Go Back  PPRuNe Forums > Flight Deck Forums > Rumours & News
Reload this Page >

Malaysian Airlines MH370 contact lost

Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

Malaysian Airlines MH370 contact lost

Old 27th Jun 2014, 11:55
  #11181 (permalink)  
 
Join Date: Mar 2002
Location: Moved beyond
Posts: 1,170
Received 83 Likes on 48 Posts
AndiKunzi:

The RAT on the 777 can't power all the aircraft systems. It only supplies power to a few essential systems, such as the Capt and FO flight instruments and the flight control power supply assemblies. The autopilot is not considered essential and is not powered by the RAT.

As stated on p33 of the ATSB report, the assumption is that one engine flamed out first, followed by the second, resulting in a loss of power to both AC busses. At that point, the flight control system would have reverted to a degraded mode, the autopilot would have disengaged and 'if there were no control inputs then it would be expected that eventually a spiral descent would develop'.

When operating in a degraded mode, the flight control system has no envelope protection, i.e. no stall, overspeed, overbank protections, etc.

Last edited by BuzzBox; 27th Jun 2014 at 12:37.
BuzzBox is offline  
Old 27th Jun 2014, 12:44
  #11182 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
the passage of the satellite through the eclipse.
- can you explain (simply, please! - or offer a link) what an eclipse is in this context?
BOAC is offline  
Old 27th Jun 2014, 14:18
  #11183 (permalink)  
 
Join Date: Jul 2009
Location: USA
Age: 74
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
what will we learn from finding MH370?

Let's say the next search is successful and for some n million $ we get a look at the wreckage and even retrieve the black boxes.

With the (reasonable) scenario most lately discussed we aren't going to find an intact airplane, but rather a whole bunch of bits widely scattered, except a lot of them will be held together by wiring etc. No hope of recovering bodies at this point, at least not for autopsy.

While it is possible the CVR might have comments made in the last hour, but even that seems unlikely. FDR will tell you it ran out of fuel, when, and maybe some info on the descent, but nothing about WHY unless it captured some sort of failure, but this airplane appears to have been mechanically fine.

So what if anything is gained by finding the bits, except perhaps a sense of finishing the job?
MrDuck is offline  
Old 27th Jun 2014, 14:35
  #11184 (permalink)  
 
Join Date: May 2004
Location: Bear Island
Posts: 598
Likes: 0
Received 0 Likes on 0 Posts
Devil strange question

"So what if anything is gained by finding the bits, except perhaps a sense of finishing the job?"

the probable cause and any associated safety implications for the manufacturer and worldwide operators of the B777 and other aircraft types perhaps ?
Teddy Robinson is offline  
Old 27th Jun 2014, 14:36
  #11185 (permalink)  
 
Join Date: Apr 2014
Location: Australia
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
anyone have info if they have searched northern part of the arc south of Indonesia?
Not sure, but what I do believe is that the US military have the airborne drone technology to conduct arial drone searches quickly. Thus they could have been checking out near all of the suspect areas for surface debris fairly promptly. With a Global Hawk RQ-4A or RQ-4A BAMS drone. They have high resolution cameras, approx. 1 metre resolution capable. They can search 40,000 square miles ( 200 x 200 miles ) in 24 hours.
HeyIts007 is offline  
Old 27th Jun 2014, 14:57
  #11186 (permalink)  
 
Join Date: Oct 2012
Location: Australia
Posts: 85
Likes: 0
Received 0 Likes on 0 Posts
MrDuck - could be lots of things. Has the onboard oxygen supply been used? Are there fire-damaged panels? Evidence of a struggle in the cockpit, or that people have tried to force the cockpit door? If the plane was uncontrollable but the passengers were still alive, we might find video on phones, last letters, etc.

The CVR and FDR may well contain meaningful data too; for example they should cover whether or not there were control inputs during the descent (which could be the difference between everyone being dead, the pilot(s) deliberately crashing, and the pilot(s) doing their best to achieve a water landing).

If/when they do find it, I suspect that they'll be able to get a pretty good idea of what happened.
Slatye is offline  
Old 27th Jun 2014, 15:05
  #11187 (permalink)  
 
Join Date: Oct 2007
Location: France
Posts: 136
Likes: 0
Received 0 Likes on 0 Posts
Eclipse: on page 23 (page 28 of the PDF) of the last report.
Around the equinox, all the satellite in "geostationary" orbit are for a time in the shadow of the Earth, and so have to run on batteries and have their temperature dropping which can induce a frequency drift even if the oscillator is in a special location (in the sat architecture) which try to maintain it constant.
Shadoko is offline  
Old 27th Jun 2014, 15:12
  #11188 (permalink)  
 
Join Date: Jul 2013
Location: uk
Posts: 180
Likes: 0
Received 0 Likes on 0 Posts
search area

correction; "priority" search area is 350km by 50km ie 17500 sq km.
presumably if aircraft is not found there the search will be extended.
portmanteau is offline  
Old 27th Jun 2014, 15:15
  #11189 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
Thanks Shadoko
BOAC is offline  
Old 27th Jun 2014, 22:31
  #11190 (permalink)  
 
Join Date: Dec 2006
Location: Florida and wherever my laptop is
Posts: 1,350
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Slatye
MrDuck - could be lots of things. Has the onboard oxygen supply been used? Are there fire-damaged panels? Evidence of a struggle in the cockpit, or that people have tried to force the cockpit door? If the plane was uncontrollable but the passengers were still alive, we might find video on phones, last letters, etc.

The CVR and FDR may well contain meaningful data too; for example they should cover whether or not there were control inputs during the descent (which could be the difference between everyone being dead, the pilot(s) deliberately crashing, and the pilot(s) doing their best to achieve a water landing).

If/when they do find it, I suspect that they'll be able to get a pretty good idea of what happened.
Precisely. I would expect:
  1. Quite a lot of information from pax cell phones - especially if panic broke out by the cockpit door.
  2. A full DFDR which would provide all the information necessary to find out what was done from SSR deselect.
  3. A useless CVR unless it was left selected and 'someone' was awake within 2 hours of ditching and talking.

All that information would be sufficient to identify root cause, and remove a lot of speculation. The root cause in turn would identify who if anyone would be the subject of litigation.

It is really important to find that airframe.
Ian W is offline  
Old 28th Jun 2014, 00:11
  #11191 (permalink)  
 
Join Date: May 2003
Location: USA
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Retrieving information

Good points about the potential to retrieve information from passengers cellphones, laptops, tablets, etc.

I am curious if any telecomms folks on the forum could comment on the likelihood of being able to retrieve such information after what is likely to be months underwater at great pressures. We all know that FDRs and CVRs are "hardened" in such a way as to enable this (e.g. AF447) but I imagine that commonly used memory in such consumer products might be considerably more fragile. Thoughts ?

averow is offline  
Old 28th Jun 2014, 00:21
  #11192 (permalink)  
 
Join Date: Jul 2009
Location: USA
Age: 74
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
that makes sense

Thanks Ian W. I get it now.
Like most everyone here I am semi-obsessed with this puzzle.

But surely there's an upper limit on costs.
We aren't close yet but I think it is clear that this could get really expensive.
There's not much economy of scale in a detailed search.
Some billions but not 100s of billions?
If we have to wait 5 years for an answer, doesn't the value decline?

It is a big ocean. I hope they find it early in the search.
MrDuck is offline  
Old 28th Jun 2014, 00:24
  #11193 (permalink)  
 
Join Date: Mar 2004
Location: Turks and Cacos
Posts: 323
Likes: 0
Received 0 Likes on 0 Posts
I can't believe every time I come here this thread is at the top of the forum with almost 20 Mil views.

Now listen. They are not going to find it and if they did any evidence would be useless after getting dragged up from 3 miles deep.

Jeez let it go and move on. Sometimes s*^t happens and you can't plan for events like these.

And if you think cell phones would have any useful info after being submerged in a saline solution at great depth for such a period you may have to go back to school for some more chemistry and physics classes.
On_The_Top_Bunk is offline  
Old 28th Jun 2014, 01:30
  #11194 (permalink)  
 
Join Date: Sep 2008
Location: Where it is comfortable...
Age: 60
Posts: 911
Received 13 Likes on 2 Posts
FDR

All that information would be sufficient to identify root cause, and remove a lot of speculation...
I think there is a pretty clear consensus that the track taken by the aircraft was the results of deliberate human inputs by someone familiar with the aircraft systems.

Now those on this forum who fall in this category will know precisely where to look for the CB which will render the quoted assumption invalid. I have already suggested (but was modded out) that the most likely scenario when/if wreckage found is that FDR recording stops at/about the same time the transponder was deactivated, and the FDR will contain 2 hours of silence.

Of course there is a slim chance that the FDR/CVR and possibly some other non-volatile memory from aircraft and passenger devices might yield some useful clues. Memory chips are enclosed in a fairly robust plastic casing, while the external contacts will corrode, the actual encased chip has a good chance of remaining undamaged. I know of several cases of lost / damaged underwater cameras retrieved with the sd card retaining the photos taken after a couple of years spent underwater.
andrasz is offline  
Old 28th Jun 2014, 02:59
  #11195 (permalink)  
 
Join Date: Dec 2009
Location: Alberta Canada
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
@on the top bunk
Recently a camera was recovered that had been submerged in the ocean for over a year and the memory card was readable.

If you are frustrated when you come here and see the number of views, then save yourself the irritation and don't. Your rant here isn't useful.
AlbertaGirl is offline  
Old 28th Jun 2014, 04:34
  #11196 (permalink)  
 
Join Date: Mar 2014
Location: Maine USA
Age: 82
Posts: 199
Likes: 0
Received 0 Likes on 0 Posts
I am curious if any telecomms folks on the forum could comment on the likelihood of being able to retrieve such information after what is likely to be months underwater at great pressures. We all know that FDRs and CVRs are "hardened" in such a way as to enable this (e.g. AF447) but I imagine that commonly used memory in such consumer products might be considerably more fragile. Thoughts ?

I don't know for sure, but keep in mind that integrated circuits are basically sophisticated rocks, and probably pretty sturdy.
PersonFromPorlock is offline  
Old 28th Jun 2014, 07:58
  #11197 (permalink)  
 
Join Date: Apr 2010
Location: London
Posts: 7,072
Likes: 0
Received 0 Likes on 0 Posts
"I think there is a pretty clear consensus that the track taken by the aircraft was the results of deliberate human inputs by someone familiar with the aircraft systems."

BBC

"The Australian authorities have laid out much of the analysis, and their reasons to go with the new search area, in a 64-page report.


While no-one yet can presume they know what happened on MH370, it is clear from reading this document that investigators are working on the idea that the crew was unconscious for the larger part of the flight. Everything we know about MH370, and everything we've learned from previous accidents, would seem to point to the jet ending its flight after having spent a long time on autopilot."
Heathrow Harry is offline  
Old 28th Jun 2014, 08:11
  #11198 (permalink)  
 
Join Date: Apr 2009
Location: Oakland, CA
Age: 72
Posts: 427
Likes: 0
Received 0 Likes on 0 Posts
it is clear from reading this document that investigators are working on the idea that the crew was unconscious
No, it isn't clear at all.
Being on autopilot says absolutely nothing about the state of the crew. A perfectly alert crew would also spend most of this trip on autopilot.
Also the document clearly states in bold type some of the assumptions were only made for the purpose of assisting in the search and may have nothing to do with the actual causes of the accident (page 35). They emphasize they are not accident investigation committee and shouldn't be confused with one.

Last edited by olasek; 28th Jun 2014 at 08:30.
olasek is offline  
Old 28th Jun 2014, 10:02
  #11199 (permalink)  
 
Join Date: Dec 2006
Location: Florida and wherever my laptop is
Posts: 1,350
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by On_The_Top_Bunk
And if you think cell phones would have any useful info after being submerged in a saline solution at great depth for such a period you may have to go back to school for some more chemistry and physics classes.
SD cards and similar solid state storage are close on impossible to erase/destroy apart from being burnt. Data has even been recovered from SD cards that have had nails driven through them.

The electronics of the phone will die almost immediately on immersion but the solid state phone memory not at all. (A warning for all those who discard bricked cellphones one of the first things techies do on receiving such a phone is check and read the solid state memory and old SD cards, and run undelete to see if there is anything 'interesting')
Ian W is offline  
Old 28th Jun 2014, 12:56
  #11200 (permalink)  
 
Join Date: Jun 2000
Location: Australia
Posts: 4,188
Likes: 0
Received 14 Likes on 5 Posts
FDR will tell you it ran out of fuel, when, and maybe some info on the descent, but nothing about WHY unless it captured some sort of failure,
'

Remember the Silk Air MI 185 Boeing 737 suicide crash? The investigation found that the two cockpit FDR circuit breakers had been pulled just prior the aircraft being pushed over into its dive. That meant no info after that was available to investigators. The CVR circuit breaker had also been pulled a few minutes earlier which is why the only CVR info that was available was the period before the CB were actuated by someone. If someone in the 777 went to the trouble of switching off the transponder and ACARS, chances are the same person may have tried to hide more vital information by disabling the CVR and FDR by some means (circuit breakers in the 777?)
Centaurus is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.