AoA and side stick
 

Been lurking for a bit and finally had to comment about the AoA issue.

Flew only three jets with an AoA indicator - first had a big round steam gauge and we never looked at it unless we were maneuvering close to the "pitch up" boundary ( VooDoo), although we should have used it a lot more for approaches versus the 175 knots and 5 knots for each thousand pounds of gas above 3,000 pounds.

Second two had HUD's, and both had the AoA bracket once gear was down for approaches. The SLUF had it full time, but we only saw it when pulling a lot on dive recovery or a turning defensive maneuver. Viper only showed the "bracket" once gear was down, as we had the "protections" like the 'bus for AoA with gear up, heh heh.

As Smilin' and Retired and 'bird and OK have said, the AoA indication is really neat for approaches, as you can verify the T.O. approach speeds without lottsa calculations about weight and such. Simple crosscheck between the HUD speed and the AoA to ensure your configuration was correct, and I learned the hard way. Bumped flap lever before trailing flaps down, but leading edge flaps already down. So had correct stall protection AoA, but actual speed was higher than it should have been and I almost overshot the RWY.

Where the AoA indicator helps is close to a stall and on approaches, where you are - close to a stall!! Normal cruise or even moderate maneuvering doesn't require an AoA indication.

Looking at the 'bus displays, I don't know how you could put an AoA indication on the screens that would be easy to interpret/use. If there was a HUD, then no problem - use the "bracket" as we see in the Viper, Hornet, Eagle, Lightning, Jaguar, Space Shuttle, et al.

I have a hard time with commercial jets that don't have a HUD. Flying an approach in poor weather is so much safer and easier that I would demand it. A manual ILS is really neat with a HUD, and the Space Shuttle videos of their landings show how it works for their landing, so find some. Cross check with the steam gauges/ glass cockpit displays is real easy. You also have some neat things like actual inertial flight path vector, speed/altitude/vertical velocity right there on the sides of the display. So the AF447 crew could have seen the alt unwinding real easy, and the speed bouncing about from whatever to 107 knots.

Our dinosaur FBW ( father of the 'bus system) used the fixed stick and pressure sensors versus actual movement. This was because we routinely maneuvered at high body rates and gees. So having a moveable stick could have inadvertant inputs due to the forces on your arm. Despite concerns by the wimpy USAF HQ, it took us maybe 2 or 3 seconds to adapt to that stick once you rotated for your first takeoff.

Unless the AF crew was in severe turbulence involving high roll and pitch rates, there's no excuse for inadvertant stick inputs. The crew held back stick and could not fathom a stall that was so benign. No nose slice, no high roll to one side or the other, no extreme buffeting, etc. Of course, stall warnings and maybe overspeed warnings. Couldn't find the overspeed warnings in the BEA reports, but maybe that was a concern to the crew.

Chris Scott; TTex600;

Sorry about the confusion over the Google search string. I didn't check after posting, or I would have noted the url had shown as a link.

Anyway, the format is as posted by TTex600, e.g. 'search term' site : url, but the url needs to be the basic domain name without the http//: or www. Try the following by copying and pasting into the Google search box:-
- which returns all posts in pprune/tech-log by page number containing those search terms. (Note - had to place the terms in 'code' as the pprune site uses the colon when identifying 'smilies'.)

Back to the "armrest". From Interim Report No.3:-

Though this has also been discussed previously, both issues are inter-related.

It's interesting, but the fact that the cockpit remained populated in correct configuration, with pilots at the stick, and discussing other things,
may point to a lack of turbulence, or the disconnection of belts just prior to impact, something that sounds counterintuitive, but can be explained in a number of ways in connection with last second panic.

Who says the pilots died immediately? The "impact" reads as less powerful than Schiphol 737, with a better horizontal. If they survived the impact, who stays in a sinking barrel to drown? I'm off with my belts, and adios. What would Gus Grissom have done? Right....

Google searches of specific AF447 threads
 

The following Google search terms will enable you to search AF447 threads individually.

NOTE: Remove the [square brackets] and use your own search term, and there is no need to make reference to AF447, e.g.

- will return all the pages containing posts with those search terms in AF 447 Thread No.5.

- will return the pages containing posts by mm43 and/or posts mentioning mm43 in AF 447 Search to resume.

- will return the pages containing posts by mm43 only, in AF 447 Search to resume.

Use your browsers Find function and enter appropriate Search Terms to quickly locate the posts of interest on each selected page.

Finally, a search term to cover any subject on pprune will use the following:-

- and don't forget the thread search and site search functions available on pprune.

Infrequentflyer789,

To put things clear, I absolutely don’t 'actively dislike' the aircraft – Actually, I enjoy working on it, but I’m not blind. I have to accept I don’t know much on it. IMO Airbus made it unnecessarily complex and I’m well aware that I won’t necessarily understand what’s going on eventually and be taken by surprise.

What I do actually actively dislike and denounce, is the pseudo transparency from the BEA and justice. Why the judge refuses to include the full FDR data to the procedure ... ?

Aren’t we grown up enough to have a serious look to those data, maybe you and I are not Experts but surely they are some around here or elsewhere. It would be pure bonus for the BEA as truth is what they’re looking for ...

A long time ago, right after the stick, we invented the yoke. It was a big wheel like thing with no top that made it obvious what everybody was doing in the cockpit controlling the airplane. It made it simple to know what the guy on the other side of the cockpit was doing. It worked well for decades. It didn't matter much where the armrest was or if a different size person took over the seat. It was simple and self explanatory. Then a company came up with this idea they could save weight by putting this little side stick in the cockpit to do what the simple yoke system was doing. Now it isn't simple any more. Now you don't know what the other guy is doing so it is hard to respond when the airplane does something but you don't know why. Then you have laws of how all this works that some people don't understand. Now you have pilots that find themselves confused because they can't see the yoke moving any more like in the past. This is progress?

No reason to invent the wheel, fire should be enough for any caveman.

CONFiture.

"Why does the Judge withold data from the proceeding?" Who pays her salary? Not you, not those who benefit from truth, surely?

1. Those who would be harmed by the truth,

2. Those who DO pay her salary,

3. Both.

I am happy to provide perhaps the only transparency you will "see".

i think,the issue s/s or yoke is maybe a pschyological thing.
the yoke is something you can hold on,you can grab it with BOTH hands when in turbolence,it gives confidence b/c you are acting with your whole upper body.
you have a better feeling or the a/c b/c the motion of the yoke,the a/c and your upper body is in line.

ask yourself,who wants to drive his car with a s/s ?

google "site" search
 

For your info:-

mm43 said:
This seemed unlikely to me (google would surely just fix it so that it worked as expected in all three cases) so I tested the effect of prepending "www." and "http : // www." (spaces inserted to try to keep pprune happy as I seem to recall that it does not like URLs in posts) to one of the example searches. All three searches return identical looking results on the first page at least.

If this is off-topic then please feel free to delete it.

I, for one, don't have a problem with a SS. In fact, I love the SS. But I HATE not having tactile feel of the airplane.

The Airbus forces a pilot to interact with it entirely with his eyes and ears, but that's not really the SS's fault.

Which gets me around to the topic at hand. How a qualified crew managed to totally misread/misdiagnose their situation to the point of letting it kill them and theiri passengers. I think the "eyes only" interface has something to do with it. They were first faced with conflicting visual information, and then with conflicting aural information. This may end up being nothing more than an extremely unfortunate alignment of the "holes in the cheese". The list of factors will be long.

Cavemen may have done much better knowing what was going on by a yoke instead of a side stick. How would you react in a Boeing at 35,000 ft if the other dude pulled the yoke all the way back and held it there for several minutes? Would you request the captain to come back to the cockpit or intervene?

Outer Ailerons
 

As soon as AP did disconnect, Outer Ailerons kept the neutral position ... could it be a sign that IAS2 remained in the high speed range ?

@bubbers44 :

Much as I'd love to get back on the bit of the hamsterwheel where we're back to the ol' yoke-vs.-sidestick argument*, the fact is your hypothetical situation *did* happen, the Captain was there, and the aircraft pretty much pancaked.

Northwest Airlines Flight 6231 - Wikipedia, the free encyclopedia

[* - *Heavy* sarcastic tone implied... ;) ]

I would urge caution on that Wiki article "reaching a vertical acceleration of +5g" (in a spin!!??)

Page 7 of the NTSB report, (Page 10 of the PDF):

http://www.airdisaster.com/reports/ntsb/AAR75-13.pdf

So it's a peak value rather than sustained...

A misleading term - they mean load factor not 'Vertical acceleration' aka a Spiral Dive. Not a 'spin' as per Wiki

The point is that a three-man crew including Flight Engineer on a yoke-equipped steam-gauge Boeing 727 got themselves into exactly the same mess for very similar reasons, so to claim that the presence of interlinked yokes with feedback or an old-fashioned three-man crew would definitely have solved the problem is not true. Just trying to avoid another whirl on that particular hamster wheel is all. :)

Dozy

Your quote:
IMO, you are stretching the facts to support your ongoing theme here. There are more differences, starting with the get-go, than there are similarities, although the final results were the same, if that is what you meant.

IMO that's what a die-hard yoke-plus-steam-gauge fan would say. It'd be a funny world if we were all alike.

Dozy,

• In the 727 case, the 3 guys were in agreement to pull.
• In the AF447 case, you did repeatedly mention that the PNF wanted the PF to go back down, didn’t you ?

Having the classic yoke, it would have been obvious to that PNF that the PF was applying the opposite input to what was needed.

Sidestick is a sure way to waste valuable information in a multi crew operation.

We also have Birgenair though, when there was a disagreement between the Captain and FO, the FO could see what the Captain was doing but did not intervene. The yoke argument is a red herring, and the sooner Boeing bite the bullet and dispense with the ugly, archaic things, the better.

:E ;)

Doze. Birgenair is the red herring, as it is re: CRM, not Yoke/SS.

CONFiture has it down, and for me, it cannot be seen another way.

If memory serves, AF F/Os are not permitted to fly from a seat from which they do not ordinarily stick. If true, and I am not at all sure it is, this brings up yet another brick in the CRM outhouse. It also, if true, makes the A330 (functionally) a single position, single pilot aircraft, w/o a declaration of emergency twixt the pilots?

IF PNF could only drive the machine from LHS after emergency switch, yet another reason to support his apparent unwillingness to acquire command?

It seems clear, at least, that it may have kept him from taking over, along with the other obstacles he faced.

What say you?

One cannot roundly condemn either the pilots or the a/c alone. I will admit, after all this time, that some serious pilotage issues present.

[quote=Lyman]One cannot roundly condemn either the pilots or the a/c alone. I will admit, after all this time, that some serious pilotage issues present.[\quote]

Agreed, but we musn't allow the serious pilotage issue to cover the serious ergo and other issues.

What "ergo" issues? The yoke would not have fixed things - connecting the sidesticks would not have fixed things - this is a case of a temporary loss of airspeed data leading to panic, confusion and a crash. Nothing more, nothing less. There is nothing to suggest that the PNF would have been more inclined to take over had his stick been moving, and a lot to suggest that the barrier was psychological in nature, being uncertain as to the limits of his authority. He didn't intervene because he was afraid of a writeup if the Captain decides that the PF is correct and that he overstepped his bounds as PNF.

CONF, Lyman, jcj and others are trying to hammer the facts to fit the decision that they have already made, that Airbus must be found entirely at fault no matter what and that the hideous old yokes are safer (tell that to Captain Loft of EAL401).

DOZE. Hammer, meet Sledge. No one said the SS caused the crash, yet you imply some one has? What is your fear? How can you miss the obvious, yet you accuse others of "Red Herrings" but you are the one smelling of fish?

When Captain suggests "Pull" to the Pilot Flying, why did he do that?

BECAUSE HE DOES NOT SEE THE PF'S STICK AT FULL BACK.

"But I have been pulling for some time now!" says PF, in response.

Give it up.

Do you have a reference for that one?

With your above statement you do exactly the thing, you accuse others.

Welcome in your world.

The exchange, as translated into English is at approx. 2:14:05

The captain could see that the aircraft was pitching up via the instruments - no need to look at the stick. At this point, despite apparently verbally handing control over at 2:13:45, the PF is still pulling back on the stick, leading to the "DUAL INPUT" notification.

This is not a response to Lyman, as he is on my "soft ignore" list, this is for general information as to what was actually said on the CVR as opposed to what those with an agenda wish was said.

@Franzl - I accuse nobody, they're all pretty open about what they believe.

@ Mr. Wannabe
Hey, Mr. Wannabe,
Would you like an assessment from a dispassionate observer? I thought you would. Before this sub-thread gets nasty (or is it too late?), it needs to be said that there are few here who subscribe to a single agenda in assigning fault. Only a nincompoop would find this to be a one-cause accident.

It is crystal clear that:
1. Piloting was sub-par
1A. Therefore, training was insufficient
2. CRM was even worse than that
3. AB interface could be better in the interest of being, uh, "fool-proof"
4. Conditions for hand-flying were less than optimum.

Can't everyone participating in this latest, stupid argument agree on these points??? None of them are mutually exclusive. :=

@Organfreak - totally.

I just get (IMO rightly) irritated when I see the whole yokes vs. sidesticks, active vs. passive feedback being brought back up when it has pretty much bu*ger-all to do with the incident at hand. The fact is that active feedback and honking great control yokes have their drawbacks too - but you don't tend to hear that as often.

There is no such thing as a perfect interface, for flying or any other mechanical activity for that matter - *that's* something that needs to be accepted by all sides.

But DW,
I would argue that, though perfection is unattainable, all engineering and all art strives to get as close to perfection as possible. "It's good enough" isn't good enough in the case of airliner design, IMO.

If the side-stick or yolk could have been seen by the other pilots, there would have been perhaps a better chance that somebody would have figured out what was wrong. Not to say that's what caused the crash. I dunno about you, but when I get on an airliner, I'm hoping that I have every possible chance to live through the experience.

Not sure why you (apparently) see no room for improvement in the AB interface. Not meaning to challenge you.

"the FO could see what the Captain was doing"

This is key sentence.
He knew what AP, then PF, were doing. He was not in the dark, he KNEW, thanks to the obvious yoke displacement - This is one possible fewer hole in the cheese – Regrettably, he did not take advantage of that piece of first choice information – As Lyman wrote, CRM must be another possible hole in the cheese we have to look for.

Sidestick is a sure way to waste valuable information in a multi crew operation.
Where such statement is erroneous Dozy ?
Please comment …

Not the first time you’re advised Dozy, do not accuse if you’re not ready to provide the quotes.

Dozy

Your quote:

In all probability, this was directed at me. I don't have a position relative to yoke verses side stick. I may have, if the auto folks decide to replace the steering wheel with a side stick.

What has EAL401 got to do with anything? You want to keep the yoke verses the side stick going? Keep stiring the pot like you have been doing.

Dozy asks about ergo issues. Maybe ergo wasn't the correct term, but I'm speaking of a cluttered flight instrument display, tapes instead of dials for speed/altitude/vertical speed, attention demanding ECAM system, single sense (visual) input, no control feedback, ,,,,, have I missed any? Please notice that some of those are not Airbus specific.

Someone mentioned that the SS does offer feel. Yes, it does offer feel, but not feedback. Maybe I'm just "ham handed", but the feel offered by the Airbus SS is of little value to me. Once you break out of center, I don't feel much difference between part and full deflection. But more importantly, the FBW system prevents me from feeling the controls I.e. "feedback". In an MD80, I can feel a wing start to drop (thru the yoke) before it happens. In the Airbus, I have to see the wing drop on the ADI, make a corrective control movement, watch the ADI again to verify the control was successful. IOW, with feedback, I never had to think or process a control input. My hands felt the controls and sent the message straight to flying part of my brain which returned the correct input to the control yoke. No cognitive process involved.

Use it. Or lose it. The word is TACTILE. Yet another channel squandered at the altar of some goofy wonk.

From the BEA preliminary report N°3
Concerning Airbus plane .. it's what I find ...

3 - CONCLUSIONS
3.1 New Findings

° There was an inconsistency between the speeds measured, likely following the blockage of the Pitot probes in an ice crystal environment,
° The airplane’s angle of attack is not directly displayed to the pilots
° By design, when the measured speed values are lower than 60 kt, the 3 angle of attack values become invalid
° The engines functioned normally and always responded to the crew’s inputs


4 - SAFETY RECOMMENDATIONS

Angle of Attack Measurement

° The crew never formally identified the stall situation. Information on angle of attack is not
directly accessible to pilots. The angle of attack in cruise is close to the stall warning trigger
angle of attack in a law other than normal law. Under these conditions, manual handling can
bring the airplane to high angles of attack such as those encountered during the event. It is
essential in order to ensure flight safety to reduce the angle of attack when a stall is
imminent. Only a direct readout of the angle of attack could enable crews to rapidly identify
the aerodynamic situation of the airplane and take the actions that may be required.
Consequently, the BEA recommends:
that EASA and the FAA evaluate the relevance of requiring the presence of an
angle of attack indicator directly accessible to pilots on board airplanes.

My conclusions
Nothing wrong with the Airbus plane
Only one remark about angle of attack not displayed to the pilot ( not special .. as many modern airliners don't have this indication)

Special:
No recommendations (any) about the pitot tubes (nothing to change in the certification .. etc ..) or any recommendation to avoid to fly out of the certification range of pitot tubes
Note that all the chain of AF447 event begin cause the pitot tubes where not able to function correctly during a gap of time due to their usage out of the certification range
So the BEA accepts this situation and therefore also agrees that this event happens again with the risks that entails

Since it comes with no references attached, other than claims of anonymous posters on anonymous forum, it is as true as:

I am prepared to stand corrected If you find some good argument to support it. "I think", "I believe", "Someone said" are not good arguments.

There is a stick like mine in position mirrored by mine in the cockpit. Its function is identical to mine. Its position relative to the armrest indicates the input applied by my counterpart. It is not visible to me, but I can read its inputs as the a/c maneuvers. Like mine, it too is shaped like a Llama.

Wait.

Airbus, not being ignorant, was aware that the position of the stick prevented its observation by the opposite pilot. This means they think such visibility is unnecessary.

I am anonymous, and this is an anonymous thread. So the foregoing statement is not relevant to stick visibility.

True? or False.

TTex600, I could be wrong, but what I think you are perceiving is the time lag in your perceive-act cycle. An aircraft like the MD-80, you see the slightest of movement and you apply the slightest of pressure automatically and the wings stay level. If you have to perceive a bit of movement, and mentally process it, before making a correction on the 'Bus, then the response is going to be a bit delayed.

One of the early visual flight simulators for the A-4 Skyhawk had a bit of lag in the visual display of about 0.3 seconds. No problem to fly it 'visually' as long as the control movements and rates were small. But if the rates were high enough, the lag caused a disconcerting overshoot and could generate a PIO, normally in the roll axis. This may be an analog to what the PF on AF447 experienced in Alt 2 law with the higher than accustomed roll rate.

If I refer to the (all) preliminary reports or the note of the BEA concerning AF447 .. this nothing about this supposedly SS problems .. nor in recommendations or conclusion.
So .. officially (BEA) .. the SS system had nothing to do with AF447 case.
Remind that BEA (the experts) analyse the accidents and release conclusions and recommendations for improve safety when necessary.
So it seems that the discussion about SS is moot