Flying below VAPP - What to do ?

[Zenj]

on approach with auto thrust on , you find speed going below VAPP or even getting to VLS , what do you do to recover back to your VAPP ?

Thanks

[DJ77]

I would recommend you should start praying seriously (for once).

[Ollie Onion]

^^^^ What he said!

[safelife]

Another option, but thrust levers into FLX/MCT momentarily.

[PURPLE PITOT]

I have to assume you are talking about one of those death busses, otherwise you could simply mover the thrust levers to an appropriate position, you know, like a pilot:ugh:

[safelife]

I'm aware. But it was, for many years. As I wrote, another option.

[ACMS]

Momentarily advancing the thrust levers forward of the detent is perfectly fine.

Just make sure you are in a modified Aircraft otherwise below 100' AGL it will get interesting when you put them back :eek::eek::eek: All of ours are modded and if required I've been known to employ this method when I see IAS heading south and the A/T slow. Seems to work ok.

[C_Star]

@ACMS

What happens in non-modiefied a/c?

[ACMS]

A330 FCTM quote with regards to loss of speed:---

In gusty wind conditions, the A/THR response time may be insufficient to cope with an instantaneous loss of airspeed. A more rapid thrust response can be achieved by moving the thrust levers above the CL detent (but below MCT). The thrust will quickly increase towards the corresponding TLA. The A/THR remains armed and becomes active immediately the thrust levers are returned to the CL detent. Therefore, the thrust levers should be returned to CL detent as soon as there is a positive speed trend. However, there are two important points to note:



‐ Selecting the thrust levers to the TOGA detent, even momentarily, will engage the Go-Around mode,
and. ‐ In some aircraft selecting the thrust levers above the CL detent below 100 ft RA will disconnect the A/THR. In this case, returning the thrust levers to the CL detent will set climb thrust. Refer to FCOM DSC-22_30-90.

[C_Star]

Selecting the thrust levers to the TOGA detent, even momentarily, will engage the Go-Around mode,
and. ‐ In some aircraft selecting the thrust levers above the CL detent below 100 ft RA will disconnect the A/THR. In this case, returning the thrust levers to the CL detent will set climb thrust. Refer to FCOM DSC-22_30-90.

Oops, that might make things interesting...:E Not the loss of autothrust itself, but the unexpectedness of it... Is it an A330 specific thing, or do A320 have this as well?

[ACMS]

Yes it's caught out a few boys and girls in the past but not now as we all know about it. ( no I'm not one :ok:)

Don't know about the 320 but it's probably similar?

[Amadis of Gaul]

Another option, but thrust levers into FLX/MCT momentarily.

I was taught that option during OE. Only had to do it once in 18 months, though.

[safelife]

Does any operator actually do approaches with autothrust on the A330?
I know it's common on the A320 but on the Airbus 330 the speed tracking is dismal to say the least.

[ACMS]

Yes it's standard Airbus ops at our mob and we have the largest fleet of A330's in the world ( or at least we did )

I use it unless it's really gusty, then I'd rather do it myself, unlike the mighty 777.

[sierra_mike]

from FCTM/NO-Normal Operations/NO 110-Approach General/FINAL APPROACH

If the A/THR performance is unsatisfactory, the pilot should disconnect it and control the thrust manually.

[Intruder]

on approach with auto thrust on , you find speed going below VAPP or even getting to VLS , what do you do to recover back to your VAPP ?
If you have to ask, go back to flight school or find another career!

[RAT 5]

Reading this scares me a little. I am a Boeing pilot and know nothing first hand of the AB families. I also fly small piston a/c. In all my types of a/c over a long career thrust management has always been very simple. Forward = more and backward = less. As Pf you decide what datum to set and adjust around that. A/T might be used on later types, but needed watching and if it was slow to respond then my hand was always rolling through and told the silly billy what to do. never a word of thanks. Watching cadets in TR plug in the automatics and them not monitor them is most amusing, especially if they haven't noticed A/T has gone not ARM. The speed goes off the end or decays in to stick shaker: and I let it. They seem so bewildered that "the computer was engaged and it didn't do its job." A salient lesson learnt and never forgotten.
Back to my point; thrust/speed management was easy and intuitive. Now I read about the AB types that do this or that if you select this detent or that, and if you do this above 100' the a/c will assume this and if you do it below 100' it will assume something else and thus cause a whole chain of events to try and catch you out. Am I being staid in my ways or are they making an easy job difficult? If I first have to think about what else will happen if I push the thrust levers forward or backwards and by how much then it might cause unwanted hesitation, especially if operating different modified thrust systems e.g. A320 & A330 as has been mentioned here. Ouch.

[JulietSierra6]

Clearly this is an Airbus specific topic but I have to agree with a few of the other guys. This discussion shocks me to say the least. All my limited experience is of Boeing but come on, can you hear yourselves?

I don't know whether to laugh of cry.

[Case One]

Originally posted by ACMS:
Don't know about the 320 but it's probably similar?

It certainly was when I flew them, but that was over a decade ago. Landing in moderate/ severe turbulence could be interesting. With your entire body bouncing around, your hand on the thrust levers could easily knock them slightly out of the gate. The chime and ECAM caution weren't particularly attention getting in that situation, and an already entertaining approach could see a surprising flare.

Nice to see those with no AB experience chiming in as usual. Boeing's moving thrust levers are great, and speed tracking does seem better than on the 330/340. However, on AB's non-de-rated types; just pushing fully foward for TOGA thrust and guidance beats Boeing's TOGA button logic/ finger faffing hands down. Not to mention the dubious wisdom of HOLD mode, or having to frequently over-ride the autothrottles on an RNAV STAR in VNAV. A bit like flying with an obstinately poor student. Neither system is perfect and both present opportunities for embarrassment, especially when converting between them.

[hikoushi]

on approach with auto thrust on , you find speed going below VAPP or even getting to VLS , what do you do to recover back to your VAPP ?

Thanks

Step by step:

1. Disconnect all automation.

2. Add power.

3. Put the nose down a little.

4. When speed trend recovers and you start to feel a little "whooop" lift in the seat of your pants, reverse the motion and recover flight path.

5. Land.

If that all seems improbable at the time choose option B.

1. TOGA / GTFOOD (Get The F Out Of Dodge).


Also, the Airbus G/S Mini mode WILL allow speed to decay below Vapp momentarily in very gusty situations. It won't allow it to decay below Vls if all works as advertised. Regularly land in very gusty wind and it does in fact work quite well (A330). Like others have said I do like the feel of manual thrust in those conditions. Hold a stable power setting and let the speed vary a little. Which, come to think of it, is basically what the G/S Mini function is trying to accomplish anyway by giving you a variable speed target.

If the automation doesn't do the job, turn it off. If you work for a company that absolutely forbids this, or you are simply not comfortable doing so, then your choice is simple, go land somewhere else. Bottom line.

[sonicbum]

on approach with auto thrust on , you find speed going below VAPP or even getting to VLS , what do you do to recover back to your VAPP ?

Thanks

Wait... what's the problem with the speed going to Vls ? Give it a second or two and you will be back to Vapp.

[vilas]

"on approach with auto thrust on , you find speed going below VAPP or even getting to VLS , what do you do to recover back to your VAPP"
There can be two situations causing this to happen. One is ATHR unable to respond to rapidly changing situation. In that case manual thrust is an option. The second is if the down drafts are beyond the capability of CLB thrust value itself, in that case the thrust will be already at CLB and flying in manual thrust or select speed is not going to help and you cannot increase thrust without going past CLB gate which is not recommended anymore. If you are on GS you may push the nose down to go down to permitted deviation value to see if the conditions improve but if already low and slow pushing nose down is not an option. If you are nearing 1000ft. AGL only option is to GA and attempt another landing in lesser configuration like Flap3.

[macdo]

I used to like the nudging the TL's out of CL to cure the problem, but banned in our outfit now.
Always check that you have a good 5kt between VLs and the bugged Vapp after landing flap selected. Adjust Vapp in the MCDU if not. Even 2kts makes a significant difference to the lazy Airbus ATHR.
If it really gets out of hand take the automatics out.

[ACMS]

I much prefer the Boeing A/T setup over the Bus any day of the week.....

Having said that the Bus system works ok, takes a little getting used to after the simple Boeing but it works ok.

The thrust bump technique is indeed still in the latest updated A330 FCTM we have and it's approved by Airbus.....( as I posted way back )

[sonicbum]

We have this SOP in our outfit too. It's not an Airbus technique. According to Airbus, the VLs computed by the FMGC and displayed on the PERF page is more accurate than the VLs displayed on the PFD computed by the FAC. The FMGC computes Vapp as VLs+5kts so Airbus philosophy is to leave it alone under normal conditions (not gusty crosswind etc.). I think this five knot gap thing is an airline response to perceived tail strike risk.

On latest MSNs you have consistent informations between the PFD and MCDU as the FAC computes operating speeds based on the FMS gross weight.

[Microburst2002]

Lots of Top Gun pilots here!

But it is a good question, because there is more to it than it meets the eye.

First, you can make hundreds of landings and the sluggish A-330 A/THR will lag many times, without going below VLS, but well below VAPP. Below VLS is indeed a rare event (seen it twice in 4 years)

Second: GS MINI is fantastic, except if you are in the A-330 with its sluggish A/THR. When you see you are 6 kt below VAPP and increasing and thrust doesn't move a freaking decimal of N1% even after several seconds, you have at least the right to name it sluggish.

Third: If you are flying the A-330 on behalf of an airline full of OM stabilized approach restrictions and FOQA, this scenario is way different than if you are in a more relaxed, pilot friendly or pirate airline. In the former, you can be sacked or demoted for an unstable approach, so if you have this situation at 500 or below, you should go around. Or shouldn't you? How many knots below VLS should trigger the go around decision? Depending on the trend? What is my ops department opinion regarding that matter?

There are deviation call outs. The question is What do you do when the PM says "speed" and A/THR is engaged?

a) disconnect the A/THR and carry on manually
b) do the thrust levers momentarily above CLB detent technique
c) say "correcting" and hope that the A/THR decides to correct and start increasing N1, at least enough for the trend to be on the recovery side, we will be good soon before flare, lets see...
d) go around because you are not stabilized anymore.

You might very well decide a), b) or c) and then be sacked. Even Maverick could be sacked for that (and Gus sent to CRM rehab. "I got your tail, man").
You might choose d) and then be questioned about an unnecessary go around "come on, man, it was 2 knots and already with positive trend, be a man". Some good airlines will not question a go around, but others will.

So the question that the original poster made is a very good one, indeed.

[Uplinker]

My previous fleet manager told me that Airbus A/THR maintains bug plus or minus 5kts, whereas we pilots prefer to see a range of bug to bug +10kts. In other words, we are uncomfortable seeing speed less than bug, but the aircraft design has taken this into account and it is OK.

In addition, on approach the Airbus minimum groundspeed system keeps the groundspeed constant - which is more relevant for landing - rather than the airspeed, and although mini G/S is very good and safe system, its variations are perhaps not totally intuitive to pilots who are programmed to keep airspeed controlled.

Having said that, the 330 did sometimes give me cause for concern, and I really liked the "phase advance" technique of pushing the thrust levers forward of the CLB detent and back to "wake up" the A/THR.

Problem with that was, some pilots would push the levers forwards and leave them there for several seconds, by which time the engines would be producing far too much power and destablise the ship. All that was required in phase advance was click out click back, in the same time it takes to say that out loud. But as usual it was never explained properly and some folk got it wrong, so they banned the whole thing. Shame.

[Microburst2002]

Airbus minimum groundspeed system keeps the groundspeed constant - which is more relevant for landing - rather than the airspeed
I disagree. Airspeed is always relevant and primary. GS mini just adapts the speed target to maintain that computed minimum GS that will protect you from a possible gust. So when the gust hits you, the extra knots given to your target speed by GS MINI to the are 'spent', their role has been fulfilled and the target decreases to the new value after the gust. Nice!

However it will not suffice if the gust is worse than anticipated (some think that GS MINI will protect you from any gust no matter the intensity) specially if the A/THR is sluggish.

[ACMS]

UPLINKER:----ok I'll challenge you statement that it was banned, by who? Certainly not Airbus.

This is the latest A330 FCTM that our company must get approved by Airbus............

It CLEARLY advocates the use of this technique.

In gusty wind conditions, the A/THR response time may be insufficient to cope with an instantaneous loss of airspeed. A more rapid thrust response can be achieved by moving the thrust levers above the CL detent (but below MCT). The thrust will quickly increase towards the corresponding TLA. The A/THR remains armed and becomes active immediately the thrust levers are returned to the CL detent. Therefore, the thrust levers should be returned to CL detent as soon as there is a positive speed trend. However, there are two important points to note:

‐ Selecting the thrust levers to the TOGA detent, even momentarily, will engage the Go-Around mode,

and. ‐ In some aircraft selecting the thrust levers above the CL detent below 100 ft RA will disconnect the A/THR. In this case, returning the thrust levers to the CL detent will set climb thrust. Refer to FCOM DSC-22_30-90.

[sonicbum]

Third: If you are flying the A-330 on behalf of an airline full of OM stabilized approach restrictions and FOQA, this scenario is way different than if you are in a more relaxed, pilot friendly or pirate airline. In the former, you can be sacked or demoted for an unstable approach, so if you have this situation at 500 or below, you should go around. Or shouldn't you? How many knots below VLS should trigger the go around decision? Depending on the trend? What is my ops department opinion regarding that matter?

There are deviation call outs. The question is What do you do when the PM says "speed" and A/THR is engaged?

a) disconnect the A/THR and carry on manually
b) do the thrust levers momentarily above CLB detent technique
c) say "correcting" and hope that the A/THR decides to correct and start increasing N1, at least enough for the trend to be on the recovery side, we will be good soon before flare, lets see...
d) go around because you are not stabilized anymore.

You might very well decide a), b) or c) and then be sacked. Even Maverick could be sacked for that (and Gus sent to CRM rehab. "I got your tail, man").
You might choose d) and then be questioned about an unnecessary go around "come on, man, it was 2 knots and already with positive trend, be a man". Some good airlines will not question a go around, but others will.

So the question that the original poster made is a very good one, indeed.

Hi MB,

I believe that even in your airline if stabilized criteria are met during the approach and subsequently there are minor deviations due to environmental conditions then it is accepted. If you believe, according to your airmanship, that it is not "minor" anymore, than go around. You can be questioned for a go around for sure, but not more than questioned unless something happens during the go around of course.

[Microburst2002]

That is what I don't like. I don't want to have to decide how long is too long, and how many knots are too many, or how much is "minor".

It remains a mystery why the A/THR is so bad in approach in the A-330. It is very frustrating when it freezes no matter what.

[Uplinker]

Hi ACMS, I meant that my company banned the procedure, but the impression I got was that it came from Airbus. I am delighted that it is not banned by Airbus (with caveats), and will therefore keep it in my back pocket for those hot, thermally approaches which sometimes confuse the A330.
Cheers !

Hi Micro, yes, perhaps my meaning was not very clear. GS mini is an airspeed target which is computed according to the tower wind and any detected wind changes on approach, and is followed by the A/THR to keep the groundspeed above a certain minimum, based on the groundspeed required at touchdown. When the headwind increases above the tower headwind the GS mini increases its target, increasing indicated airspeed to maintain the groundspeed.

In my experience it does a very good job but obviously, really big gusts can upset this, as they can upset anything.

I wonder if Airbus forgot to program the "Approach autothrust" mode into the A330? (This mode makes the autothrust more responsive to speed variation below 3200' rad alt.)

[sonicbum]

MB if you fly an approach in gusty wind conditions speed excursions are just going to happen, there is nothing you can do about it, regardless of the A/THR being ON or OFF.

[Microburst2002]

I know what GS mini is and how it works. The problem here is that the A/THR fails to keep the speed target, for no known reason (N1 steady, no reaction).

[Microburst2002]

sonic

In some cases the gusts are slow and there is plenty of time to counter them, only the A/THR is just frozen. In manual thrust it would be easy. I wonder what is the reason.

[Microburst2002]

:uhoh:

As it appears, in the A-330 IAS TARGET computation differs when below 400 AGL.

[Zenj]

I'm very much disappointed by post from John_Smith !

He calls me someone not a pilot and doing things in the MSFS , well just for your information I have been flying for 30 years and mainly on the Boeing and its just these last 2 years that I have gone to the Airbus and just ask anyone flying the Boeing, A/T is not an issue as long as you can follow it with other parameters and almost all Boeing pilots are good at flying manually with A/T Disconnected.

Have you read the recently released AAIB report of the British Airways A319 that lost cowlings in the air and eventually leading to engine fire ?

The commander had not flown with manual thrust for the past 7 years before accident and F/O had never flown completely in the aircraft.

FYI i have the knowledge mentioned but I have seen speeds going below VAPP and close to VLS on one of the aircrafts and this is the reason I asked because I'm told Airbus did have a procedure before but now it has been removed on A320's.

The bottomline is , we are here in this particular forum to learn and there is no pilot who is perfect , we have seen the best pilots doing the most silly things that turned into disasters.

So Mr. John Smith, please do not accuse or tarnish people here by just asking questions , if you find them silly please just hit the back button and do something else, the 3,098 views and almost 40 posts were not useless people but these are pilots trying to support and some trying to learn !

Thanks always for those who take their time to explain things !

[RAT 5]

I do not know about other FBW a/c, including military. Are AB the only manufacturer who has designed static thrust levers? If so, they have also designed these, what seem to be, confusing 'gates' of thrust. Why try to reinvent the wheel? Forward = more umph and backward = less. The pilots decides. If he wants G/A he activates a G/A button and shoves the levers away from him. If he wants to land and slow down he pulls them towards him.
I'm an old soul and it all sounds so simple. All these thrust gates, and activating G/A mode by surprise and landing mode by surprise seems too much of a surprise for me. I think flying should be intuitive. This seems complicated. There will be those who say; "ah, but when you get used to it it is OK". Now we all know some are sharper than others. Some may never get used to it. They've been told to let George do his thing and you'll be alright. It can't fail. Well we've all seen were that has led to. I'm trying to fathom the benefit of having static thrust levers in A/T mode and all these various automatic mode activated gates. If ever there was a cause for "what the f@£k is it doing now?" then surely this is it.
I stand to be corrected and learn from my peers. I'm an old dog seeking new tricks, but only if they ware worth effort.

[truckflyer]

A319 have this problems all the time, and I have seen some A320's also with this issue.

Following unofficial procedures seem to resolve this issue 90% of the time.

1. Reset the ATHR on the FCU, simple OFF / ON
2. Increase the Vapp 2 - 3 kts if seen creeping down towards Vls
3. If neither work, pull selected speed, consider going for managed Speed during final few hundred feet of the approach.

4. If all these above fails, go manual thrust, normally the ATHR reset on the FCU works

[vilas]

Zenj
Use of ATHR requires 5kts. addition to VLS. Why is that? Obviously it is because the system will let speed go 5kts. less sometime. It is not an issue. It doesn't happen in normal circumstances but when atmospheric conditions are demanding. For stronger winds there is addition from 5kts to 15kts at pilot's discretion. I do share John Smith's confidence in A320 ATHR and GS MINI.
truckflayer's suggestions: First, Non standard method of reengaging ATHR seems harmless enough but I do not know if it really works. Second and third not a good one because it negates GS MINI. Fourth one going manual thrust should be done before 1000ft according to Airbus.
RAT5 There is nothing intuitive for humans in the air. The correct word is habitual from earlier aircraft. Habits can be unlearned or learned. I am sure Airbus designers knew all those points you mention. There is no point fathoming airbus while flying a Boeing non FBW. If you were to fly an airbus for a living you will do it as efficiently as anything else you flew. As the US airways pilot Eric Parks on his airbusdriver.net says "Welcome to Airbus! all resistance is futile,you will be assimilated, "

[7478ti]

After having flown, tested, or evaluated all four big jet manufacturer's types in some of the most stressful conditions or configurations experienced within the flight envelope, and some times in ranges beyond the edges, ...for nearly four decades, ... these three pages of comments alone, addressing this simple question, ...provide a "telling story" regarding the suitability and characteristics of the modern Bus non-moving throttle design. In that regard, these three pages of comments alone are all that's needed, to begin to draw conclusions about the real story, of both the suitability, strengths, and weakness of that particular pilot-aircraft thrust/speed interface. It should be as simple as either AT ON, or alternately push forward for more thrust, and pull back for less, as needed, ...if the AT isn't doing what you expect or need. Even the issue of electing to disconnect the AT, or not, is secondary.

[vilas]

This Airbus thread is squawking 7500.

[Denti]

I have to say in some way i do agree with 7478ti. After switching to the airbus i sometimes missed the in-between way of dealing with slow or non-behaving autothrust on boeings. If it is to fast pull it back a bit and then let it continue on its own, or push it forward somewhat and then let it continue on its own.

On the bus i have to disconnect it completely, after i have to sync the thrust levers to the current thrust level first. It is somewhat more cumbersome. Interestingly enough 99% of us do fly (nearly) always in manual thrust when in manual flight as a result of that. In fact, some have to do the odd autothrust on approach to keep current in this kind of operation. It is just much easier to fly manually in manual thrust, but that is of course my personal opinion. Even manual thrust in automatic flight sometimes works better than both in automatic.

[Amadis of Gaul]

Zenj,

Regardless of whether you're legit or not, I don't think this is a place to learn much of anything anymore (I'm not sure it ever was). This is cheap entertainment, sometimes even pretty good entertainment.

[Microburst2002]

The german philosophy (in LH and others) is to disconnect the A/THR every time disconnect the AP. No matter what Airbus says. I kind of like that.

On the bus i have to disconnect it completely, after i have to sync the thrust levers to the current thrust level first. It is somewhat more cumbersome.


one going manual thrust should be done before 1000ft according to Airbus.


The problem here is that we don't have freaking options when we face that situation!

The A/THR is not doing the job? Disconnect… No, wait! It is too late to disconnect already, So… What the f*** do we do??

Answer: Go around.
That is what it all comes to: go f****n around. No other options. So in this regard, it is clear that the autothrolle system of Boeing is superior. It gives more control. I have to admit it.

[truckflyer]

On the 319 it is nearly a "standard procedure" to add 2 -3 kts extra on the Vapp, as it does not hold it's speed. Does not matter even if in fairly calm conditions! It will even fluctuate/flicker below Vls if nothing is done. I personally prefer NOT to sit and wait and see what might happen or how low it might go, as I am not paid to be an Airbus test pilot!

The ATHR disconnect in the FCU does work, it goes momentarily into THR LOCK until engaged again.

I never saw this problem on the A320 with IAE engines, but I did see it also on the A320 "sharklets" with CFM engines.

No idea if any connection between this, just my observation.

[Gary Lager]

I don't see why so many people get het up about non-moving thrust levers. If A/THR engaged, you don't move them, if in manual THR, you do move them. This the same principle in both both Boeings and Airbuses.
Bottom line: Monitor A/T response; if this doesn't work, use manual thrust.

The two or three most significant & well-known accidents/incidents I can think of where crew failed to monitor approach speed, and assumed the A/THR was working when it wasn't, were all Boeings. So what does that say about the benefits on moving thrust levers? (Asiana @ SFO (https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCEQFjAAahUKEwjR96yp6qPHAhWMcBoKHRcdAI8&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FAsiana_Airlines_ Flight_214&ei=VGLLVdH9M4zhaZe6gPgI&usg=AFQjCNHQSH9j5KJhwsjcaBnHbiniB6NHCA&bvm=bv.99804247,d.d2s), Turkish at AMS (https://en.wikipedia.org/wiki/Turkish_Airlines_Flight_1951), Thomson at BOH, 2009 (https://www.gov.uk/aaib-reports/aar-3-2009-boeing-737-3q8-g-thof-23-september-2007))

[Uplinker]

Agree with GL. Airbus FBW A/THR does encourage a proper instrument scan.

[7478ti]

Ref GL and (Asiana @ SFO, Turkish at AMS, Thomson at BOH, 2009)

True... any airplane can be improved, even the T7 ...and any FCOM or FCTM or pilot qualification program can better cover more of those 1x10E-4 or less probable situations that we often see "once a week", ...it's just that some airplanes can benefit much more from improvement due to chronic weaknesses than others.

It would take many more than three pages here, and citing a mere three examples, to comprehensively address this "non-Moving throttle" and AP/AT disconnect subject. An entire FAA report was dedicated to subjects like this (back in 1996), and it still stands. In fact, hardly anything has changed on this non-moving throttle issue since those very first discussions with advocates like Gordon Corps, PB, and B Zed, ...on the troubling HF aspects of this subject, that began at least in the early 80s. I still vividly remember those meetings, and the predictions of the inevitability of this entire discussion.

Jun 18, 1996 - Federal Aviation Administration. "The Interfaces Between Flightcrews and Modern Flight Deck Systems".

[RAT 5]

Guys: there have been various opinions voiced here about the ATHR systems and some of their idiosyncrasies. Some have outlined their weaknesses and slightly inconvenient characteristics. I've expressed my thoughts on complicated non-moving ATHR systems. An attempt to reinvent the wheel. But, a further observation; guys have suggested 'work arounds', 'tips & tricks' to bypass the basic design and overcome the unwelcome quirks. If that is the case then surely it says that the original design is not correct and should be re-done? It's not healthy to have a weak system design and allow random crews to devise their own working solutions, while others follow the manufacturer's ideas and fall into the lurking traps.

[Goldenrivett]

Hi RAT 5,
If that is the case then surely it says that the original design is not correct and should be re-done?
British Airways Airbus A320 Pilots' Autothrust Survey (http://papers.sae.org/912225/)
"BA concludes that from a Flight Operations perspective a future system should consider providing movement between the idle and climb power positions, whilst retaining the A320 thrust setting and engagement “detents” technique."
Steve Last & Martin Alder.

We've been waiting since 1991 - so don't hold your breath!

[7478ti]

That BA based pilot suggestion might very well work better (i.e., less bad), particularly if the FHA, FMEA, and SSA was carefully done, and the conclusions supported that change... good comments by both RAT 5 and Goldenrivett!

But I also concur... "Don't hold your breath!". I've been dealing with Busses and waiting for that change of heart, and philosophy, since at least the first A300B2K in the US back in the 70s, ...and then later waiting, since at least those 1982 conceptual discussions, for a better thrust solution, and sidestick interconnection solution, and soft limit solution, ...since well before the first AutoBus even flew !

[Also see the other pPrune parallel thread, about recent A320 speed mgt issues]

[RAT 5]

I wonder if the faults/short-comings being exposed can be traced back to the operational design philosophy. A B732, even 733/4/5 were designed to be sturdy workhorses and could fly into some inhospitable tiny places and also the large cosy nests of major hubs. They, later models, even had LNAV/VNAV and could autoland. I wonder if the AB's FBW started life with a clean sheet of paper and were envisaged to be flown into major hubs with autopilot + auto throttle down an ILS to minima and then the human intervened; or autoland. It was designed to be an automatic pilot monitored a/c from immediately after takeoff to immediately before landing. It was route tested as such. OK, it had to jump through the various certification processes for VMCA/G stalls etc. but largely it was operated via automatics.
Then it was sold outside its design nest and replaced many of the older simple Boeings on routes outside major hubs. Adventures arrivals into nasty weather/winds Greek islands: tiny mountainous terrain infested airfields, all of which involved human intervention long before "immediately before landing". Mk.1 eyeball arrivals with hand on stick. Scare Blu!
Those with much more experience of AB's, and perhaps those with experience on both AB & Boeing, will inform us which is the easier/better to land in nasty gusty X-winds. Speaking to easyjet friends who flew both, it was common to want AB on smooth days and Boeing on nasty ones. What is the consensus? They should both be able to do both adequately. But having seen some videos of PIO on short finals the side stick brigade seem to have it much harder to keep the bucking bronco under control and not be spat out of the saddle.
There was a significant difference in B737 family & B767 on nasty days. The control column was much calmer in the larger a/c. B733 was stirring the pot; B767 more gentle inputs. How is it from A319 - A330/340/even 380. I suspect the large super whale might treat mother nature with some disdain, or is it still a handful? It will be interesting to hear, after many years of line experience, just how the revolution has succeeded, or not. In the early days of AB FBW, on Prune, there was an ongoing debate of the B757 v A320. There were definitely 2 camps. How now?

[Chesty Morgan]

I feel sorry for you lot having never flown the E195 which has the best AT system ever.
:p

[Uplinker]

Hey RAT, that is interesting, there might be a lot of truth in what you suggest, I don't know.

For what it's worth, my two penn'orth is that in my experience, Airbus is very poorly taught. They are so keen to get us into the air and learn how to do ECAM, that basic handling stuff is really glossed over, and in my case was not properly taught at all. All that was said about the side stick were really stupid things such as "pretend it's a docker's dick and don't touch it unless you have to", or "only hold it at the top" or "only hold it at the base", and other such useless comments which did nothing to actually explain how to use it. We have never been taught or shown how to do turbulent approaches in the SIM or for real. PIO's on FBW Airbus are therefore mostly a result of poor training in my view. I eventually taught myself how to use the side stick correctly - after watching a video of a Tornado pilot. Years later I explained how to use the side stick to a TRE who had trained me !

The one thing you cannot do in an FBW Airbus is 'follow through' on the controls - i.e feel what inputs the trainer is making - since the sidesticks are not mechanically linked. This is a shame because that is a valuable way to learn to handle a plane.

I have not flown Boeing apart from in the SIM, and my previous types were non auto thrust. However, from a handling point of view I did fly the BAe146, and many was the time I could feel myself overiding the servo tab controls and hitting the mechanical stops on the control surfaces when I needed to reverse control direction as I flew a turbulent approach. I have never needed to do this on an Airbus - well of course it's hydraulic not servo tabs - and you just centre the stick when your input starts having an effect. So I probably find the Airbus easier than the dear old 146. The Airbus side stick needs a different method and the knowledge that the FBW is helping you and doing some of the work for you.

I have flown A320/321/330, and their response is similar thanks to FBW, but the 330 is obviously much larger, has more inertia and is less upset by the atmosphere, like any large aircraft.

The idea of a hybrid system of having moving thrust levers from Idle to CLB and then detents for MCT and TOGA is interesting. Of course we must bear in mind that even moving thrust levers are the input, not the output of the system - which can only be seen on the N1/EPR gauges, so a scan of the engine instruments is still required. You can select the engine instruments onto your ND in the A330 which makes the scan easier on short thermally finals if the A/THR is being lazy', though it is not SOP.

[7478ti]

RAT. Excellent comment.

I cannot speak to the 380 at all (no experience with it)... , but after at least three decades of dealing with both, for all the other AutoBusses and their comparable Seattle products through the superwhale and plastic jet, there are very real differences in both philosophy, as well as control system design (as well as FMS/FMF). These lead to meaningful differences in performance in difficult WX conditions reference limits, margins, phase margin, gain margin, and vulnerability to PIO/APC. With firsthand experience in the most difficult of conditions, there were days where I'd be quite comfortable operating with one, and wouldn't even consider anything but parking it, or a diversion if airborne, with the other.

As to the subsequent E195 AT comment by CM... note that an AT alone, ...without an also excellent RNP, GLS, and a capable FMS/FMF is pretty useless. No E195 can yet even come close to touching a Cat III LAND3 while handling an unexpected a 40kt gusting XW, with an engine shutdown, or RNP .1 into or out of PAJN, NZQN, CYLW, or ZULS with a first E/O, or lightning strike electrical bus shed... and never will, at least not with their current Piper Apache 1950s vintage systems and flight control architecture, and primitive FMS.

[vilas]

Simple fact is Airbus FBW is a different philosophy. It is completely different from the trainer aircrafts a pilot learns his craft on. It is not only thrust but vector stable behaviour also is different than what you get to learn during your transition to commercial pilot. It all started in 1988 and the order book of airbus in 2015 is pretty impressive. That shows this philosophy is here to stay and is successful. It may not be technically and commercially possible to mix and match different concepts and commercial success obviates any need for that. Humans will always like and dislike things. It is a good topic for discussion but non airbus pilots or who detest it's concept should not hijack every topic airbus pilots are discussing towards their favourite past time of airbus bashing. Because it defeats the purpose of the original post. Start a new thread by all means. Also the opponents add nothing new and keep chewing the same bones.

[7478ti]

With all due respect sir, pilots still routinely need to move between types, and they deserve to know the truth about what they're seeing, and why. That knowledge void, and those kinds of HF interface differences, was a main cause of the A300 accident at Nagoya decades ago, and that directly led to the 1996 FAA/Industry HF team Report (see below).

On 26 April 1994, the Airbus A300B4-622R was completing a routine flight and approach, when, just before landing at Nagoya Airport, the First Officer inadvertently pressed the Takeoff/Go-around button (also known as a TO/GA) which raises the throttle position to the same as take offs and go-arounds.

"The Interfaces Between Flightcrews and Modern Flight Deck Systems"
June 18, 1996

[Chesty Morgan]

As to the subsequent E195 AT comment by CM... note that an AT alone, ...without an also excellent RNP, GLS, and a capable FMS/FMF is pretty useless. No E195 can yet even come close to touching a Cat III LAND3 while handling an unexpected a 40kt gusting XW, with an engine shutdown, or RNP .1 into or out of PAJN, NZQN, CYLW, or ZULS with a first E/O, or lightning strike electrical bus shed... and never will, at least not with their current Piper Apache 1950s vintage systems and flight control architecture, and primitive FMS.

Well I'm pretty sure the discussion was about AT behaviour. The Embraer still beats the others hands down at that but it must be useless because it can't CAT III auto land OEI in a 40kt crosswind (what can?).

I'm also reasonably certain that when I was doing GNSS only approaches on it the RNP/ANP was probably quite small.

[itsnotthatbloodyhard]

There was a significant difference in B737 family & B767 on nasty days. The control column was much calmer in the larger a/c. B733 was stirring the pot; B767 more gentle inputs. How is it from A319 - A330/340/even 380

The 767 has excellent control authority (notably in roll), and rarely needs coarse inputs to keep it on the straight and narrow. For me, the problem with the A330/340 (can't comment on the other Buses) is the amount of lag in the flight control system. You simply don't have the sense of a direct and immediate connection with the controls. Again, this is most obvious in roll. When everything's smooth there's no problem, but it makes things a bit busy and unpleasant in the rough stuff. I can live with the non-moving thrust levers, but the autothrust system is slow to react and then applies excessively large inputs. This means it does things for which a human pilot would deserve a smack over the knuckles with a ruler (e.g. idle thrust at 150' due to a few excess knots).

[RAT 5]

With all due respect sir, pilots still routinely need to move between types, and they deserve to know the truth about what they're seeing, and why

There was a friend who flew with Air Belgium many tears ago. There he flew a mix of B734 & A320 in the same week. That sounds a handful. Is it possible today under EASA? It seems fraught with 'an incident waitting to happen.'

[7478ti]

CM, the answer to your question is that many can, and it has been demonstrated many times. The big jets are typically tested well beyond the values shown in the AFM or FCOM to be sure they are robust, and that they exhibit no adverse behavior in the event that conditions are unexpectedly or unknowingly somewhat worse than the values published for routine use. In fact if you look closely at these AFMs and FCOMs for some types, you will note that the autoflight limitations posted clearly additionally state the qualifier "when landing minimums are based on their use". So that in many instances, where reported visibilities are reported as above Cat III minima, but actual conditions are nonetheless equivalent to Cat III, such as in a driving rainstorm, or blowing snow, or even with a landing landing into a blinding sunset with bright reflections off the runway, these AL systems are beneficially and effectively used as an aid, sometimes in wind and gust conditions even beyond the value cited above.

As to the relative performance of the AT in the latest modern big jets, have you even used those systems in stressful conditions, to be able to make a relative comparison of their performance???

Regarding your comment about RNP and ANP, you noted capability during GNSS "SA OFF" operation, during normal ops, as for a GNSS approach. But this is hardly any indication at all of the suitability of your aircraft for RNP capability, which deals with containment in normal, rare normal, and non-normal ops. So even if the equivalent of ANP or EPE for your jet on a GNSS straight in approach was reasonable, that in no way addresses or assures its LNAV and VNAV ability to deal with RNP containment or useful RNP capability, especially at the lower RNP values down to RNP .1. It also says nothing of the overall AFDS and related system's ability to safely fly the necessary paths for departure, for RNP based RF Legs during approach, or for RNP paths on an E/O MAP approach initiated from the TDZ. To do so, the FMS/FMS and related systems like the redundant IRUs, standby electrical system, AP and FD, and map displays, in combination need to be demonstrated to be capable to achieve the specified robust normal, rare-normal, as well as non-normal performance, in designated conditions, including having adequate FTE for all the designated control modes to be used. In short, to date, there is no evidence so far that the jet you mention has or can demonstrate any of this, even for RNP procedures that have now been in beneficial and safe use globally now, dating back to before 1994. Perhaps you could jumpseat on a flight someday in a real RNP capable aircraft, into NZQN, PAJN, or CYLW or equivalent, and see this RNP capability used first hand, to better see how much more significant capability other jets now have, and why AT performance alone is only a limited part of an overall aircraft's operational capability, regardless of how good the AT might be? Which is just one more reason why this Vapp thread is quite important and significant, to those who are legitimately trying to understand and deal with these important questions and issues.

[Chesty Morgan]

:zzz:

What a lot of waffle. The answer to your question is yes, currently and in the past.

I'm interested in your definition of "real RNP capable". It seems like an odd statement seeing as the Embraer has a better ANP performance than the NG I currently fly. Have you ever operated the Embraer to allow you to make your comparisons? :rolleyes:

[7478ti]

Sir, ANP level alone matters little, as long as it's less than the needed RNP with adequate FTE margin (e.g., the reason for having features like NPS), and is predicted to stay less than RNP for any relevant non-normal conditions. Instead, it is the low RNP capability that really matters for an aircraft, and having it able to support RNP based LNAV and VNAV suitably, for any leg type combination needed, including for RF legs down low, while fully satisfying all the rare-normal, and non normal conditions that must be addressed in the FHA and FMEA. Yes, I am intimately familiar with that particular autoflight system, including even for the pending E2 design, and have seen no evidence whatsoever that so far it is capable, or will be capable of safely flying the real RNP procedures that I cited earlier, even for normal operations, let alone for rare-normal, or non-normal operations down to the TDZ and back out, even in the event of a first E/O, and first Nav failure, or any relevant system failure, such as a lightening strike bus trip back to stby power, while maintaining RNP capability (per relevant criteria such as in AC120-29A, which was the basis for RNP approvals for aircraft and airlines now doing [real] RNP).

[Chesty Morgan]

The point about ANP is that the ANP of the Embraer is accurate enough to carry out GNSS only, RNAV and VNAV/LNAV approaches and it has done so for years which, obviously, means it meets the relevant RNP. You're unaware of this?

I am intimately familiar with that particular autoflight system
Wizard, but that was not the question.

Still, the AT system is more intuitive and better in an operating environment than both the two types mentioned above.

[7478ti]

CM,... Not so. The fact that a system may have an ANP adequate to fly a "GNSS only" approach means absolutely NOTHING in an RNP world. ANP must always be less than, and be predicted to stay less than, the specified level of RNP (even for non-normals) for the specific RNP based procedure to be flown, with adequate FTE margin. Further, your assertion about "RNAV approaches with LNAV and VNAV minima" has nothing whatsoever to do with RNP based RNAV procedures (e.g., NZQN RNAV(RNP) RWY23). This discussion relates purely to those kinds of RNP based procedures, and is a subject for which no current BizAv based avionic system, as typically used in any RJ presently flying, comes anywhere close to meeting RNP.1 capability, for the leg types and configurations of the RNP based approaches noted, or duplicating the key capability needed to address rare normal and non-normal conditions for those procedures, as I cited earlier. I'm not aware of ANY RJ currently capably of flying RNP based procedures at low RNP values near or at RNP .1, such as needed at NZQN or PAJN, let alone for meeting the VEB related to the vertical RNPs associated with those procedures. In fact from what I've seen in recent months for design specifications for AFDS and FMS system improvements in the RJ fleets, and for even a few new designs in development in that class, this full equivalent RNP capability that has been flying in the big jets for years isn't likely to happen at any time soon in the RJ fleet, in even the intermediate future. Further, even the basic fundamental avionics architecture is weak in some of these RJ designs, potentially even permanently precluding beneficially combining use of modes for LAND 3 using GLS, also with low RNP capability.

[ACMS]

Would the last person please turn out the lights when they leave.

[Chesty Morgan]

I think what you're saying is that because the Embraer is not approved, but is capable, of RNP 0.1 then the AT system is useless.

Right.

[7478ti]

Sir, ...You say your RJ is "Capable of RNP .1". But Which RNP .1??? Straight-in??? It isn't adequate to just have some measure of accuracy under normal conditions, to fly some limited brief LNAV "straight-in" segment and claim RNP.1 capability. Instead, you need to be able to fly ALL the LEG TYPE combinations needed at RNP .1 (which there is NO evidence yet that any RJ can meet), ...meeting both the lateral and vertical RNP requirement based constraints, including for speeds, and later RTAs.

Further, this discussion isn't esoteric.

In fact, it is a core issue and key to any successful and economic and capable future evolution of the entire global ATS system. Unless these RNP based trajectories can be appropriately flown 3D and later 4D, with relevant speed and eventually RTA, NET, and NLT constraints, using many if not most procedures with LNAV and VNAV RNP based RF legs at low RNP, then there is no hope of economically and successfully solving NextGen or SESAR.

This is the fundamental reason why RJs are now causing such enormous pain in the entire present ATS system, and for ANSP ATS system evolution globally. Because no known RJs so far can safely, reliably, and with redundancy fly these kinds of accurate RNP based procedures, and especially not with evolving RTA elements. That is why coordinating mutually exclusive efficient RNP based flight paths into, and out of places like KSEA, KSFO, KORD, and KMDY, and KLAX, and KDFW, and KLGA and KJFK and KEWR is so terribly (and unnecessarily) difficult.

Bottom line is that no known RJs can yet do this. AT performance inherently relate to lateral and vertical profiles, and that interaction matters. And until RJs can do Real RNP at the needed low values, then successfully and economically solving and evolving ATS, at any affordable cost to users, and with the needed capacity increases, and ability to address WX deviation flexibility, is virtually hopeless.

As to "lights out", ...understanding why all this matters, may be key to your future operator and employment survival, let alone safety, ...in particular for those who may be following this thread, and who are not already retired...

Q.E.D.

[A320 CURSED]

Ozymandias gave you the absolute correct answer.
Adv the Throttles as needed just forward of CLB detent till back on VAPP, then return them back to CLMB detent and everything "managed again"


Or pull the Speed knob and increase speed to "selected" for the auto-thrust to increase THR to the new selected speed.
You can also disconnect the ATHR, and be careful you are clear with that procedure or it may bite you.
Airbuses are not dead busses, they tend to scare pilots which are not proficient on the stated procedures in the FCOM/FCTM.
I have flown both 320 & 767 and like the both, they are just different and the airbus is less forgiving on "sloppy pilots" period.

[peekay4]

This discussion relates purely to those kinds of RNP based procedures, and is a subject for which no current BizAv based avionic system, as typically used in any RJ presently flying, comes anywhere close to meeting RNP.1 capability
Huh? Numerous business jets today are fully certified for RNP 0.1 approaches (including those with curved segments). E.g., Gulfstreams equipped with Honeywell Primus, Bombardier Global series (with Rockwell Collins), and Cessna Citations (Garmin) all include full RNP 0.1 approach capability available as options. Some, like Cessna, include RNP 0.3 as a standard feature.

So it's not a technology issue but whether or not specific customers require (and is willing to pay) for the capability. The reality is that new business jet avionics tend to be superior than your typical airline fleet avionics.

In Europe, trial RNP curved approaches were conducted on a CRJ-1000NG operated by Air Nostrum.

Since you mentioned PAJN, note that Horizon has been flying curved RNP 0.1 approaches there on their Q400s, mere turbo-props!

And in any case the refreshed regional jets coming up (Embraer E2, Bombardier CSeries, etc) are all orderable with RNP 0.1 as options.

[Chesty Morgan]

Since you mentioned PAJN, note that Horizon has been flying curved RNP 0.1 approaches there on their Q400s, mere turbo-props!


With no AT!

[7478ti]

Not all RNP .1 is equal. Those aircraft types and procedure examples you cited come with significant RNP related procedure operating constraints or limitations. I can cite specific examples, having tried and failed to make some of those systems work for both OEMs or operators. Even the excellent work done by Horizon (led by Perry S and Steve B... ) on their Q400s, to make an otherwise seriously deficient box at least try to mimic real RNP, to some extent, and partially work, is only very primitively successful. For example, NONE of those types or avionic systems have yet demonstrated capability for suitably flying any of the kinds of real RNP procedures that I cited earlier, such as at NZQN, etc. A few of them are reportedly going to potentially try, with still "in the future" attempts to be modified to evolved versions of those avionic systems, but NONE currently can yet can perform these cited RNP procedures adequately. Just because they have a magazine ad promoted PR label, claiming RNP capability, or even "RNP .1", doesn't necessarily mean they actually can safely fly any of these real RNP based procedures, and particularly not when addressing the needed rare-normal or non-normal conditions. In fact a few OEMs are now getting a rude awakening by purchasing some of those systems for their new types thinking they're getting comparable systems to the big jets, only to find those BizAv related systems have serious RNP related shortfalls, to actually be able to do the job, even if they advertise RNP capability.

[peekay4]

You've lost all credibility with your post there, 7478ti. :*

There are dozens of business jet operators today flying RNP AR on a regular basis.

In the US, Part 91 and 135 operators with LOA are authorized to fly all published FAA RNP AR procedures down to RNP 0.1 limits depending on the aircraft's capabilities. Every single one of them, as the authorization is not "per approach".

Unless you're suggesting FAA RNP AR approaches are not "real" RNP. :ugh:

[Denti]

Quite a bit off the track here. As far as i know a subsidiary of ours was certified to fly the curved RNP AR approaches into Innsbruck and Salzburg with their E190, same as we did with our 737-700s. Whereas our A320 fleet is still not certified for anything below RNP 0.3 and is not RNP AR capable. Not no mention that the autoland crosswind limit on our newest just delivered A321 is still only 20 kts, which is even less than our 10 year old 737s who can do 25kts in fail operational approaches.

Quite honestly, the E-Jets are pretty nifty with their autoland capable autoflight system, even more so if equipped with the dual HUD setup.

[Chesty Morgan]

Remember not all RNP 0.1 is equal. I suspect your curved approach won't be curvy enough to satisfy 7478ti. ;)

[Smilin_Ed]

That anyone is even having this discussion is frightening. :eek:

[No Fly Zone]

1. Learn how to Hand-Fly your airplane.
2. Pay attention to the instruments AND the visuals.
3. If you need to go faster, PUSH a little;
4. If you need to go slower, PULL a little.
5. Practice a few times and you can learn how to Hand-Fly almost anything.:ugh:

[Uplinker]

NFZ:

Agree with 1. 2. and 5.,

but 3. and 4. don't work like that in a FBW Airbus, which I think is the point.

[RAT 5]

I wonder how long before FBW cars are the norm. Car goes faster/slower, but accelerator pedal doesn't move; same with brakes. I wonder if the pedals will still exist, but there has to be a 'manual' over-ride. Side stick, central, FBW steering. It is all technologically possible and possibly, once certified & produced to a suitable economy of scale it will financially viable. There is already active cruise control that includes braking sensors; there is automatic parking, auto wipers & lights, massage seats and voice controlled radios & phones. You could have 'scream activated brakes'
In 20 years we may be having similar discussions about the degradation & dilution of driving skills. However, I suspect there will be many more smoking holes before they realise that all is not well and the basics are still the basics and should be taught with a vengeance.

[Intruder]

MANY newer cars have electronic throttles, but the foot pedals still move. AFAIK, most brake pedals are still mechanically connected to the booster unit.

[vilas]

Not FBW but By Wire already exists in cars like speedometer etc. Brake by wire is there in formula1 cars. I am not sure about aircrafts.

[peekay4]

Actually the 2014/2015 Infiniti Q50 sedan is already drive-by-wire ("steer-by-wire"). Toyota / Lexus has sold brake-by-wire cars for over 10 years, starting with the Toyota Estima hybrid in 2001.

On the Infiniti Q50 there is no mechanical linkage between the steering wheel and the tires. The Q50's "Active Lane Control" can make corrections to your driving input to help you stay in the lane in case of strong crosswind, poor road conditions, etc.

Closer on topic, coupled with the car's Auto-Throttle (aka cruise control) the Q50 can completely drive the car for you:

Infiniti Q50 Active Lane control is scarily self-driving (http://www.autoblog.com/2014/08/06/infiniti-q50-self-driving-video-autobahn/)

(Notice however the poor auto-pilot disconnect warning at the end)

The Infinity Q50 A/T will adaptively adjust to the speed of the cars ahead of you and maintain appropriate distance (or applying emergency braking if needed). Sensors track, detect and anticipate two cars ahead -- the car in front of you, plus the next car ahead of it.

The controls are intuitive. The A/T below Vspeed-limit? Just hid the "accelerator pedal". If it's going too fast, there is a "brake pedal" provided. :}

There have been a lot of innovations on the car side which will eventually be brought back to the aviation in the form of NextGen, e.g., for sequencing flights on approach to land.

Starting at $37,150 at a dealer near you. :E

[megan]

From BEA Cautions Authorities On Legacy Airbus A320 Guidance Computers | MRO content from Aviation Week (http://aviationweek.com/mro/bea-cautions-authorities-legacy-airbus-a320-guidance-computers) I note the priority button features again, or lack of use thereof.

The French civil aviation investigative authority, BEA, is asking EASA and Airbus to consider issuing an airworthiness directive that would force operators of hundreds of Airbus A320-family aircraft to replace legacy flight management guidance computer (FMGC) with an updated version.

For aircraft equipped with those systems, the auto throttle will incorrectly increase thrust when approach speeds are too high at 50-150 ft. above the ground, exacerbating the speed problem. Airbus learned of the problem in 1996 and introduced an improved FMGC in 2001, but airlines have to pay for the new equipment. To date, the change-out has been voluntary.

The auto throttle issue gained renewed prominence in a July 2013 accident involving an Hermes Airlines A321 that overran the runway at Lyon Saint-Exupery in instrument weather conditions after a too-fast, unstable approach. The aircraft, operating as a charter for Air Mediterranee, touched down 5,300 ft. past the threshold and exited the runway 1,000 ft. past the opposite threshold, damaging the engines but injuring none of the 174 passengers or five crew members.

BEA, in a final report issued on the incident, named a number of causes for the accident, including the inexperience and training of the first officer (the pilot–flying), the failure of both crew members to abort the unstable approach while in the air or during the extended flare above the runway, the fatigue potential of a 15-hour workday and the pilots’ lack of understanding of the control sticks.

During the flare both pilots were attempting to control the aircraft, with the sum of the inputs sent to the elevator control, rather than the captain taking over.

An analysis of the autothrottle revealed that the improper increase in thrust just before landing could have added as much as 1,600 ft. to the distance the aircraft traveled before touching down. BEA says none of the previous operators of the aircraft—Swissair and Air Mediterranee—had opted for FMGC replacement, and Hermes has been unaware of the issues when it purchased the A321.

Following the Lyon overrun, Airbus issued a special bulletin to alert operators equipped with the legacy FMGC of the issue. In June 2014, Airbus told the BEA that “operators were studying the proposed replacement. This concerned about 250 aircraft, and 36 of the aircraft were modified.”

BEA is asking EASA and Airbus to “define a period following which it determines” the effectiveness of replacement actions taken by airlines. “Without feedback from operators on their decision to replace the FMGCs concerned, it could then consider issuing an airworthiness directive,” BEA said.

[Uplinker]

Very interesting. I wonder if that applies to the A330 as well?

The quoted report talks of a thrust increase just before landing, and I wonder if perhaps the F/O - who sounds inexperienced - did not retard the thrust levers in the flare? If the thrust levers are left in the CLB gate too long, there will be a power increase as the A/THR tries to maintain Vapp, and this can cause a long float.

[peekay4]

The quoted report talks of a thrust increase just before landing, and I wonder if perhaps the F/O - who sounds inexperienced - did not retard the thrust levers in the flare?
The A/THR applied thrust increase long before the flare (at around 150ft AGL).

The plane was already at least 10 kts over the 141 kts Vapp at the time and the A/THR bug accelerated the plane even further, to 163 kts by the threshold according to the report. Plus there was a +7 kts tail wind.

But lots of other things went wrong on that flight. The plane was never stabilized (Vapp+47 kts at 1,000ft), the crew contradicted each other (even though the Captain was a CRM instructor), both were manipulating the sidesticks after the flare, the thrust levers were retarded late (only after the RETARD annunciator), etc.

The plane ended up touching down 1,600 meters (!) past the runway threshold at 154 kts ground speed.

The crew training was also shockingly poor. The F/O reportedly didn't know what the airline's stabilization criteria was, and couldn't explain the meaning of the characteristic speeds (green dot, F, S).

Similarly the Captain allegedly didn't really know the stabilization criteria, missed approach requirements, proper emergency evac procedures, etc.