CONF iture

That’s exactly what it is.
A/THR is disconnected to allow manual control of the thrust.
Nothing else.

To not be confused with :
L’autopoussée est débrayée de façon permanente afin d’inhiber l’activation d’ALPHA FLOOR.
A/THR is permanently disconnected to inhibit Alpha Floor activation.

FCOM
The A/THR system is disconnected for the remainder of the flight.
ALPHA FLOOR is lost.

Lemurian

This is absolutely typical of your tactics : selective quoting and selective memory.
You can't have it more than one way : either reject the whole report - as you've done in many instances - or accept everything in it.
On a previous post, I quoted the transcribed pre-takeoff briefing the captain gave the FO :
What is really tragic is that he planned a deliberate dangerous manoeuvre with passengers on board, without any preparation except what he'd seen Airbus test pilots perform routinely. All went to hell because, after all and in spite of his very high self-esteem, he wasn't up to the piloting task, never understood the vision geometry -at a high nose-up attitude- involved and eventually was responsible for the deaths of innocent people.
Had the airplane had anything sinister about it, it believe it would have been revealed... that 25 years later, there are still people to defend the most reckless flying with pax on board is totally beyond me...
Of course, I'm not naive enough to ignore that some do have a very definite agenda...

Lonewolf_50

I had the mistaken impression, when I saw a new post, that something about AF 447 (or some bickering about AF 447) was added to the thread, even though the blood has mostly been squeezed from that rock some time back.

The topic of this thread isn't the Habsheim crash.

It is AF 447, which conversation seems spent.

Respectfully request the bickering on the Habsheim accident be taken to a thread concerning that accident, gentlemen.

CONF iture

You are absolutely correct - I had already promised to do it ... as every Airbus event brings us in a way or the other back to Habsheim.
But there is no bickering here, there is only stuff that needs to be discussed.

CONF iture

Sorry Lonewolf, I guess I'll have to reply to Lemurian here as my thread on Habsheim is not accepted for now by the administrator.

Organfreak

Lemurian said to CONF iture:
I'm sorry, that simply defies logic. Would anyone here do the same with the BEA Report on 447? No, they would not. What is black-and-white about piloting? Nothing. I'll now return to hibernation. G'nite!

Lyman

I think there are important parallels, Confiture.

In both accidents, the aircraft had 'settled in', and the pilots, for different reasons, were unable to modify the flight path. Asseline had established a short final, and Pitch had the appearance of being on some mechanized value, sinking slowly as if to land, the engines did not change attitude, even though they had spooled up before the trees. Dozy is right, had the airplane Stalled, they likely all would have died.....

But it did not, it sank slowly as if to settle on the runway, having done the "retard" thing. Unfortunatley, there were trees on the 'runway'.

Had Airbus programmed their peachy "Escape" from CFIT at that point?

Question? Is TOGA escape available at the cruise levels? In ALTERNATE LAW?

Because at one point, 447 had flight parameters of a 330 on short final.

Unfortunately, she was above 38000 feet at the time, and ballistic.

TSR2

Having seen the recent documentary on the crash of AF447, one thing puzzles me. During the programme it was stated that the rate of descent was '10-15,000 feet per minute' and yet non of the three pilots seemed to be aware that they were in a stall until reaching 4,000 feet. Surely at that rate of descent the pilots would have felt something that may have given them a clue.

cwatters

Falling = weightless = empty feeling in stomach.
vs
Decending at constant velocity = 1g = feels normal.

They knew they were descending but not the reason why.

HazelNuts39

At what point?

Lyman

Nose high, sinking, approaching STALL, under power.

HazelNuts39

Sinking on approach to stall?

BOAC

....and silly me - there I was thinking they were already stalled too - what WERE they doing?

PS Don't fancy flying wiv 'im. Going up should be ok, but...................

Lyman

Howdy

HazelNuts39 Sinking on approach to stall?

Yes, though perhaps perceptually only, (reducing Vs)

'sinking' then. Let me add 'slow' As well. (<60 knots) With the STALL warn to seal the 'illusion'.......

Lyman

Hi BOAC


BOAC "..and silly me - there I was thinking they were already stalled too - what WERE they doing?"

With respect, it is of no consequence what you were thinking, v/v 447.

They were thinking they were not already STALLED.

They had no access to the data you have.

bubbers44

Lyman

bubbers44....

Thank you for that. That pretty much puts to rest the debate re: SS/yoke.
Sullenberger is not anonymous, and seemingly has no bias.

Case closed.....

TTex600 and CONFiture, a question.. From the video. Full aft stick shows the handle's remaining cant of approx twenty degrees forward. From this geometry, it would seem Airbus have incorporated a bias to back stick, and left NOSE DOWN as more difficult to gain v/v stick angle. Your thoughts? Full forward stick looks to require forearm push PLUS wrist rotation, is that it?

Is that an engineering artifact? A remnant of overconfidence in the aircraft's protection against extreme NU commands?

Full back stick looks alarmingly comfortable. is it?

HazelNuts39

No bias? I wonder.

Lyman

Hi HazelNuts39

"HazelNuts39
Quote:
Originally Posted by Lyman
'Sullenberger is not anonymous, and seemingly has no bias.'
No bias? I wonder."

You know, that is an interesting observation.... I think, pedantically, that any opinion is by definition a bias.

So it requires some critical thought...... He is a paid professional, and has been the owner of an Aviation Safety Consultancy for some time.

At some point, should scepticism be suspended in favor of practical purpose?

In my opinion, no my bias, I would say of course. In the video, he is sitting in the right hand seat, and we know he was a Captain, probably flying exclusively from the left side. Does that hamper his assessment?

The question addressed in the video had to do with visibility of the stick, as did BEA in their report, not interconnectivity. So we have BEA making a point of acknowledging the difference between Airbus and the Boeing architecture, and now Sullenberger more or less damning the layout as deadly, when compared in this way. (The accident would have been less likely, according to Sully).

I live nearby three Airbus pilots, all retired, who unanimously think the difference was unimportant to them.

The bottom line? What do the regulators and the operators think should be done, if anything?

For most folks a risk/benefit analysis suffices. What is the advantage of isolating the control devices visually?

gums

I had not seen Sully's opinion of the accident. Thanks for reminding us.

So I hear the narrator describing the onset of the accident - loss of the speed inputs and A/P disconnects. Then Sully talks about the constant back stick. As with Sully, most here will never understand the thinking of the PF. He may have still thought " I can't stall this jet".

So I posit we maybe should look at the A/P reversion modes as much as the FCS reversion laws.

In short, why not simply go to an "attitude hold" mode if only speed inputs are FUBAR? My archaic VooDoo had such a mode called "control stick steering", and was limited by AoA and gee. If you relaxed on the stick the sucker maintained an attitude, and not an AoA or gee. The AoA limiter would come into play long before the gee limiter.

For those flying the 'bus, just put in a tiny back stick that is commanding 1.1 gee versus 1.0 gee. And with all respect for Doze, the system commands a gee, not an attitude or AoA. The THS will trim to reduce the reuirement to hold that tiny back stick, right? But if I continue to hold it, the THS will move more and my pitch attitude will continue to rise. No need to hold full back stick. Just a timy amount will provide the same thing we saw with AF447's pitch.

So my idea is to look at the A/P reversion as much as the flight control law reversion. If the gyros/accelerometers are still working, then the crew has some time to figure out what's going on. No need to go "full manual" in a back-up control law.

What do the 'bus drivers here think?