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-   -   Malaysian Airlines MH370 contact lost (https://www.pprune.org/rumours-news/535538-malaysian-airlines-mh370-contact-lost.html)

LASJayhawk 9th Mar 2014 20:11

Is it within the realm of possibility to have severe clear air turbulence, combined with a structural issue with the repaired wing, and it just flat broke?

Dumbo Jet 9th Mar 2014 20:26

MH370 may have turned back
 
Malaysia’s air force chief, Rodzali Daud, said radar indicated that the plane may have turned back, but did not give further details on which direction it went or how far it veered off course. (Source: National Post)

Air force chief Rodzali Daud said the investigation was now focusing on a recording of radar signals that showed there was a "possibility" the aircraft had turned back from its flight path. (Source: bbc.co.uk)

Is it not possible that an inflight disintegration may cause what seems to be a significant course change on a set of radar signals, due to parts of the aircraft falling in different directions?

I posted this question earlier - but no replies - was it really that dumb a question? I'm sure I've seen even less informed! Would appreciate a reply even a 'don't be daft Dumbo Jumbo!'

tubby linton 9th Mar 2014 20:31

My initial thought when I heard of this accident was of Lauda Air 004 which had an in-flight deployment of a thrust reverser almost twenty three ago. The initial speculation was that it was a bomb. I hope that the recorders are found soon and that the speculation comes to an end.

barrel_owl 9th Mar 2014 20:36

ACARS
 
@1a sound asleep

The most useful piece of evidence is possibly the ACARS DATA. Why have we seen nothing of the ACARS info

For those that dont know what ACARS is - (ACARS) is a digital datalink system for transmission of short, relatively simple messages between aircraft and ground stations via radio or satellite.
Unfortunately I am unable to provide you a link, however it has been reported here and other forums that the Malaysian Civil Aviation General confirmed during a press conference that no ACARS message linking to malfunctions of the aircraft were sent to Malaysia Airlines Operations Centre.

It is unclear whether the ACARS downlink transmission suddenly stopped, as I am led to conclude based on this report, or not. MA and Malaysia authorities are being pretty tight lipped so far.

Based on this sparse information, I conclude that the ACARS downlink feed from the aircraft completely stopped at some point, which is consistent with the sudden disappearance of the aircraft at 35,000 feet right after changing its track from 25° to 40°.

As incredible as it may seem, after more than 48 hours the only valuable information we have so far come from flightradar24. Unfortunately, FR24 has no coverage below 30,000 over the ocean.

Sven Sixtoo 9th Mar 2014 20:46

Having finally got to the end of the thread, another bit of data of dubious relevance.

I was part of the crew of one of the recovery helicopters at Lockerbie. The debris trail was 70 miles long, and notwithstanding that we knew where to start, bits were obvious all along it. I'm fairly sure that even crossing it at right angles, we would have picked it up in about one leg in three of a creeping line search. I've done a lot of searches over water, and looking for sunken ships that were actually sunk more-or-less where someone thought did tend to reveal debris fairly quickly.

So, if the search is anywhere near the right place, I would expect an in-flight disintegration at altitude to lead to discovery of wreckage / debris in fairly short order.

MLHeliwrench 9th Mar 2014 20:48

Comms breakers
 
What if someone (pilots or terrorists) pulled the comms breakers? In an area with poor or no primary radar coverage, the area of possible landing/crashing/ditching is quite large.

3db 9th Mar 2014 20:52

Coagie,
I just looked up 40kHz in the Radio Regs, it is allocated to fixed maritime mobile - they would not be putting a distress beacon in that band without guard channels. Also, a google search reveals a circuit diagram which has a loudspeaker symbol as the "final bit" and not an aerial symbol, so my apologies, you are correct. Must google before posting for things I am not familiar with!

WillowRun 6-3 9th Mar 2014 20:55

Your Attention, Please
 
A Triple 7 is down. Or, presumably down. Maybe plausible is an air piracy and commandeering incident (after the World Trade Center, Pentagon and Shanksville PA, I decline to use the "h-j" word in this context). But if the plane landed safely someone - a lot of someones - are committed to some serious radio silence.

I start with the above modestly-pedestrian observation as a prelude to a sort of "point of order". The event is way, way high in profile (obviously) - meaning that lots of posters are drawn into the stream, not only because of the very significant Civil Aeronautics Authority-level of interest, and not only because of the intensifying SUSPENSE, but also because ... we like puzzles, mysteries. We just do.

And my point? I'm not justifying or clawing back at any one or any posts or certainly any Moderator. I'm advocating a modicum of restraint. If you are a wind-tunnel designing, computational dynamics and boundary layer equation semi-genius, and some guy posts something tongue in cheek, or wildly speculative, or a tad factually erroneous, or repetitive to prior posts, or otherwise unenlightened post, just shrug it off. This air crash ("if", see above) is likely to become quite historic. Let the thread flail and wail and hang-and-look over Wichita in a prototype YF-17 with 1974-era avionics, if it wants to do so.

And if you, on the other hand, are like me, a sub-sub to a wrench-turner's mate hard, hard below the conn aboard the Michigan, and have no idea how to recover from a spin, STHU [Shut The Hotel Up] (just jokin' about the USS Michigan part).

If it was a crash, may the airman's prayer to the Almighty, that the souls of the dead find peace, and more so the next of kin - be allowed some pace and place hereto, here too. Lord Wingspan Almighty, the Maker of All Lift, aeronautical, peace-loving... and at the bar (which is where yours truly usually ends up).

mm43 9th Mar 2014 21:03


I just looked up 40kHz in the Radio Regs, it is allocated to fixed maritime mobile
Please don't confuse the radio spectrum with the audio spectrum. In the context of the pingers, the frequency of 40kHz is ultra-sound.

Greek God 9th Mar 2014 21:10

Mid Air?
Unannounced / unidentified military activity is not unheard of in this area.
For an established proven commercial aircraft to completely disappear without any indication, points to some sort of catastrophic instantaneous failure/ breakup.
That would indicate explosive, structural or midair.
Beyond that we just cant say.
Some of the drivel spouted here would be quite humorous if the situation was not so tragic.
The media frenzy of speculation, theories and fantasy is thoroughly distasteful but sadly a reflection on humanity (or rather lack of it)
I'm sure all will out eventually.

Skipness One Echo 9th Mar 2014 21:16


A one tonne basketball and a normal basketball of same volume dropped in atmosphere won't hit the ground at the same time.
IF they're the same size and shape they abolutely will.

PhilGSolent 9th Mar 2014 21:19

It is definitely in the fishermans favour to collect anything they find, I read in the last couple of days about a previous crash where a fisherman found what he thought was a piece of plywood that turned out to be part of a tail from a similar crash in the 90s.

Boeing rewarded the fisherman by paying him $5250 for handing it in.

It was the Adam Air Flight 574 crash:-
The fisherman received a reward of 50 million rupiah (equivalent to about $5,500) for his discovery

http://en.wikipedia.org/wiki/Adam_Air_Flight_574

VH-Cheer Up 9th Mar 2014 21:23


Quote:
Quote:
Would not immigration officials at Schiphol receive a passenger manifest of the incoming flight, and check that manifest against a database of reported passport losses, and identify that individual for special attention on entry?
No they would not, there is no such requirement in Europe or anywhere else but the US.
But surely red lights would have flashed when those two passengers travelling on stolen showed up at the Schengen border at AMS - given that the passports produced to the immigration officer were registered as stolen with Interpol?
what makes you think they would present the same stolen passport on arrival at immigration? They may be carrying a dozen different, perhaps altered, passports.

Kev738 9th Mar 2014 21:24

Distance between low and high speed buffet at FL350 is depending on the weight mainly, it is difficult to determine this without additional information.

It seems to me it's a tougher job to stall a tripple 7 all the way down in to the sea as you have a big control column in front of you. This makes it easier for the guy next to you to recognize what control inputs you are actually making and maybe even correct you from doing wrong.

However, anything remains possible.

thcrozier 9th Mar 2014 21:29

Jack1985:


Please refer to Post 999 for a summary of what is known.

Lancair70 9th Mar 2014 21:48

So where are these pics of wreckage that some on here are commenting on? I've scoured the news sites and cant find anything but pics of what looks like coral spawn or algae bloom on the water.

flyingfox 9th Mar 2014 21:58

Australian ABC news reports are suggesting Malaysia is being very slow to release information about suspect passengers. In Western countries the mug shots of these passengers would be all over the media and investigative journalists would be hard on the case, regardless of the present state of knowledge. They seem to be reluctant to say anything which might point to deficiencies in their systems or open themselves up to litigation.
Apparently Malaysia doesn't compare passenger passports with current Interpol lists.

LASJayhawk 9th Mar 2014 22:01


Phiggsbroadband

Please excuse me if this has been posted earlier.. But I cannot help thinking that the transponder return cannot go from 35,000ft to 0ft in next to no time.
Even with the nose vertically down it would take 40+ seconds, and more if you take the maximum possible curve into account. Freefall from that altitude would take over 3 minutes, and would be speed limited by the terminal velocity.
The FR24 trace continues several miles beyond the 0ft point. So either someone switched the transponder off, or it had a partial progressive failure.
Short answer, it didn't.

Long answer, that 35k to 0 is someone's less than fantastic software. It you turned off altitude reporting you would get an invalid not zero. And transponders altitude encoding starts 1200 feet below sea level anyway.

So the best guess is someone's code interprets no data as 0 feet.

surfcat 9th Mar 2014 22:06

On the freefall time, the 3+ minute estimate is a bit off.

s=ut + 0.5at^2, assuming an initial vertical velocity of 0, and initial height s=8000m (I can't be bothered to convert 35,000' to m), t would be around 40s.

golfyankeesierra 9th Mar 2014 22:08


Unfortunately I am unable to provide you a link, however it has been reported here and other forums that the Malaysian Civil Aviation General confirmed during a press conference that no ACARS message linking to malfunctions of the aircraft were sent to Malaysia Airlines Operations Centre.

It is unclear whether the ACARS downlink transmission suddenly stopped, as I am led to conclude based on this report, or not. MA and Malaysia authorities are being pretty tight lipped so far.
To all those people placing high hopes on ACARS, you probably don't know what it is..

It is only the datalink itself, just the system delivering a message, it doesn't make the message.
Messages can be directed (amongst others) at ATC, the airlines operations control or the technical department and it can be used to access external providers, for instance to get wx reports.
It can be uplinked or downlinked an can be automatically or manually.

Now the messages from AF447 originated from the ACMS (look it up) that reacted on several active faults that it sensed. ACMS downlinked those faults automatically to AF's tech department as it is apparently programmed to do.
That works in my airline the same but these are usually customer options, so who knows how Malaysian has set that up or what system they have in place.

Anyway you cannot conclude anything from the absence of downlink reports.

And for the conspiracy theorists suspecting MAS to keep messages for themselves, in my company it is not allowed to sent any sensitive information (like Creditcard numbers of customers) because it is easily intercepted (Get your free ACARS decoder on the 'net).
Would be something if it turns out afterwards that MAS had withheld information.
Don't think so!


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