bubbers44

I don't think it would take an ace to know at 35,000 ft you can not have the yoke in your gut. The PNF would have reacted but with the SS he didn't.

bubbers44

No it doesn't but if you are talking about visual scan I think the yoke being full back would make you react immediately leaving 35,000 for the impossible climb to 38,000 at the rate he was climbing before noticing the attitude indicator, don't you? They were too heavy to climb to FL370 because of weight and temp in turbulence so 1.3 buffet was their chart to climb.

Even if they used the AB 5 degrees nose up climb power memory items at their altitude it wouldn't have worked because unless they leveled out immediately they would have been too high and too slow and violated their RVSM separation.

bubbers44

I was responding to a momentary reply that is now removed about why the attitude indicator and 38,000 ft wouldn't have clued the PNF.

CONF iture

And it is interesting to note that there is still no trainer in flying school equipped with such independant SS, probably for that very reason.
But now guys arrive on the RHS of a 320 with virtually no flight time at all ...

Question for you or aguadalte or RF4 or anyone who seems to share my view how the Airbus concept suppresses valuable information : What made Airbus to embrace such philosophy ?

bubbers44

Cost is my guess. I was able to bid away from AB so didn't have to leave Boeing planes my whole career. Loved Boeings because you always had control. Two button pushes and you were a DC3 style airplane. You were 100% in control. It made flying easy.

CONF iture

You could still have given a try and like most of us you would have loved it. With time and perseverance we learn step by step what’s inside and how to master it and recognize the weak points. Of course you can still fly it like a DC3 except you’re not allowed to force direct law, so you’re still vulnerable to a Qantas mishap ... but what are the odds after all.

Old Carthusian

I am still left with the question - would a yoke or visible side stick have helped in this accident? The conclusion given the information we have is no. The PNF had all the information he needed and didn't need to guess what was happening from seeing the position of anything. Gentlemen this is just clutching at straws and displaying your prejudices not objective examination of the situation. Look to the psychological and 'soft' features of this accident not whether you can see a side stick or not. Instruments, gentlemen, instruments.

gums

The lack of visual cues or "feel" of the other pilot's control position is a bogey man.

You see what the jet is doing and question the other dude/gal and then get in the loop.

I have soloed dozens of troops in the Viper with the sidestick and zero feedback and zero stick movement ( actually about 1/8 inch after first few came on line). That's the family model. In the SLUF we had no two-seat trainers so first flight was solo. Flew close chase and talked to the troop.

As several here have stated over and over, it's the instrument crosscheck and determining if the jet is doing what it is being commanded to do, or not.

bubbers44

Ask any normal flight instructor how he would like to teach basic flying and see what they say. You need visual feedback of what the controls are doing. Once you have an advanced student you might get by with no visual feedback.

Old Carthusian

However, this is an advanced flight situation - not a basic training exercise. No visual cues outside the aircraft at all.

Lyman

I think bubbers44 meant cues direct from controls, not outside.

Mr Optimistic

Surprising that the cmd didn't command the pf as to his action and ask, repeatedly, what he was doing. On the evidence, could an assertion that all the crew were aware of the pf inputs be refuted ie there was a consensus in the fd? All the ss discussion seems to be that the pf was a secretive incompetent renegade and if only the others had known and acted!

And if the pnf had to get up to let the cpt in, why didn't the cpt immediately take his seat ? The mystery of the undone straps was never resolved was it?

aguadalte

CONF iture:
The provocative answer to that question would be: "because Airbuses were designed by engineers but unfortunately flown by pilots"...
My personal guess is that they wanted to brake with the "old" concepts. Starting with a blank sheet, they wanted to show the world that they were able to design an all new aircraft reflecting the European potential for innovation. "An aircraft made against pilot's errors"...
I had the opportunity to meet Pierre Baud, when I was invited to Toulouse in the early ninety's, to fly one of their A330 testbed aircraft. That was my first experience with a FBW aircraft (before that, only Boeing and A310's) and I personally had the chance to verbalize my worries in this regard (no feed-back on SS, added inputs on SS, lack of need for trimming, ATS in step of Auto-Throttles) and he explained to me that this was a new concept of aircraft and that the FBW represented not only an evolution on the handling characteristics but also the chance to save on weight and that the final goal would be MFF and communality.
I do understand that at certain point of the design work, AI engineers had to take options. They have opted for this system and there is no go-back, at this time. It is not yet clear for the majority of the pilot's community that the system is wrong. There's a great deal of pilots feeling quite comfortable flying SS without feed-back, but as Donald A. Norman wrote on his:

A33Zab

The automation was made less intelligent with ALT LAW (PROT LOST),
the human (pilot) was in control...but failed.

Conclusion?......green light for MORE automation.

DozyWannabe

It's always distressing when everyone's talking and no-one takes a second to listen:

Diesel8

"It is not yet clear for the majority of the pilot's community that the system is wrong."

Oh really?

If the accident/incident rate were different between AB and Boeing, then you would have a point, but as we know, it isn't.

I hate to ask, but I surmise you do have time on the bus?

CONF iture

Thanks for the reply aguadalte. Interesting.

That kind of aircraft is so dependent of the quality of the inputs received through the numerous probes. If a doubt exits on any of those probes or sensors, the aircraft should reverse straight to the most simple law : the direct one and get rid of any kind of automation. To have quietly autotrimmed 13 deg NU under those conditions has been a killer.

That's the advantage of fully visible yokes, no need to wait or ask, you are continuously in the loop.

Again, it has never been question to doubt what the instruments are telling.
It is question to know what has been commanded, or not. How do you know if you can't be aware of the command inputs ? Maybe the aircraft is doing something that has not even been commanded by the PF.

Fully visible flight control commands place you one step ahead in the thinking process.

Flyinheavy

@CONF iture


I share some of your views, but this statement seems a little strong, as it has been showed by BEA.3 that PF did use N/U SS inputs nearly all of the time for whatever (wrong) reason.

Means I would concur if he would have tried to overcome a NU trimm with N/D inputs...

Diesel8

I don't recall many incidences where the SS bus has not responded appropriately to sick movement, one that comes to mind is the cross wired stick, that reversed roll. F/O took command and landed safely.

As for AF447, the PF almost continuously applied nose up, when he applied nose down the A/C responded.

After all this discussion, I still cannot figure out why the pilots managed to stall this aircraft, it seems it was a simple case of loss of airspeed?

DozyWannabe

If - and *only* if - you see them. Many haven't.

CONF, if you only ask people who already agree with you, you're less likely to learn anything new. Most of the useful stuff I've learned has come from people who either agree partially or don't agree with me at all.

Pretend this isn't coming from me if it helps, but at least one of the reasons for the switch was that the yoke was designed around cable control. Before hydraulic assistance you needed a control column that size to have the leverage to move the flight surfaces. The 737 still requires it because it's manual reversion mode is cable-operated. None of the widebodies did, as they were fully-hydraulic, but it was kept anyway with a complex electro-mechanical feedback system in place. Same with the 757. The 777 and 787 use a software-controlled feedback system, the code for which is in all likelihood more complex than every system on the A320 put together. The A320, like the 757, was a narrowbody that was fully-hydraulic, and therefore one of the main reasons for having a yoke was no longer there.

With a fully-hydraulic system, one of the main reasons for having the controls interconnected - i.e. the need for both pilots to exert leverage when control cables are damaged - also goes away, so Airbus developed a system that would attempt to enforce one pilot in control at all times. Being an airliner and not a trainer, the need for one pilot to feel what the other is doing was greatly reduced, and losing the interconnection also removed the possibility of pilots fighting over the controls or having to work against the force exerted by an incapacitated pilot's body interfering with the yoke.

Being able to see the primary flight control movement buys some time, but only a matter of a second or two, if that. And if a PNF is really unsure about what their colleague is doing, they can take control at the press of a button and lock them out by holding it down (although would only be recommended in extreme circumstances - e.g. EgyptAir 990).

If you come at the problem having already concluded that the yoke is a superior control method in every sense, then you don't find this stuff out because you don't want to. Similarly if someone were to come at it from a conclusion that the SS is better, then they'd close their ears to what you're saying. Believe it or not, I do take on board the advantages the yoke has - but I don't think it's enough to say it's better or safer in every respect, because in some scenarios it clearly isn't.