Air India Crash
- Thread starter Grim5
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Soldato
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Skipped update 4 but 5 is out and seems to indicte RAT deployed and that the landing gear has started to retract
There is no way of proving or disproving the RAT deployment. I wish people would stop fixating on this, adamant that it was definitely deployed (or indeed wasn't)
The videos are poor quality and the audio may be indicative, but it may equally be a nearby Air con unit, poor quality microphone artifacts or anything else.
The videos are poor quality and the audio may be indicative, but it may equally be a nearby Air con unit, poor quality microphone artifacts or anything else.
Associate
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The lack of engine noise when they should be at take-off thrust would need addressing too.
That's what I said before like almost two days ago - RAT was deployed which indicates major system failure
Yes but you can hear it, the rat makes a very descriptive sound that can clearly be heard in the earliest footage. Personally I've never heard any aircon unit motor that sounds like that
But anyway speculation is boring at this stage; they found the black box which will tell them everything
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I'd never heard of a ram air turbine before this incident, from an engineering point of view it's genius, and is one of those things that makes me wonder why I never knew of its existence, or thought of it at all. Makes perfect sense.
I do wonder about the efficiency of it, if the aircraft is flying with the wind it'll be a lot less powerful than against the wind, but that'll be factored in to its design.
I do wonder about the efficiency of it, if the aircraft is flying with the wind it'll be a lot less powerful than against the wind, but that'll be factored in to its design.
Soldato
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Definitely a unique case given the 787 hasn't had a fatal crash yet and the potential of a double engine failure (being a very rare situation). Hopefully the flight data recorder will reveal answers to this...
APU restart is now at the top of the list thanks to Sully; get some sort of power. So pressing APU as its all going to wrong would put the doors open as it tried to spin up to start.
Remember, it was 23 seconds was rotation to impact. Also the airfield is at 200 feet above sea level and the quoted altitude was also above sea level.
Remember, it was 23 seconds was rotation to impact. Also the airfield is at 200 feet above sea level and the quoted altitude was also above sea level.
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It will produce the same power for any given *airspeed*. The effect of steady wind on an aircraft in flight is only relevant to its movement with respect to the ground.
No mate, just no. The ground speed and the air speed are two very different things, before factoring in things like ambient temperature, air density, velocity, etc.
APU start on elec loss is automatic on the 787, they wouldn't have even had to press anything.
It's already been stated about how wind direction means nothing, but as for the RAT itself, they're always of a constant-speed variety, meaning their blades can change pitch to maintain the correct speed over a wide range of airspeeds.
This includes the low speed we see in the case of this crash, and indeed the blades would have been at a very broad pitch to maintain speed, leading to the very distinctive noise heard in the video that is being baffling dismissed by many.
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Caporegime
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You mean the blades pitch to maintain the correct angle of attack
. The CSU maintains the RPM (Speed).
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Stop nitpicking, it was meant to be a broad overviewYou mean the blades pitch to maintain the correct angle of attack
Soldato
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Fascinating video.
Not being an expert in this sort of stuff, I can't see how it could be "natural" dual engine failure. I start to wonder if it was a deliberate act that took out the hydraulics and or electrical systems - especially considering what's been going on around that geographical area. A loud bang followed by flickering lights. Sounds to me that they lost systems, and at that height couldn't recover. Also a tad suspicious that it happened just at that moment in time when it was most likely to crash the plane.
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Just for the sake of clarity, killing all the electrics or all the hydraulics would not kill the engines. They have a self-driven generator to ensure electronic control of them continues even in the event of a catastrophic failure of the electronics - to the point where even the trust lever position detector is actually powered by this self-driven generator. Continued running of the engines is absolute.
There's an excellent post on PPRuNe which covers in a bit more detail about how various things operate, and appears to be written by a chap who was previously responsible in certifying aircraft types. It concludes as follows:
As speculated by a few including myself, and it seems more and more are coming round to the same area of conclusion, it's looking most likely to be a catastrophic software failure or pilot suicide.
Soldato
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How about this one
Pilots forget to raise landing gear and nearly run out of fuel
The Airbus A320, with 99 passengers on board, took off from Kolkata, bound for Mumbai, but with the wheels affecting the aerodynamics it burned excessive quantities of fuel.