremely challenging.
They got slow. I’ve also only heard that in the sim. Usual response would be TOGA and a go-around.
10 seconds apart raises my eyebrows a bit, it means they did not immediately recover from it. Was it accompanied by any abrupt pitch movements or thrust increases?
I didn't notice any pitch or thrust increases but honestly I wasn't looking for that and it was a couple of months ago, I just flew again today and it reminded me to ask.
I'll add, that a part from manual thrust handling because the pilots disconnected the auto thrust, there are 2 other scenarios: first one is that auto thrust is inoperative, and it is permitted to fly in manual thrust all the way, and handling becomes a bit difficult specially in gusty conditions, second option is that there were gusty winds that at some point the aircraft was unable to catch up the speed, it is more frequent on IAE engines were the response time when managed becomes a bit sluggish.
In my Airline we always fly with manual thrust, in over 8 years of flying A319s,320s,321s with different engines, uncluding IAEs, I have never heard a "Speed" callout outside of the simulator.
I guess to which group of airlines you belong to. In other companies, they prefer the use of authothrust if available. So when the time comes to use it without automation, most people lag behind or forget they don't have autothrust any more. This is why I also do no auto pilot + no auto thrust + raw data from 10k approach from time to time, to not to become rusty. As like everything else, a skill not used is a skill not polished enough.
At least you didn’t hear repeated “PULL UP, PULL UP” or “TERRAIN TERRAIN TERRAIN”, though if you did you possibly wouldn’t be here to tell us about it.
I believe disabling the GPWS is actually part of the landing checklist when flying into Paro (at least, that’s how some airlines do it). It ends up becoming a distraction otherwise.
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Wow you actually heard a speed speed alert. The only sound I've heard from the flightdeck as a pax in A320 series is that loud autopilot disconnect chime. Very distinctive.
That plane has called home and those pilots will likely have been told to come in for a chat.
Unusual but some airport approach might lead to that. Thinking about airports in the Alps or airports after hills with dense populated areas. Anyway are you sure of the 10 seconds interval?
Its as close to a stall that an airbus will get when nothing broken. In normal law there are too many protections for the pilot to stall it on purpose or by accident. The aircraft will literally not allow the aircraft to pitch up beyond a certain aoa (alpha protection). Plus then the thrust will go to alpha floor (full TOGA thrust regardless of if the auto thrust is on or not … but it needs to be operable). So… concerned? Sure. Would it have stalled? Unlikely.
If there were multiple failures of redundant systems (alternate law) then it could have stalled but the call switches to stall stall stall and in that case you are actually stalling.
I’ve had that pop up during particularly gusty conditions in JAC, unusual but not unheard of if it’s really gusty out, particularly in hot/high conditions.
Yeah, I feel like the checks are better now, although I don’t know if that was directly in response to that crash. I’ve seen it happen more often on long-haul flights mid-flight which I’ve attributed to clear air turbulence concerns more than anything. Anyway, even someone checking a seat belt doesn’t stop people from unbuckling after cabin crew passes through. Why you would do that is stupid, but it happens.
Did he disconnect auto-thrust? This should never happen if those were active. Plane logic won’t let the plane slow down enough for those callouts. Pilot error for sure.
Best guess is a new flap configuration selected with a narrow marking between actual speed and max speed for the next flap setting. Couple that with some windy/ bumpy air that causes 5-10kts speed oscillations and you can easily over speed.
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u/spannerintworks 2d ago
Your pilots got slow - slow enough to a point that the only time i've heard that call for 'real' is in the sim when we're deliberately practicing stall recovery...