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Old 18th Mar 2014, 00:34   #5441 (permalink)
 
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Quote:
NO. The ping happens in real time. The aircraft was on that arc somewhere at 8:11 AM. There is no margin of error.
There is a margin of error on the final resting place for several reasons, the biggest being that there is no way to know how much fuel was left after the last ping. Sure the plane must have been very near that arc @ 8:11 but then there is up to 59 minutes more fuel to burn plus glide time.

Y'all might be talking about 2 different things. One thing is where the plane was @ 8:11 which is very near the arc. The other thing is the final resting place of the plane which could be hundreds of miles away from the arc...
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Old 18th Mar 2014, 00:37   #5442 (permalink)
 
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RifRaf3 said

Quote:
All the scenarios are far fetched, that's how accidents happen in an environment of high safety and redundancy. Yes, the fires would have to occur in that 'far-fetched' manner for this to occur. So what.
I'm interested in the least far-fetched scenario.
Regardless of how the fire would have to act, how is it ACARS never sends out a message saying the fire is there?

Edit to say, also see this great post from MountainBear (just in case you missed it before reading my question)

Malaysian Airlines MH370 contact lost

Last edited by D.S.; 18th Mar 2014 at 00:50.
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Old 18th Mar 2014, 00:38   #5443 (permalink)
 
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Quote:
Originally Posted by RifRaf3 View Post
Mountain bear
Your point is a valid one, but perhaps a little dogmatic. If it's correct that last ping was picked up by only one sat as opposed to two sats at 4 to 5 hrs giving intersection arcs, then fire gets less likely.
Those reasons, assuming the pings are reliable evidence, make a hijacking to a distant Nthn, or Sthn area the best scenario and that's just what the authorities seem to be opting for.
to the best of my knowledge no ping has been picked up from two satellites, where is the source for that?
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Old 18th Mar 2014, 00:41   #5444 (permalink)
 
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Picky picky picky.

The cost of the parts is not just what you pay to the supplier, but the qualifying and testing that has to be done to mil spec standards. I stand by my original statement.
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Old 18th Mar 2014, 00:41   #5445 (permalink)
 
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Quote:
Originally Posted by D.S. View Post
RifRaf3 said

Regardless of how the fire would have to act, how is it ACARS never sends out a message saying the fire is there?

Edit to say, also see this great post from MountainBear (just in case you selectively missed it before reading my question)

Malaysian Airlines MH370 contact lost
I have no idea what level of ACARS reporting Malaysian has but.....

ACARS is not all knowing. If there is un-annuciated fire, ACARS will not know about it and will not report it.

How could it?
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Old 18th Mar 2014, 00:43   #5446 (permalink)
 
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I see some comments about 1 v 2 satellites. When CNN started drawing two boxes a few days ago, I assumed they had reads from two satellites. Now that they've released the single arc picture, it makes sense why. Even if the plane was in range of two Inmarsat satellites, it doesn't mean both recorded the ping registration.

Think of that ping like your cell phone. Even if you hit 3 towers, the only one that will record your checkin is the one that holds your registration at that moment. It's very possible that, like your cell phone, the SATCOM decides which sat is the right sat to register with, and it will make that clear in it's ping. Then, the other one knows to disregard it.

Can't answer Q's right away since I'm driving.

I'm really curious as to why Inmarsat hasn't released the arcs for the other 5 pings. Couldn't hurt anything.
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Old 18th Mar 2014, 00:43   #5447 (permalink)
JPK
 
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Ornis:

Could you elaborate on what you said re the plane linking up to a satellite in the Perth area? You seem to be the only one with a sane (or sober) mind left? Thank you.
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Old 18th Mar 2014, 00:44   #5448 (permalink)
 
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The future of ELT and tracking

Quote:
Thinking of the future, what can be done about FDR/CVR? Maybe there should be several devices, synched, one fixed as at present and two ejected by force - compressed gas, spring, or a small pyrotechnic charge? The technology is off the shelf and has been for decades in 'cluster bomb' systems which survive incredibly high forces. One to my knowledge survives > 100,000g (sic). We cannot accept the present designs as fit for purpose.
Great question. it seems ludicrous to assume anything will wok perfectly in a crash, including ELT systems.

Firstly let me say I am not a pilot, however there are some common-sense options that we can all see, and have been suggested before.

I have been for a long time advocating a live video feed of the cockpit and tailcam video streaming to a remote black box - something like Skype . It can be done today. Many airlines host internet facilities.

Failing this we should have an on - all - the -time ELT tracking system - satellite based. When it stops, we know there is a problem, and any time the signal is lost it should be the subject of an immediate investigation and intercept by the closest air force.

Also, mandate the immediate notification of loss of online tracking of any aircraft to the relevant military and handover to military radar tracking for resolution.

Mandate the carrying on person of a satellite tracking device on the pilots and flight crew.

Many ideas, all been said before, it is upto the ariline industry to step up to the plate and start giving us passengers some assuarance that they can take better care of us.
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Old 18th Mar 2014, 00:50   #5449 (permalink)
 
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lakedude

Quote:
Y'all might be talking about 2 different things. One thing is where the plane was @ 8:11 which is very near the arc. The other thing is the final resting place of the plane which could be hundreds of miles away from the arc...
While I agree 100% with everything else you said, it needs to be pointed out Fuel Levels would indicate it likely touched down extremely close to the last ping. (if it were not already grounded)

The plane being in the air at 8:11 itself is already pushing what they would have been able to do (barring the extremely unlikely landing/refuel option, of course)
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Old 18th Mar 2014, 00:50   #5450 (permalink)
 
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nitpicker.

Your point 3, "under inflated wheels will not catch fire" is not quite true.
Research the DC8 fire in Jeddah in 1991 operted by a Canadian company,National? on behalf of Nigerian Airways.

Cause of fire and subsequent loss of aircraft, under inflated tyre(s).

Wunwing
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Old 18th Mar 2014, 00:51   #5451 (permalink)
 
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Re: Electronics bay

LD7, perhaps flip your question around and ask 'can you get out of the electronics bay in flight?'

Under the scenario that some third party had access to this area in order to shut down comms, who's to say they weren't occupying the avionics compartment prior to pax boarding?
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Old 18th Mar 2014, 00:53   #5452 (permalink)
 
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Quote:
Originally Posted by TelcoAg View Post
I see some comments about 1 v 2 satellites. When CNN started drawing two boxes a few days ago, I assumed they had reads from two satellites. Now that they've released the single arc picture, it makes sense why. Even if the plane was in range of two Inmarsat satellites, it doesn't mean both recorded the ping registration.

Think of that ping like your cell phone. Even if you hit 3 towers, the only one that will record your checkin is the one that holds your registration at that moment. It's very possible that, like your cell phone, the SATCOM decides which sat is the right sat to register with, and it will make that clear in it's ping. Then, the other one knows to disregard it.

Can't answer Q's right away since I'm driving.

I'm really curious as to why Inmarsat hasn't released the arcs for the other 5 pings. Couldn't hurt anything.
the inmarsat coverage data shows it could only ever have been picked up by one sat, except for possibly a tiny period around the time the incident started.

I doubt if the decision to release the data from the other earlier pings is now int he hands of inmarsat.
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Old 18th Mar 2014, 00:54   #5453 (permalink)
 
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Quote:
Originally Posted by ve3id View Post
Commercial chips are mostly designed and tested from 0 to 70 C. Industrial chips go to wider ranges, sometimes -40 to +105 C, sometimes more. Military/Aerospace spec are generally qualified from -55 to +125 C and are warehoused in a secure cage separately from commercial and industrial quality chips, with documentation attached to prove their having been tested. Complete systems are temperature cycled between the limits while cycling the power supply between its limits. I believe avionics uses mil/aerospace qual chips, therefore should not be a problem at -40. That's why avionics is so expensive.
On many biz jets, which do have the space for EE bays within the pressure vessel, the majority of the avionic boxes are located in compartments which are completely unheated and unpressurized in flight e.g. the Lear 45, in which the central avionics computer, air data computers, nav and com radios, transponders, attitude/heading computers etc. are all located in the nose, forward of the flight compartment. There is nothing between the avionics and the intense cold found at the flight levels but the thin metal skin of the two removable doors used to access the equipment on the ground.

A similar situation exists on a Hawker 800, where all sorts of avionics are crammed into a space in the upper portion of the nose gear wheel well. Again, this compartment is completely unheated and unpressurized, and is also exposed to wind blast and moisture anytime the nose gear is deployed.

The point being that the majority of commercial avionics systems are designed to operate perfectly well over a very broad range of environmental conditions, including prolonged exposure to extreme cold.
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Old 18th Mar 2014, 00:55   #5454 (permalink)
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Could any B777 drivers explain what the problems are with flying at FL45 with an aircraft configured and loaded as MH370 was?
Is it simply that you are much closer to coffin corner?
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Old 18th Mar 2014, 00:57   #5455 (permalink)
 
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Quote:
The KQ507 crash in Cameroun pretty much buried itself in mud and there was very little debris at ground level making discovery and recovery very difficult.
In mud, yes.

In very shallow water over mud, yes OK.

With 50 m or more of water over mud. Nope. The plane ail fragment if it hits the water at high speed. Some of these pieces will be small with little momentum. Some won't be very aerodynamic (? hydrodynamic). Can you see a detached aileron flying through this much water and digging itself into the mud.

Even a high velocity (supersonic) bullet will travel a short distance, rapidly decelerate due to deformity and tumbling, and then slowly sick to the bottom. A bullet has much greater density, (and therefore greater momentum relative to surface area) than a plane. But if you fired a bullet into mud, sure it will go below the surface.
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Old 18th Mar 2014, 00:59   #5456 (permalink)
 
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Inmarsat

Quote:
I'm really curious as to why Inmarsat hasn't released the arcs for the other 5 pings. Couldn't hurt anything.
Unless there's some Sekrit Skwirrel Blowing Snow going on preventing it, we'd all be a lot better off if Malaysia would turn this over formally to the NTSB. The incompetence is staggering.

That said, the previous ping plots won't be released until it's in someone's interest to do so. It's probably not Inmarsat's call.

But some people know where those pings were, and you can bet their surveillance satellites are burning some fuel to take a close look.
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Old 18th Mar 2014, 01:00   #5457 (permalink)
 
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I'm away from my PC, so can't back run the data, but did anyone consider the oil rig worker might have seen an iridium flare? Duration about right, but I'm not able to check the angles.

He seems a pretty savvy guy, so I doubt he is that easily fooled.
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Old 18th Mar 2014, 01:04   #5458 (permalink)
 
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Quote:
Is it simply that you are much closer to coffin corner?
You'd probably be close to at least one CC boundary at 1g. Not a 7777 pilot though...
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Old 18th Mar 2014, 01:06   #5459 (permalink)
 
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Lost in Saigon

Quote:
ACARS is not all knowing. If there is un-annuciated fire, ACARS will not know about it and will not report it.

How could it?
That's kind of the whole point of ACARS - to report issues. If a fire affected a single system somewhere, ACARS would have reported it.

See, for example, the 25 automatic messages sent from AF447's ACARS system during its 4 minutes of catastrophic issues
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Old 18th Mar 2014, 01:07   #5460 (permalink)
 
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Regarding under inflated tires, they can certainly cause a fire. I had a tire burst at v1 in a biz jet, which was duly aborted. But if the same tire is retracted, it becomes a ticking time bomb

Nigeria Airways Flight 2120 - Wikipedia, the free encyclopedia
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