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-   -   Pax sue Boeing in DBX crash (https://www.pprune.org/rumours-news/598438-pax-sue-boeing-dbx-crash.html)

Ian W 29th Aug 2017 11:14


Originally Posted by sptraveller (Post 9875717)
They hit the ground at 125 knots.

I never claimed the crew didn't fail. The crew failed. Did I mention that the crew failed?

For the avoidance of doubt, the crew failed. Is three times enough?

I take issue with ascribing zero blame to the automatics.

The automation silently refused a command for thrust with airspeed above 125 knots without weight on all the wheels.

Instead of describing why the crew effed up (they did, that's four times), can anyone describe why the automatics were perfectly correct?

The automatics did precisely what they were designed to do nothing more nothing less. As such they were perfectly correct.

As you have said multiple times the crew failed to confirm power was actually increasing.

What you are really saying is 'can anyone describe why the automatics were designed like that?'.

That question should be followed with:

'Why is it necessary to have a button that does just what a competent crew could do with a straight arm and maintenance of control of the aircraft during a go around?'

then

'Why is it necessary to ensure that the button does not cause the engines to go to full throttle on the ground as a competent crew would not press buttons inadvertently?'

I put it to you that both of these questions are answered by 'the designers believed that they had to design the TOGA button for less than competent crews'.

What they failed to check for was the competency required to know the limits of the TOGA button.

Of course the design could have been that the RAAS operation automatically initiates TOGA regardless of weight on wheels. The automatics retract undercarriage once the aircraft is climbing with climb power then raise the flaps at the correct speeds, then fly the circuit using the uplinked trajectory from the ATC automation then autoland and taxi to the gate. But there were some designers that thought the crew would be competent. :)

Capn Bloggs 29th Aug 2017 11:48

Lookout, UAV Ian has arrived! :)


Originally Posted by Ian W
I put it to you that both of these questions are answered by 'the designers believed that they had to design the TOGA button for less than competent crews'.

I hope you say that tongue-in-cheek. Obviously, with today's high performance engines, having a crew (PF then the PNF) mucking around trying to manually, accurately set a thrust (takeoff, GA or whatever) is silly. Hence a button that will do that (and in Boeings, incorporating at two-step thrust limit for GAs to help prevent gross overshoots, as has happened on Scarebusses). So as far as I can see, there is a useful purpose for TOGA buttons.

The issue here is only that it doesn't work in a Bolter situation. On other jets, it does. If you don't practice bolters regularly, then you're probably going to stuff one up if you have to do one, especially if, as in this case, you have plenty of IAS and things look OK on the ASI and therefore haul it back into the air. So much to do in so little time, with the aeroplane reacting, initially, as you would expect. And because you never handfly, you've lost that seat-of-the-pants sinking feeling when the bottom starts to drop out of it with no thrust on. Throw in a distracting radio call and...

Oldaircrew 29th Aug 2017 12:27

Oldlurker,

I hear what you are trying to say.

However, the report is worded so that very little blame is placed on the shoulders of the operator and the manufacturer. While I believe the conditions changed in that instant, the company culture is such that the captain felt he had to go around or be called in for a safety debrief(possibly not his first, which would have made his decision making much harder) and therefore went around even though the landing could be completed safely.

The strict adherence to SOPs(with little common sense being allowed) instilled by this operator, placed this crew in an untenable and unenviable position.

I also find it amusing that we have a system in place(RAAS) to prevent us going off the end of the runway but which uses the beginning of the runway as a reference.

Ian W 29th Aug 2017 14:48


Originally Posted by Capn Bloggs (Post 9876140)
Lookout, UAV Ian has arrived! :)


I hope you say that tongue-in-cheek. Obviously, with today's high performance engines, having a crew (PF then the PNF) mucking around trying to manually, accurately set a thrust (takeoff, GA or whatever) is silly. Hence a button that will do that (and in Boeings, incorporating at two-step thrust limit for GAs to help prevent gross overshoots, as has happened on Scarebusses). So as far as I can see, there is a useful purpose for TOGA buttons.

The issue here is only that it doesn't work in a Bolter situation. On other jets, it does. If you don't practice bolters regularly, then you're probably going to stuff one up if you have to do one, especially if, as in this case, you have plenty of IAS and things look OK on the ASI and therefore haul it back into the air. So much to do in so little time, with the aeroplane reacting, initially, as you would expect. And because you never handfly, you've lost that seat-of-the-pants sinking feeling when the bottom starts to drop out of it with no thrust on. Throw in a distracting radio call and...

Yes of course it was somewhat tongue in cheek - though it is as you suggest "If you don't practice bolters regularly, then you're probably going to stuff one up if you have to do one," So the TOGA button is put in and someone says ahh but what happens if.... and they put in a simple WOW switch to stop an embarrassing taxiing incident. But the crew either didn't know about that inhibition and/or failed to check the power. It would have been better if the designers had used weight on nose wheel.

Sailvi767 29th Aug 2017 17:06

There is a lot of strange stuff being posted here. Love the two handed comments. When you hit the ToGA buttons on the 777 the nose pitches up nicely on the 777 with little yoke pressure needed. In any case as you are hitting the TOGA buttons you push the throttles up anyway. It's a natural motion with how the buttons are placed. If you need two hands to fly the plane you need some gym time!

cessnapete 29th Aug 2017 20:10

Im amazed at the stuff being written here by pilots re hands on controls. Surely every pilot from Cessna150 to B777 etc is taught to fly with one hand on the control column/yoke /stick and one hand on the power management control/s from before the flare, to touchdown/go around. Especially in aircraft with automatics, to cover the failure, mismanagement of said automatics.
Its simple pilot stuff, or airmanship, which seems to be disappearing in some airline SOPS.
Not being sexist, but even my mates slim lightweight daughter can fly a B744 with one hand, normal SOP in her Big Airline.
Not having flown with it, but a system which says 'long landing'' mandating a a crew to perform a go around (botched) with 9000ft plus runway remaining, defies logic.

Vessbot 29th Aug 2017 21:00

What are you amazed by? I didn't see anyone advocating to land with both hands on the yoke. Nor to go around starting with both hands on the yoke. In fact, the general consensus is that this was the cause of the crash.

pilot9249 29th Aug 2017 23:38


Originally Posted by GICASI2 (Post 9876067)
Because: the captain failed to apply thrust; the FO failed to ensure the thrust levers advanced to a GA thrust level as indicated on the EICAS; the captain rotated to the GA attitude before the FO called rotate (which he didn't) at Vref (and with no thrust, I doubt Vref was ever achieved); NEITHER noticed and called a negative speed trend; the FO allowed himself to become distracted at a critical time (!) and unquestioningly raised the gear lever on command. Lots of failures and a perfectly serviceable jet was destroyed.

You have described in graphic detail how many ways the crew failed. It's surely almost unimaginable that any crew could catalogue this absurd collection of failures. It's ridiculous. Unbelievable. WTF?

But it happened.

Let me pose a question.

If when pressing TOGA the automatics had enunciated "TOGA. Ignored.", would the outcome most likely have been harmed or improved?

Is there any way that this could possibly have made things worse?

galaxy flyer 30th Aug 2017 00:09

I wouldn't see any harm in message being posted like "TOGA DISARMED" or your example. But, if they missed the throttles not moving; I suspect they'd miss the more subtle EICAS message.

How does the Airbus system work in a similar situation? I know the pilot has to retard the throttles out of some detent prior to touchdown.

galaxy flyer 30th Aug 2017 01:56

I would think the rather large throttles NOT moving would be a more than adequate signal that pressing TOGA didn't work! That's the point of moving throttles--tactile signaling of thrust position. Most pilots can readily identify thrust by merely feeling the throttle position. Heck, years of formation flying and I can hear the thrust from the sound of the engines.

H Peacock 30th Aug 2017 07:59

If you want to start adding EICAS messages etc then why not go the whole hog and put the TOGA button under your right thumb on the yoke - you wouldn't ever have to let go of it and reach for the pesky throttles!

The more this thread goes on I can see some whacky lawyer successfully arguing to a bewildered jury that this was all Boeing's fault and not down to the crew/airline simply not prioritising the 'aviating' aspect of their operation.

HPSOV L 30th Aug 2017 08:58

Why not have the TOGA switch make a 'BZZZT!' sound when pushed after the Boeing autothrottle system has inhibited itself with one of it's famous 'indirect mode changes'?
Or how about when it's in Hold on approach below 1000'?

Not manly enough? Tell that to the passengers involved in a crash after the humans up front make one of their periodic cock ups. Personally I think attitudes to improvements in safety still have a long way to go.

It's a bit of a stretch to sue Boeing who designed the best system they could with the technology available at the time. But that doesn't mean it can't be improved with the benefit of experience.

Doors to Automatic 30th Aug 2017 09:57

Apologies if this has been asked before but according to the official accident report the aircraft touched down approximately 3600 feet (1100m) past the threshold of 12L. Whilst long, by my calculations this would still leave around 8,200 feet of runway ahead. This would be around twice as far as the aicraft needs to stop with firm braking on a dry runway and indeed more than Gatwick, Manchester, Newcastle and Birmingham have available after the correct touchdown point. So why go-around in the first place?

H Peacock 30th Aug 2017 11:08


So why go-around in the first place?
RAAS activated due to the perceived long landing! It didn't understand that there was ample runway remaining, the crew simply (tried) to follow the RAAS command!!

Snyggapa 30th Aug 2017 11:11


Originally Posted by HPSOV L (Post 9876991)
Why not have the TOGA switch make a 'BZZZT!' sound when pushed after the Boeing autothrottle system has inhibited itself with one of it's famous 'indirect mode changes'?

The universally accepted sound to be used in this situation is the "Family Fortunes ECK-UUUUUURRRRR" noise

https://www.youtube.com/watch?v=7XMW6Z_Oq38

Could also use it on "gear up without positive rate of climb"

galaxy flyer 30th Aug 2017 11:30


Originally Posted by H Peacock (Post 9877129)
RAAS activated due to the perceived long landing! It didn't understand that there was ample runway remaining, the crew simply (tried) to follow the RAAS command!!

And, where they went from pilots to bring pax with a forward view.

GICASI2 30th Aug 2017 11:51


Originally Posted by galaxy flyer (Post 9876750)
I wouldn't see any harm in message being posted like "TOGA DISARMED" or your example. But, if they missed the throttles not moving; I suspect they'd miss the more subtle EICAS message.

How does the Airbus system work in a similar situation? I know the pilot has to retard the throttles out of some detent prior to touchdown.

As has been said before, on the BUS, TOGA is selected by pushing the thrust levers to the fully forward detent. And this system was (reluctantly) designed by an engineer! However, it works and this accident would not have occurred on an AIRBUS (never say never in aviation!!!)

Capn Bloggs 30th Aug 2017 12:01

Almost...

Jetstar makes changes after go-around mishap | Australian Aviation

glofish 30th Aug 2017 12:19


In any case as you are hitting the TOGA buttons you push the throttles up anyway. It's a natural motion with how the buttons are placed.
I must assume that you have never touched a T7.

The TOGA switches are on the front side of the levers. They are actually very easy to push in the idle position, but quite twitchy when the levers are pushed up, you need a awkward wrist torsion to really push them. So nowhere near to a natural motion. It is actually almost easy to push them in the retarded/idle position and then "assume" that TOGA is selected. Especially the former Airbus pilots tend to not follow the lever movement, thus not feeling alarmed if they do not move (btw one of the many reasons i propagate to leave AB ab initio trained pilots on AB and vice versa).

The Airbus system by positioning/clicking the motionless lever to the TOGA position has its advantage here. Although it has its own trap, namely the non movement can lead you to assume that the system has not switched and not increased power, even though you checked the FMA. You need to confirm by looking at the N1 indicator and in stunned moments this is not easy. Asseline got trapped by that and re-clicked, therefore delayed the spin-up -> result known.

The best TOGA system is on the good old MD11. It has a palm switch that can hardly be pressed in the retard/idle position. You basically must shove up the levers to be able to push the switch with your palm, so you can hardly forget the shoving up.

(BTW it also had a very handy last resort or brain fart switch: A spring loaded bar at the firewall position. Push through it and gives you at any time AP/AT off, full available thrust, wings level and max climb on the FD. Very handy for botched landings at any rad alt, wind-shear or GPWS)

underfire 30th Aug 2017 12:56


Bounce the ac, press TOGA and pulls back with both hands....see where that gets you.
I sincerely hope you are not suggesting that "pull" means a good old yank, because as you would know being a rated pilot, all that is needed is a gentle control input to achieve the required result.
I am certain everyone understands what happens when you pull vs pull too hard. How is pulling too hard suggested? Aside from that, read in the context of the response, it was meant to show the difference between a balked, and a balked with touchdown.
Sensing weight on wheels initiates a cascade of variables, and simply pressing TOGA may not solve your problem.
That is why I wondered what the poster was talking about by stating they had trained all of the pilots to balked, especially balked with touchdown. What is the standard or criteria?
Just so you are aware, the RNP procedures are coded to include missed, so we do the balked and balked with touchdown to see how the automation and coding work together, and to make certain in these conditions, that the ac stays withing the specified containment area.

About 2 hands, that is simply a preference, but about the explanation on TOGA being same as takeoff, steering may be better, but once you rotate, 2 fingers works it, even on the 748.
I really not sure why you minimize the experience of some of these drivers, they are the chiefs from QANTAS, ANZ, United...and the manufacturers.

I will run the balked with touchdown scenario in detail, but with all of the emphasis on training new drivers, sim time is virtually impossible these days.


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