Except that Airbus has been and is a big pusher for more automation and expects its crews to rely on it.
Even TCAS maneuvers to be soon flown under full auto ...

Did you notice how the guy is talking about disconnecting auto thrust : click click - Airbus has made it different, it used to be really simple but now you need to think to do it the correct way.

where did I hear that before
 

video @ 21:50,

Commenting on the 757-767-A300 piloting community,
"What's it doing now?"
Specially for those that think this issue only came up first with the advent of FBW in the A320.

Nice video BTW, good advice for all pilots no matter what type they fly.

I don't know the design parameters of the latest Airbus's but the 310 had a vicious go around compared to the Boeing. The Boeing will maintain 2000 fpm while the AB goes to full thrust. If the airplane is light the attitude is way high in the Bus and it is necessary to cancel the auto thrust if you want to make it more reasonable (for passenger comfort perhaps).
China Air lost a 310 when the pilot, while doing a go around on auto pilot, pulled back the thrust levers to reduce the rate of climb and climb attitude, which led to a stall. He was slow to turn off the auto pilot and recover and the airplane only just managed to make level flight at less than 100 feet agl. Unfortunately, there was a 150 foot building in front of them. Sad. The pilot was one of their best, too, and he had his wife and kids as passengers.
Other than that, the 310 is a great airplane, pre fbw.

In my opinion a crazy and dangerous idea to have an aircraft that is not speed stabile.
This is not an Airbus vs. Boeing thing. This is Airbus against anything that has otherwise ever been build. This FBW itself it not a problem, it's the way that they implemented it.

With a conventional aircraft that is in trim, the nose would pitch down to keep the trimmed speed (unless active back pressure on the controls). That the speed just decays until protections (hopefully) kicks in seems like a recipe for disaster.

Like with AF447, the F/O held the stick back the aircraft actually trimmed itself to fly 60 knots or the stop of the stabilizer, because the protections didn't kick in. A back pressure which in itself would have felt highly unnatural in a conventional aircraft, since a significantly pressure would be required (here only the force of a tiny spring or whatever keeps the stick centered when no force is applied).

In a conventional aircraft no one would ever have held full up elevator, simply because it would have felt unnatural and uncomfortable requiring quite a bit of muscular power. Secondly the stabilizer would not have moved and third the aircraft might have recovered on it's own as soon as someone had let go of the controls.

Makes you wonder how it ever got certified!

I did indeed notice that. However back then when I flew the A320 I never felt this was much of a problem; sure, you need to adjust the thrust levers with the 'donuts' prior to disengaging autothrust - otherwise you'd be in for a nice increase to climb thrust - but I never thought of it as another step I would to really have 'think' about. I just did it.

On the other hand I have to admit that I can imagine pilots not having flown Airbus before having some difficulties adjusting to that.

DBate

Another one is that TCAS procedure where not one but both FDs need to be switched OFF in order for the autothrust to turn to SPEED mode.
From a straightforward procedure as described in the video : click click - click click it is now click click on the AP only + both FDs OFF + FMA confirmation you really get what you're looking for.

I just question if things are that better ...

Where did this come from ? I thought it mandates AP off, both FDs off, then follow TCAS aural commands (at least in the A320 anyway).

Its from the A380 and can be retrofitted to other types via a FWC upgrade... This is old news... Was in the Airbus pubs back in 08/09.

PT6A, thanks. Now I can just sit back and watch planes fly by ... :ok:

I know! Pretty neat.... Weird to watch it in the sim the first time

Protections don't hopefully kick in on the bus, they do if you're in normal law and they don't otherwise.
That said, in alternate law (what AF447 had) the aircraft will start shouting STALL when you get to vs1g, and the auto trim ceases to function which essentially gives you a speed stable aircraft again.

But I guess it's more fun to bash the "scarebus" than to try and understand it's logic.

Hi,

:ugh:

Suggest you understand it. "Houston, we have a problem!"

That's the problem, isn't it - when **** hits the fan over the Atlantic you have to think instead of instinctively react. Apparently even experienced Airbus pilots have problems understanding the "logic" (misnomer?).

The pilot has to adapt to the engineers idea of a good aircraft, instead of a design that is build around what is natural from a pilots point of view. This is a prime example of poor engineering!


I am not saying that it can't be flow like a normal aircraft or that it is not pleasant to fly (can't speak intelligently about either since I never flew it), I am just saying that when things go wrong, it's a bad concept - like numerous accident have proven, most lately AF447 and the Perpignan test flight (incidentally both due to sensor failures and stabilizer trimmed to full pitch up without pilot knowledge as contributing factor). Then there are all the close calls, like zoom climb and subsequent stall due to a simple overspeed, aileron deflection that reduces after touchdown in x-wind without pilot knowledge, aircraft dropping several thousands of feet because a box goes belly up... and what have we not.

Try to convince me once again that we should just "understand it's logic". :hmm:



All that said I sadly prefer to fly Airbus when flying as a passenger, considering the deteriorating skills of pilots, I have more confidence in the computer not breaking down, then someone up front having to deal with an engine failure while hand flying. :ooh:

Pulling up is the instinctive reaction to counter a stall? I didn't think so either.

I don't know why the crew reacted the way they did, I can only speculate that in addition to severe disorientation it had to do with the way they were trained, probably to be "children of magenta" a problem which is common to all modern aircraft these days...

A320 v 777
 

I have limited experience on Boeing and Airbus (B737-200,300,400, 747-100,200, B777 - A391,320,321 - 22 years in all) and test flew the airbus for a short time some years ago, and would just like to put your mind at rest.

1. The sidestick and flight control system on the bus can take ages to get used to - sometimes as much as 7 or 8 seconds.

2. You never need to manually take control of pitch trim, as the stick is basically an attitude selector - so forget about trim (excepting when in degraded modes without it, when it will tell you to trim, and this is then easy).

3. If you want something to worry about, worry about the manuals - they are a pain when learning the type, and the new acronyms take some getting used to.

4. If you want something else to worry about, worry about ECAM which also takes some getting used to.

That said, it is the most fantastic, comfortable, enjoyable, able aircraft it has ever been my pleasure to fly, and for the last 6 years on the 777 I've been missing an FMA that works properly, a FMC that can do a descent properly, and a flight deck that isn't cack-brown!

Logic?
 

If one must work at understanding the logic, maybe there is a problem with the logic.

Except for QF72

Except for AF447

Except for AF447 it did not.

No bashing, no scarebus either, just discussing facts.

babotika, I have to agree with CONF iture on his second point: It dit not in AF447, and in fact it's not a bug, it was "as designed" that the autotrim (up) was not inhibited at or below vs1g.

CONF iture, re: your 3rd point:
"Except for AF447 it did not."
Wrong exemple, indeed it did not for AF447, because it was not in the proposition:
"excepting when in degraded modes without it, when it will tell you to trim, and this is then easy"
It may not tell you to trim in one case: Abnormal attitude law.

(btw: I do feel that some parts (inhibition at vs1g, telling the crew in abnormal attitude law) of the trim logic may/should be enhanced on A ; but let's keep facts straight, shouldn't we?) :)

My theory:
(and yes it should be obvious by now that I don't like that Airbus philosophy, but at least I believe I have it backed up with arguments as to why)

I would say that in general, it is very natural to pull back when you are going down. You have to remember that not once in the CVR do they discuss the possibility that they are in fact stalled, despite the oral warnings. Hence, it would be quite reasonable to conclude that they were not aware that they had stalled.

With the first problem being unreliable airspeed, it may have caused them to subconsciously dismiss the warning. Further another Airbus "feature" may have enforced their belief that they in fact where not in a stall. As they pulled back and the speed dropped below 60 kts the stall warning seized.
Question: How can you design a stall warning that stops when the airspeed get extremely critical? How can the "logic" dismiss a speed of less that 60 kts as being "invalid" when the air/ground sensor is in flight?
Rhetorical: Oh yes, I forgot, it's not necessary since it's obviously impossible to stall an Airbus!! (my bad, since: "we must try and understand it's logic").

With no tactile feedback from the stick (which would have presented itself as unusually high back pressure in a conventional aircraft, like mentioned in previous post), the only indication that something was terribly wrong would have been the high pitch presented on the PFD.

Another question: Correct me if I am wrong, but is the normal GPWS maneuver for an Airbus full back pressure and full thrust? Oh, they were in another mode where that doesn't apply, you say? ("we must try and understand it's logic").

Conclusion:
With the assumption that the aircraft is flying it is perfectly natural instinctive reaction to pull back to arrest a descend.


Of course It's unfortunate, to say at least, that they didn't recognize the high pitch, but with turbulence, bell and whistles and an aircraft providing no feedback what-so-ever I won't be the judge of that. From reading the transcript it seems like they got really confused and overloaded, and they certainly didn't get any help from the aircraft.

Surely, the situation could have been handled better with pitch and power, but with daily ops with "path stability" and other concept that goes against the laws of nature, is pitch and power even a concept in the Airbus "logic"?

Lack of training... Yes, an inherent Airbus problem, since you can't make up the daily training on the line with simulator sessions twice a year. The problem with the Airbus in my opinion is, that you can't train flying it in alternate or direct law. With a conventional aircraft you can train "direct law" raw data daily, and this is the worst situation the automatics will drop you into. With Airbus on the other hand, when you have a problem on a dark stormy night, the aircraft itself drops another problem on you lap - that you get an aircraft that you are not used to handle and never will be properly trained to handle!
Of course this could be solved by mandating that all Airbus pilots get a simulator session pr. week, where they can practice flying in the lowest level of automation! (they would still get less practice then an eager pilot on a conventional aircraft).

To say that AirFrance managed to pair up the 3 worst pilots in their fleet and their incompetence was the cause of the crash is simply too easy a solution. Im am not buying it, and I feel sorry not only for those onboard but also for those the pilots left behind, who now have to live with the public pressure that their loved ones, who may have been dutiful and decent pilots, killed a lot of people.

Time for a re-post!
 

In case some of you didn't see this article when it was first posted:

Technique: The 'Panic Pull'

AOPA Online: Technique: The 'Panic Pull'
:eek:

Cosmo Kramer

Perfect explanation of the problem with the Airbus philosophy and its limitations. WRT to "goes against laws of nature", I offer this:

[QUOTE][For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled.

Richard Feynman
US educator & physicist (1918 - 1988)
/QUOTE]

GF

Perfect explanation? I don't think so, when a pilot can't relate attitude / ROD / ground speed, multiple warnings, the airplane will crash.

Has nothing to do with it as demonstrated by several accidents in Boeing aircraft with bad pitot indications. :=

I'm not an expert on the Boeing or the Airbus (but fly Airbus) but the thing that strikes me as odd in this thread is the fact that various causal factors in accidents involving Airbus are being attributed to the philosophy or Airbus, for various reasons.

However, as far as I can see, nobody seems to be attributing any Boeing accident to their philosophy. This is more than just Airbus vs Boeing, and I mention it because it seems to be a flaw in the argument of those who argue against the Airbus philosophy, when it's not beyond unreasonable thought to suggest that it was perhaps pilot error and not knowing the aircraft that was a causal factor, rather than purely down to the manufacturer.

For example, Turkish 1951. In some ways, it has its similarities with AF447. Lack of situational awareness, lack of monitoring and possible task saturation, for instance. After all, would that accident have occurred in an Airbus? I'd suggest not, since the sensing of the low energy state (SPEED, SPEED) or alpha floor would have saved the day. Is that an issue or problem with Boeing aircraft? Well apart from identifying the issues surrounding a faulty RA, I'd say not.

I do wonder whether some are blaming the aircraft when in reality, those in control should know their aircraft and the signs the aircraft they are type rated on will present in certain conditions.

I think it's probably "pilot nature" to compare the two (primarily if you've flown both!) but should we not know the basic characteristics of the aircraft and assuming the manufacturer has provided us with something sensible, be able to handle it in all conditions?

If the Swiss Cheese Gods align without appropriate intervention from the crew, then an accident will occur. You could go through most accidents and say "well....if they had this function / feature / attribute / characteristic then it might not have happened" but that's the nature of safety in an industry that has so many variables. The Airbus vs Boeing debate with regards to safety, is surely just another one of those statements...

DreamLand

First, I'll admit I haven't flown an Airbus, I do, however look forward to a FBW plane. But, WRT "multiple warnings", with each warning, th pulled on the side stick and what happened? The warning stopped, in a sense, they were rewarded by the cancellation of the warning and thought they solved the stall. Game Over! They hadn't been trained to assume there were TWO methods of stopping the stall warning--the usual way we all assume it works and the Airbus alternative by reducing airspeed below 60 knots.

I completely agree they should have been trained to see the whole picture and recover by recognizing the ROD and speeds.

Would the TU AMS plane, if it had been an Airbus with the same RA failure leading it to believe it was at zero feet, not have crashed, too?

GF

FWIW, over 3000hrs cmd time on Airbus. It does some things very well, and some things very poorly.

Non moving thrust levers are a pain, sidestick is not a problem as long as you are ok with being "disconnected" with the aircraft.

Screens, especially early ones, are crap. LCD screens an improvement.

Cockpit lighting, again better on newer models, garbage on older models.

No trim, good for some, not others.

Controls law, complicated but understandable. Not as clever as airbus like to think since electrical failures can drop you into the biggest pile of s**t imaginable.

Autothrust can be glacial in response to demands, even when they are computer generated demands.

Main issue is the relationship between systems and how one, seemingly innocuous, failure can swiftly develop into a whole miserable world of hurt....hence the phrase "What's it doing now?"

Overall, Boeing!:ok:

Hi galaxy flyer,
Yes it would.
From OEBProc-38

"During ILS (or MLS, GLS) approach with AP engaged, in the event of an
unexpected early THR IDLE and FLARE modes engagement, the flight crew must immediately react as follows:
‐ Immediately perform an automatic Go-Around (Thrust Levers set to TOGA),
OR
‐ Immediately disconnect the AP,
‐ Then continue the landing using raw data or visual references (FDs set to OFF),
OR
‐ Perform a manual Go-Around (Thrust Levers set to TOGA). Significant longitudinal sidestick input may be required.
Note: 1.If the flight crew does not immediately react, the angle-of-attack will increase and may reach the stall value."

RRR and OK465

I'll let you two fight it out, but it seems to me with an RA below some value (50'?) the Airbus must go into a landing "law", else it never would land. Or is there an algorithm that looks at RA and pressure altitude for just this case and negates the erroneous RADALT? The TU B737 had an essentially 0' RA for sometime during the approach, sending the autothrottles in RETARD mode. I suspect the TU plane, if an Airbus, would have looked similar to Habesheim, no?

GF

PS: Just a dumbbell cable 'n fluids pilot, not too sure why we need to computer whizs to fly.

aa73, I had the pleasure to fly MD 80s for ten years before hopping on the bus and I must say that the good old MD felt like "my wings", we where one once I strapped in and the JT8s where running. Then came the A 320 course and after 10 minutes in the Sim I loved the fly by wire, the comfy office and all the electric gismos. Today, after 11 years of "busdriving" I still don't miss moving throttles or flightcontrols at all. Airbus has "golden rules" and No. 1 says: " This aircraft can be flown like any other aircraft" and they are right. You can treat it like a proper aircraft and it will do anything a conventional aircraft does, plus a lot more.
I hope you will enjoy it as much as I do!

Hi OK465,
I don't think so:
FCOM DSC Aircraft systems, 27, 20, 10, Pitch Control Protections.
"The αfloor function is available from lift-off to ​100 ft RA before landing."

Same as Habesheim.

AZR,
For AF447 the trim did not reach the stop when actually the sidestick request was still there. In the meantime the BEA has not communicated about any USE MAN PITCH TRIM PFD MSG and dixit BEA, Abnormal Attitude Laws have not been triggered ... so what's going on here ?

• Why the THS did not go to the full UP position ?
• Is it possible for any reason the autotrim stopped working ?
• If so has the crew been advised through a PFD message ?

I think some questions deserve to be asked.

Conf sorry I'm muddled, are you saying auto trim should continue to work in alternate law below vs1g - i.e. while the aircraft is stalling? FCTM doesn't agree.

The aircraft was in alternate law, it's stated in the report date 1/6/2009 at 1.16.4.2 (P40)

Stall warning logic.
 

this was not the - Airbus Stall Warning Logic - it was the ADIRUs which invalidated the AOAs.....

Boeing drivers, be prepared,

B777:

The AOA will be invalidated if the CAS <30 kts = NIL stick shaker......
Don't rely on your SAARU because it already did quit at CAS <50kts
and Yes this is true when the air/ground sensor is in flight!

How is it possible then you are not aware your Airbus will not trigger Alpha Floor below 100 feet RA erroneous indication or not ?

SPEED SPEED SPEED would remain available for a 320 but not for a 330 … Go and figure ?

Are things really that simple in the Airbus world … ?

Not I would expect but still what AF447 did ... up to 13 degrees up.

Hi OK465,

Sorry the only information I have is from my current FCOM. (My bolding)
What's your latest source?

FCOM OEB 201/2 says:
!Erroneous Radio Altimeter (RA) height indication
APPLICABLE TO:
All A318/A319/A320/A321 operators
... other pages of faults and explanations ....

Warnings / Callouts
-
Untimely Terrain Awareness and Warning System (TAWS) alerts
-
Untimely or absence of “RETARD” callout
-
Untimely L/G GEAR NOT DOWN ECAM warning
-
Absence or interruption of RA automatic callout (height announcement)
-
Activation of AUTOLAND warning light in ILS (or MLS, GLS) approach (Refer to FCOM 1.22.30) with AP engaged in LAND or FLARE mode when:
o
One RA height goes below 200 feet and
o
The difference between both RA height indications is greater than 15 feet
Note: There is no ECAM message or audio warning in association to the AUTOLAND warning light. The AUTOLAND warning can be triggered even if AUTOLAND is not planned
Auto Flight System mode changes (indicated on FMA)
-
NAV mode engagement not possible after take off
-
During an ILS (or MLS, GLS) approach, and depending on the engaged Flight Guidance (FG) modes, the consequences may be:
o
Untimely/early engagement of the LAND / FLARE / THR IDLE modes if the RA height used by the FG is erroneous and lower than the real height.

Note: During ILS (or MLS, GLS) approach with AP and A/THR engaged, THR IDLE (RETARD) mode untimely engagement will be associated with an initial pitch attitude increase due to FLARE mode engagement.
o
In AUTOLAND, the LAND / FLARE / THR IDLE modes will not engage, if the RA height used by the FG is erroneous and higher than the real height.
o
In case of Go-Around and if the RA is still frozen at a very low height indication:
–
SRS and GA TRK modes engage
–
NAV, HDG or TRK lateral modes cannot be selected
–
LVR CLB will not be displayed on the FMA at THR RED ALT
–
ALT* and ALT will not engage at FCU altitude
Disconnecting AP and resetting both FDs enable to recover basic modes (HDG and V/S).
During an ILS (or MLS, GLS) approach with AP engaged, if an erroneous and very low RA height indication occurs, THR IDLE and FLARE modes may engage early with the following consequences:
-
In CONF FULL, the High Angle of Attack protection is not available. As a consequence the autopilot will not automatically disconnect at α prot +1°. If the flight crew does not immediately react, the angle-of-attack will increase and may reach the stall value.
-
In configurations other than CONF FULL, the High Angle of Attack autopilot disconnection is available. The autopilot will automatically disconnect at α prot +1°.
-
Loss of ALPHA FLOOR.
-
The LOW ENERGY AUDIO WARNING – “SPEED SPEED SPEED” - remains available. In case of activation of LOW ENERGY AUDIO WARNING, the flight crew must react as per procedure (QRH 2.03).
-
In CONF FULL, the auto-trim function is inhibited.
-
In manual flight or after AP disconnection, significant longitudinal sidestick input may be required."

If only No1 AP is engaged with No 1 RAD ALT giving erroneous readings of below 30 feet, then the above may occur.
With no Alpha Floor - that sounds like Habesheim to me.

How the heck could anybody just sit there and watch it?

Not totally as the difference between RA readings will trigger the AUTOLAND warning light for an ILS approach.

Except from being on an ILS approach, none.

As per the OEB as quoted by rudderrudderrat the consequences of an erroneous RA indication for the Airbus are numerous and surprising ...
Anyway, it is a long stretch to affirm that the AMS event would have ended differently if the aircraft was an Airbus ...

CONF iture:
SLF checking in again:
I've said it before and I'll say it again--

I will NOT get on an AB, ever. I want a plane that can be flown (and landed) by a well-trained human being without undue confusion or SURPRISES. The above is frightening, given the cut-rate training on some airlines.

Hi Organfreak,

I hope you don't really mean "I will NOT get on an AB, ever." because of something you've read here.

The advantage of sharing mental models on PPrune of how we think some remote failure might affect the aircraft, is that we learn from others. It would be a shame if we stopped because it was having an adverse effect on the travelling public.

Please rest assured, the vast majority of us learn something useful here and are better prepared to "take control" when needed.

Rudderrudderrat and OK465,
Thanks so much for your thoughtful replies. Sure, I expect that most pilots posting here are the cream of the crop, given their obvious interest in learning and even self-examination, IOW, intellectual curiosity. I would fly with most any of you if you could show me your official PPRuNe Membership Cards first! :)

I doubt that I've done much damage to AB's reputation by saying I'm scared to fly on one. I think they're already quite familiar with this attitude (pun intended). But, I'm a firm believer in Murphy's Law, which is, of course, what caused AF447 to get all broken.

I know one pro 767 driver who doesn't come here for the reason that "it gets too technical." YIKES! How many pilots are like that?