F.A.O.: 3WE

[3WE]

I like your bike-cart, etc.

Thanks! Just doing my part to keep fossil fuels available so flyboy can live our dream.

I also wanted to acknowledge that you are correct we tend to limit trees to dicotyledonous species, and exclude grasses…except when we debate it…

[Not_Karl]

BBie farewells the good obsol'ete 747. Not_Karlie anxiously waits for Kentie's input.

[Not_Karl]

"4 engines 4 long haul" - BBie, paraphrased.

[Not_Karl]

It is said that Threewee is an expert in the field of extrapolation.

"4 engines 4 long haul" - BBie, paraphrased.

We should explain him that twice the engines = twice the chances of failure.

[Gabriel]

We should explain him that twice the engines = twice the chances of failure.

1 dice, 1/6 chance to get an ace.
10 dice, 10/6 chance to get an ace.

[3WE]

We should explain him that twice the engines = twice the chances of failure.

1 dice, 1/6 chance to get an ace, pm average..
10 dice, 10/6 chance to get an ace, on average.

Fixed.

[Gabriel]

We should explain him that twice the engines = twice the chances of failure.

1 dice, 1/6 chance to get an ace, pm average..
10 dice, 10/6 chance to get an ace, on average.

Fixed.

Not.

The 1st one is correct: Chance (probability) is 1/6, not "1/6 on average". You can say that on average you would get one ace every 6 trials, but not that the probability or chance is is 1/6 on average. The probability is 1/6 in every single trial (whether it ends up materializing or not).

The second one is of course incorrect. A probability is by definition a number between 0 and 1 so it can never be 10/6.
The probability to get 1 or more aces in 10 dice is 100% minus the probability of not getting an ace in any of the 10 attempts, so it is 1 - (5/6)^10 or about 84%.
Saying that the probability to get a given value in at least one out of 10 dice is 10 times the probability of getting such outcome in one dice is wrong. As wrong as saying "twice the engines = twice the chances of failure"

But for a small individual probability and a small number of individuals, it is almost the same, in the same way that simple or compound interest is almost the same for low interest rates and a small number of periods. For example, if the probability of one individual engine failing in 1%, the probability of at least 1 engine failure with 2 engines is not 2% but 1-0.99^2=1.99%

[3WE]

The second one is of course incorrect.

Somewhat disconcur…

For larger n of 10-dice rolls, you will get approximately 1.67 singles for a sample of 10

And two engines doubles the chance of engine failures…say we have French composite engines with a 50% failure rate when the plastic exhaust turbine melts.

Yes, the probability of at least one engine failure is 75%, but the probability of two failures is 25%… you’ll be losing an average of one engine per flight.

Acknowledged, I’m twisting your original post a little

[Not_Karl]

1 dice, 1/6 chance to get an ace.
10 dice, 10/6 chance to get an ace.

Concur.

As wrong as saying "twice the engines = twice the chances of failure"

Wrong.

For larger n of 10-dice rolls, you will get approximately 1.67 singles for a sample of 10

And two engines doubles the chance of engine failures…say we have French composite engines with a 50% failure rate when the plastic exhaust turbine melts.

Yes, the probability of at least one engine failure is 75%, but the probability of two failures is 25%… you’ll be losing an average of one engine per flight.

CONCUR. Think of all the cheap-composite-crackerbox blades added with each additional engine. And I forgot to add to my calculations the probability of a failing/falling engine damaging/knocking-out the other engine of the same side, so chances of two engines failing in a 747 are WAY higher than on a 777. Moreso, the chances of more than two engines failing are infinitely superior on the 747. But we know that Verbie pays large sums in snow coffee to Gabie to defend his crappy obsolete relicliners in interwebz forums...
Transoceanic flights should only be made in gliders.

Oh, and twice the engines = twice the consumption of fossil fuels and/or greenwashed, non renewable tree juice.

[Gabriel]

Oh, and twice the engines = twice the consumption of fossil fuels and/or greenwashed, non renewable tree juice.

This one is equally correct compared to other one that is equally wrong

[Not_Karl]

Oh, and twice the engines = twice the consumption of fossil fuels and/or greenwashed, non renewable tree juice.

This one is equally correct.

Indeed. Also twice the drag, weight, maintenance costs, and chances of reverser failure, pilots shutting down the wrong engine, asymetrical thrust, Not_reducing thrust after touch-down and FOD (including meteor impact).
Surely Threewee will be sensible enough to agree.

[3WE]

Surely Three wee will be sensible enough to agree.

Indeed.

I still want to fly one before you ban them or they are grounded by a SOCCER-loving, eurotrash conspiracy from the Airbus Union…and to show Bobby I can land the thing, including rudder use, even though I am lacking is a lot of procedural knowledge.

[3WE]

I know that you and Evan give me the “don’t feed the troll” treatment, but I put a heartfelt agreement post there, on AirFrance 2.0, and would be curious if you concur, or have other thoughts.

[Gabriel]

I know that you and Evan give me the “don’t feed the troll” treatment, but I put a heartfelt agreement post there, on AirFrance 2.0, and would be curious if you concur, or have other thoughts.

I think that I am more or less mid-ground between you and Evan.
Procedures, specific training and discipline are important.
"How to not_stall a Cessna 172" still works in an A380 (in alternate law).

[3WE]

I know that you and Evan give me the “don’t feed the troll” treatment, but I put a heartfelt agreement post there, on AirFrance 2.0, and would be curious if you concur, or have other thoughts.

I think that I am more or less mid-ground between you and Evan.
Procedures, specific training and discipline are important.
"How to not_stall a Cessna 172" still works in an A380 (in alternate law).

Don’t go black and white on what I think, Evan. I’m sure the Airbus procedures were well written. I’m also sure they weren’t followed.

Light a cigarette is an analogy, not a procedure. Conversely, if you have 10 warnings and are briefly vapor locked, keep flying the plane and proceed carefully…

Do you agree with my contention that Bonin and his buddy must have passed a somewhat decent screening and training and TECHNICALLY belonged there? I agree with you that they apparently didn’t belong there…but they must have passed everything to be flying an A-300 and not a Q-400.

Do you agree that perhaps their brains were likely full of procedural mush, but apparently lacking in some Uber basic stuff?

[Gabriel]

I know that you and Evan give me the “don’t feed the troll” treatment, but I put a heartfelt agreement post there, on AirFrance 2.0, and would be curious if you concur, or have other thoughts.

I think that I am more or less mid-ground between you and Evan.
Procedures, specific training and discipline are important.
"How to not_stall a Cessna 172" still works in an A380 (in alternate law).

Don’t go black and white on what I think, Evan. I’m sure the Airbus procedures were well written. I’m also sure they weren’t followed.

Light a cigarette is an analogy, not a procedure. Conversely, if you have 10 warnings and are briefly vapor locked, keep flying the plane and proceed carefully…

Do you agree with my contention that Bonin and his buddy must have passed a somewhat decent screening and training and TECHNICALLY belonged there? I agree with you that they apparently didn’t belong there…but they must have passed everything to be flying an A-300 and not a Q-400.

Do you agree that perhaps their brains were likely full of procedural mush, but apparently lacking in some Uber basic stuff?

More or less.

Whether they were properly trained (which I don't think I agree they were) and rated is not the same as belonging there, at leas in the sense I was using that term. Your "technically" is acknowledged. But that was you, not me.
How does a person react in a sudden very high stress situation is, I think, not fully forecastable. And that is critical to whether a person really (not technically) belongs there or not.

Do I belong there? (in the left seat of a Tomahawk, assuming that I was current and had a valid medical)
I want to believe that yes, but I am not 100% sure.

I can tell you that one time I had a total non-event which I thought may be an undetermined emergency and I acted (or reacted) in a way that I don't feel proud of at all. Even when I was in severe VFR, I unintentionally and unnoticedly banked, turned, deviated from the VOR radial I was following, and pitched significantly down increasing my airspeed quite a bit and leaving my cleared altitude. It took me several seconds to get my bearings together and tell myself what the F* are you doing? Why don't you start by FLYING THE F*ING plane? Which totally re-focused me and from there I managed it well. I want to think that I learned from that. But did I? The only way to tell would be having another real (or imaginary but believed to be real) emergency.

As for these AF pilots, the PF either focused just in roll not being able to pay attention even to pitch with is presented in the same artificial horizon as roll, or he pitched up intentionally. That is NOT following a procedure. In my opinion it is not even flying the plane.

The PM also did not follow any procedure. He limited himself to read stuff from the ECAM and utter some insufficient and ambiguous commands to the PF which were not followed (not sufficiently at least) and failed to call ANY procedure or take over to take care of the "fly the plane" part.

But.... when the EASA investigated other 13 UAS incidents, they found that in 0 of them the UAS memory items or subsequent procedure were followed. The UAS procedure itself was ambiguous, at least the Airbus wording.

But in any case, If a crew that is unable to use common sense rough P+P=P to keep the plane more or less stable, and does rather the opposite, I don't trust them with being able to follow any specific procedure.

The same goes for the other guy in the Q-400 that passed everything to be in the Q-400 but not in the A330.

The problem is that I don't think that there is any absolute solution to that. Sure, training and exposure in simulated environments helps, but is no guarantee of a rational reaction when it happens for real.

Long ago I proposed that pilots should be exposed in the sim to all kind of crazy stuff not in the procedures. Even if it is not expected that they would survive. The idea being to get them exposed to unexpected stuff and try to train their amygdala (in fact to train their front lobes to keep their amygdala in check). Of course I was immediately dismissed by those who know.

[elaw]

As for these AF pilots, the PF either focused just in roll not being able to pay attention even to pitch with is presented in the same artificial horizon as roll, or he pitched up intentionally. That is NOT following a procedure. In my opinion it is not even flying the plane.

Now this is where the shrink in me (and I claim I'm as good a shrink as any IT guy) disagrees.

Keep in mind when people panic*, the brain goes into "simplify everything" Neanderthal mode. So now let's take this procedure:
"If the plane is diving out of control, firewall the throttles and pull back relentlessly, unless the aircraft is in a control law other than normal in which case fly it like a 172."

...and run it through our paniicked*-Neanderthal-brain filter (insert beeps and boops here) and let's look at what comes out:
"If the plane is diving out of control, firewall the throttles and pull back relentlessly."

Oops.

* /fatigued/at a circadian low/etc.

[Gabriel]

From the cognitive perspective, I agree. There are ways to train the brain to act more rationally and less impulsively when under high stress. But I don't think they are applied in full in pilot training and, even then, they are no guarantee.

From a plane design perspective, I think it is even worse.

As I mentioned before more than once, I disagree with Airbus's decision to design, and EASA and FAA decision to accept, an alternate control law where the pitch response is still normal law (either stick-to-pitch rate or stick-to-load factor) which has no feedback vs angle of attack, while keeping autotrim active and removing all low energy and AoA protections (except for the stall warning). As a minimum, I think that the pitch response would revert to stick-to-AoA (so it requires increasing amounts of stick deflection to keep increasing the AoA, and neutralizing the stick would reduce the AoA rather than hold it or even keep increasing it to maintain the pitch or load factor of 1 with a deteriorating airspeed). By the way, that stick-to-AoA response is what occurs in normal law when you enter the low speed / high AoA protection regime (or something like that, although I am confident that flyboy will tell me that I am wrong without telling what is right).

Normal law response doesn't meet the certification requirements for handling properties. I imagine that Airbus demonstrated an at least equivalent level of safety thanks to the protections. So keeping this response when the protection are gone is, in my opinion, not a good idea. And yes, I am nobody and neither Airbus nor EASA nor the FAA cares crap about what I think. But this nobody still has an opinion.

[ocelot]

There was that incident recently where the FO became functionally incapacited for several minutes... I can't remember anything else about it so I can't at the moment find it... other than it involved messing with the flaps and/or gear without apparently realizing what they were doing... anyway, that sort of thing can happen but when it does, you ultimately aren't flying the plane.

Though that's not the same as "not flying the plane" in the sense of "not doing their job".

IME there are two separable effects when an emergency hits: one is shock and the other is "OMG I can't deal with this I don't know what to do". Shock/surprise may keep you from responding immediately, but it's the latter effect that causes people to shut down at length, all the more so if they think they ought to know what to do and ought to be able to deal. Training (or even planning) helps a lot... for some people.

In the military they say that you can never really tell how people are going to react when they're actually shot at until it happens -- I think the conclusion from that is that there are people with a "this is real, it matters" response that isn't readily engaged even by realistic exercises. So then when a real emergency happens, they're doing it for the first time.

[3WE]

There was that incident recently where the FO became functionally incapacited for several minutes...

Here is said thread (and what I find interesting is that it's BOTH crewmembers who are task saturated and performing maybe a bit off of perfection)

https://airdisaster.info/10/viewtopic.php?f=6&t=8283

I've been locked out of my account for several days and just now tried logging in.

I've been wanting to say (directed towards Eric a bit) (and this is a repeat), I think of Renslow different than Bonin: Ok, both freaked out at a warning (and maybe were woken from a brief doze off)...and Gabriel will cite Renslow's pull up as pretty damn aggressive and "long lasting", but I still contrast 2000 feet vs 35,000 feet and contrast 20 seconds vs. 3 minutes and what that means for you to get you [poop] together and go back to flying...

I can see myself (maybe, but not likely) pulling a Renslow, but cannot see myself pulling a Bonin.

The other bit of psychology: is a hidden fear that the plane is going to kill you.

I WONDER if Bonin feared HAL going nuts and killing him...HAL certainly went nuts.

I WONDER if Renslow feared falling out of the sky from a Roselawn stall (yeah, he STILL reacted wrong, BUT, as we have said, there's that weird tail stall phenomenon.

In the incident that Ocelot mentioned, The FO seemed to really lose his mind (the weather wasn't that challenging, but a MAProcedure can be quick and complicated). But the actions of the Captain...I may have NO business saying it, but I felt he should have been more on top of everything.

I can't get you guys to ever agree with me, but I think SOME pilots become SO FOCUSED on REGURGITATING procedures that they get in the cockpit by ADEPTLY barfing out the procedure, and the examiner then passes them as sharp. As they cram all this good stuff in their brains, the 172 lessons fade. STALL-FULL POWER-`20 DEGREES ANU... UAS THIS, ELCAS THAT, DUAL INPUT 3, ALTITUDE ALERT, NO AIRSPEED...AIRSPEED ITS TURNING UNCONTROLLABLY..(Each one of those has it's own procedure you regurgitate and there's procedures on which procedures get run first....

Through all of that, the human mind forgets that going straight ahead, FDNH WITHOUT A RELENTLESS PULL UP is called for.

PS: Renslow's situation called for VERY QUICK POWER UP, AND SOME CRITICAL PITCH INPUTS SINCE HE DID NOT_have much altitude to screw with.

Cue Boeing Bobby's dead horse GIF

[Gabriel]

I've been wanting to say (directed towards Eric a bit) (and this is a repeat), I think of Renslow different than Bonin: Ok, both freaked out at a warning (and maybe were woken from a brief doze off)...and Gabriel will cite Renslow's pull up as pretty damn aggressive and "long lasting", but I still contrast 2000 feet vs 35,000 feet and contrast 20 seconds vs. 3 minutes and what that means for you to get you [poop] together and go back to flying...

I can see myself (maybe, but not likely) pulling a Renslow, but cannot see myself pulling a Bonin.

Have you heard of a vicious cycle (or self-reinfocing negative loop)?
While startle is a thing and it make take a FEW seconds to start to get your bearings together, 20 seconds of irrational panic-driven reaction is hardly going to get any better in the next 3 minutes. Rather the opposite.

I WONDER if Bonin feared HAL going nuts and killing him...HAL certainly went nuts.

Whel, yeah, I suppose that doing mostly nothing is a way of going nuts...

PS: Renslow's situation called for VERY QUICK POWER UP, AND SOME CRITICAL PITCH INPUTS SINCE HE DID NOT_have much altitude to screw with.

Maybe he thought that, but the situation didn't call for that at all, and he should not have thought it did. Very much as Bonin in this regard, doing absolutely nothing for a while would have been a much better reaction than what he did.
2000ft is an order of magnitude more than what you need to recover from a stall warning, both with the old and the new procedure. He had a lot of time to do nothing or to be extremely slow and cautious in his recovery. When the stall warning sounds and the AP disconnects, the plane is not going to stall unless you actively pull up (or unless you fly through a mciroburst/windshear like in the incident I mentioned before). Because the plane was slowing down (so it had insufficient power set to maintain energy) and the AP, that had been acting so as to lose energy ion the form of speed, was now disconnected, the plane left at its own, being inherently stable in AoA and speed, would have simply pitched down by itself to a very benign glide where the energy is lost in the form of altitude, while holding the AoA and airspeed constant (+/- phugoid). By doing absolutely nothing, the ground was not seconds away but minutes away.

[3WE]

It’s only indirectly evident, but I never realized that the Pinnacle dudes stalled the crap out of their CRJ.

I forget the pitch, but I think a wing fell off to a 40-degree bank…

I give them credit for an ok recovery, and still wonder where Bonin’s head was.

Footnote: I was aware that the CRJ stalled enough to phugoid the engine intake of air* and cause flameouts, but I hadn’t imagined them falling and wallowing in the beginnings of a possible spin.

Footnote footnote: Intake of air = a process, vs Air Intake = a structure… El español puede variar.

[Gabriel]

Stickshaker activation, stick-pusher activation which they overrode by brute force, stalling the crap pout of there and busy calling ATC to request a descent....

It was pretty clownesque.

[ocelot]

I can see myself (maybe, but not likely) pulling a Renslow, but cannot see myself pulling a Bonin.

They are still not really the same thing. Whatever mental state Bonin was or wasn't in, he was processing enough to be able to say "I've been pulling up the whole time". Whereas in the other case the guy was just completely spaced.

Now I can't remember exactly why I brought that up in this context. Something about various levels of "not flying the plane".

I can't get you guys to ever agree with me, but I think SOME pilots become SO FOCUSED on REGURGITATING procedures that they get in the cockpit by ADEPTLY barfing out the procedure, and the examiner then passes them as sharp. As they cram all this good stuff in their brains, the 172 lessons fade.

I'm not sure why you think none of us agree with you. It's an obvious failure mode of training by procedure, and there are lots of people out there who would rather learn things by rote than understand them. And examples appear on AVH regularly.

I'm not convinced, however, that it applies to this accident.

[ocelot]

Also, I'm slightly amused that this is the headline thread in the Off-Topic Forum and it's on topic.