Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.


View this topic in a long page with up to 500 replies per page Create new topic
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | ... | 54
Technofreak
6657 posts

Uber Geek
+1 received by user: 3477

Trusted

  #1006108 15-Mar-2014 12:24
Send private message

joker97: if they knew there was a decompression they should

1) take a big breath and hold for as long as possible .....

don't you reckon?


No. Why?

You are missing the point.  Normal depressurisation procedure is to don the O2 masks and breathe normally. They wouldn't know there was no O2 supply in this case.

The depressurisation will cause the air in the lungs to be expelled rapidly, besides taking a big breathe of nothing (well nearly nothing and certainly no where enough O2) isn't going to stop you from losing consciousness very rapidly.




Sony Xperia XA2 running Sailfish OS. https://sailfishos.org The true independent open source mobile OS 
Samsung Galaxy Tab S6
Dell Inspiron 14z i5




Batman
Mad Scientist
30014 posts

Uber Geek
+1 received by user: 6217

Trusted
Lifetime subscriber

  #1006112 15-Mar-2014 12:35
Send private message

so the breath has been taken for you by the decompression - hold it.

descend.

do whatever else need to be done.

you seem to suggest they should do everything else and by the time they think about descending they're unconscious. I reckon you should remain conscious by descending asap, then do whatever else.

maybe I have no idea about commercial jetliners

mattwnz
20520 posts

Uber Geek
+1 received by user: 4798


  #1006116 15-Mar-2014 12:54
Send private message

They are essentially now looking for an object the size of a stapler, in an area the size of the north island, due to the probability that it flew for 4 hours after it's last known location. If it crashed at sea, then the odds are that a lot of it has now sunk, making it even more difficult. I think the best way would be aerial photos taken shortly after the disappearance, unless they can pock up a signal from the blackbox. It really does make you wonder why the technology for monitoring location is so poor in todays world, when you can locate a lost iPhone with ease.



Sideface
9652 posts

Uber Geek
+1 received by user: 15607

Trusted
DR
Lifetime subscriber

  #1006133 15-Mar-2014 13:02
Send private message

mattwnz: ... It really does make you wonder why the technology for monitoring location is so poor in todays world, when you can locate a lost iPhone with ease.


... when the iPhone is on dry land at sea level.




Sideface


Technofreak
6657 posts

Uber Geek
+1 received by user: 3477

Trusted

  #1006135 15-Mar-2014 13:05
Send private message

joker97: so the breath has been taken for you by the decompression - hold it.

descend.

do whatever else need to be done.

you seem to suggest they should do everything else and by the time they think about descending they're unconscious. I reckon you should remain conscious by descending asap, then do whatever else.

maybe I have no idea about commercial jetliners


Have you actually understood what I have posted?

You say "So the breathe has been taken for you by the decompression - hold it"  

NO, NO NO, the decompression has expelled the air from your lungs, you have breathed out, there is nothing to hold.  You will need to breathe in again, only now the air is so thin it doesn't have enough O2 pressure for consciousness.

Also did you read what I said about time of useful consciousness and how it is dramatically reduced with a rapid depressurisation? They would have have about 15 to 30 seconds to have donned the masks and initiate emergency procedures.  

If it was a rapid depressurisation with a loss of O2 it would have been all over in about 30 seconds.




Sony Xperia XA2 running Sailfish OS. https://sailfishos.org The true independent open source mobile OS 
Samsung Galaxy Tab S6
Dell Inspiron 14z i5


Technofreak
6657 posts

Uber Geek
+1 received by user: 3477

Trusted

  #1006136 15-Mar-2014 13:08
Send private message

Sideface:
mattwnz: ... It really does make you wonder why the technology for monitoring location is so poor in todays world, when you can locate a lost iPhone with ease.


... when the iPhone is on dry land at sea level.


.... and that phone has access to the internet.  It's not the GPS that broadcasts the position, the GPS just works out the phones position and then this data is sent out by the app via the internet




Sony Xperia XA2 running Sailfish OS. https://sailfishos.org The true independent open source mobile OS 
Samsung Galaxy Tab S6
Dell Inspiron 14z i5


 
 
 

Shop now at Mighty Ape (affiliate link).
tdgeek
30048 posts

Uber Geek
+1 received by user: 9455

Trusted
Lifetime subscriber

  #1006174 15-Mar-2014 13:36
Send private message

The key is no debris. If it broke up at altitude there would be a huge amount of floating debris, if it hit the water at speed, the same. If they landed in the water, it would probably break up and take in some water and could well sink in one piece with minimal debris.

Taking into account the wind and current and the huge level of searching they would have found debris. And if the plane did attempt a water landing they would have had enough control to mayday. A real mystery.

Technofreak
6657 posts

Uber Geek
+1 received by user: 3477

Trusted

  #1006177 15-Mar-2014 13:46
Send private message

tdgeek: The key is no debris. If it broke up at altitude there would be a huge amount of floating debris, if it hit the water at speed, the same. If they landed in the water, it would probably break up and take in some water and could well sink in one piece with minimal debris.

Taking into account the wind and current and the huge level of searching they would have found debris. And if the plane did attempt a water landing they would have had enough control to mayday. A real mystery.


Assuming the searching has taken place in the right area.

There's a fair amount of speculation that the aircraft was airborne or at least intact for up to 5 hours after it "went missing"




Sony Xperia XA2 running Sailfish OS. https://sailfishos.org The true independent open source mobile OS 
Samsung Galaxy Tab S6
Dell Inspiron 14z i5


tdgeek
30048 posts

Uber Geek
+1 received by user: 9455

Trusted
Lifetime subscriber

  #1006181 15-Mar-2014 13:47
Send private message

Technofreak:
tdgeek: The key is no debris. If it broke up at altitude there would be a huge amount of floating debris, if it hit the water at speed, the same. If they landed in the water, it would probably break up and take in some water and could well sink in one piece with minimal debris.

Taking into account the wind and current and the huge level of searching they would have found debris. And if the plane did attempt a water landing they would have had enough control to mayday. A real mystery.


Assuming the searching has taken place in the right area.

There's a fair amount of speculation that the aircraft was airborne or at least intact for up to 5 hours after it "went missing"


I agree, it must be elsewhere, and if so, and if no comms, seems to indicate a planned intervention, hijacking or pilot suicide

mattwnz
20520 posts

Uber Geek
+1 received by user: 4798


  #1006187 15-Mar-2014 14:01
Send private message

Sideface:
mattwnz: ... It really does make you wonder why the technology for monitoring location is so poor in todays world, when you can locate a lost iPhone with ease.


... when the iPhone is on dry land at sea level.


Yes, but with an iPhone you are talking about a device worth a few hundred, which relies on cell sites on land, With a plane, they are hundreds of millions, and they have access to satellite communications for location, rather than just land based radar stations, when in range . The fact that allegedly Boeing was able to monitor pings from the engines for 4 hours after it went missing, but the airline didn't subscribe to that monitoring service shows that more monitoring was possible.  I think  someone has made a massive error, and I think it does indicate foul play, related to something that someone has done intentionally. I Wold be a fantastic story, and great movie, if the plane was found to have landed somewhere, on some small island. Reminds me a bit of the 'lost' TV show.

Sideface
9652 posts

Uber Geek
+1 received by user: 15607

Trusted
DR
Lifetime subscriber

  #1006192 15-Mar-2014 14:13
Send private message

mattwnz: ... I Wold be a fantastic story, and great movie, if the plane was found to have landed somewhere, on some small island. ...


The Boeing 777-300, at Maximum Landing Weight, needs a runway that is 8,100 ft long.




Sideface


 
 
 

Shop now at Mighty Ape (affiliate link).
Fred99
13684 posts

Uber Geek
+1 received by user: 10018


  #1006202 15-Mar-2014 14:26
Send private message

Sideface:
mattwnz: ... I Wold be a fantastic story, and great movie, if the plane was found to have landed somewhere, on some small island. ...


The Boeing 777-300, at Maximum Landing Weight, needs a runway that is 8,100 ft long.


What do you reckon the chances are of a successful ditching of a 777 at sea?
It can and has been achieved with smaller jet aircraft - in emergency situations where the pilots have had to contend with loss of engine power - with a need to act with urgency.
If the plane was hijacked or with the rogue pilot scenario, whoever was at the controls seemed to know what to do for the best chance to evade detection.
Carefully planned and executed, my guess (and only a guess) would be that a skilled pilot might have been able to ditch the plane with all passengers surviving.




mattwnz
20520 posts

Uber Geek
+1 received by user: 4798


  #1006207 15-Mar-2014 14:32
Send private message

Sideface:
mattwnz: ... I Wold be a fantastic story, and great movie, if the plane was found to have landed somewhere, on some small island. ...


The Boeing 777-300, at Maximum Landing Weight, needs a runway that is 8,100 ft long.


Certainly difficult, but if it was planned, they would have planned somewhere to land it, maybe the desert. maybe they tried landing at sea close to land, but probably not easy to do without it breaking up. Although they did do this with that plane in New York.

tdgeek
30048 posts

Uber Geek
+1 received by user: 9455

Trusted
Lifetime subscriber

  #1006208 15-Mar-2014 14:32
Send private message

Fred99:
Sideface:
mattwnz: ... I Wold be a fantastic story, and great movie, if the plane was found to have landed somewhere, on some small island. ...


The Boeing 777-300, at Maximum Landing Weight, needs a runway that is 8,100 ft long.


What do you reckon the chances are of a successful ditching of a 777 at sea?
It can and has been achieved with smaller jet aircraft - in emergency situations where the pilots have had to contend with loss of engine power - with a need to act with urgency.




The jet landed in New York ok and years ago a hijacked plane landed in the shallows at an island but the wing caught the sea and it broke up, many survived . Very do able

Sideface
9652 posts

Uber Geek
+1 received by user: 15607

Trusted
DR
Lifetime subscriber

  #1006218 15-Mar-2014 14:35
Send private message

Fred99: What do you reckon the chances are of a successful ditching of a 777 at sea? ...

See: http://www.askcaptainlim.com/ditching-flying-81/389-can-a-boeing-777-ditch-safely.html

"A Boeing 777 is designed to be capable of ditching safely on the water and stay afloat. That is why there are 8 slide rafts in the aircraft capable of accommodating more than 300 passengers in the event of a safe ditching on the sea.
How long will the B777 stay afloat on the water will depends on many factors. Firstly, there must not be substantial damage on the aircraft body to cause massive leaks. Secondly, the ditching must be properly executed (it is possible to do so) and the impact with the water surface must be reduced sufficiently to that of a normal landing profile. The sea condition must also be reasonably smooth.
According to Boeing, if the Boeing 777 ditching is properly handled with an optimum center of gravity and normal gross weight, the airplane should come to a rest slightly nose high on the water. The forward doors should be about four and a half feet and the aft doors be about two and a half feet above the water. At high gross weight, the aft doors may be less that two feet.
After ditching, an undamaged Boeing777 will stay afloat for a fairly long time - something like a drifting boat on the sea ..."

All this assumes that the crew are in control at the time of landing.




Sideface


1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | ... | 54
View this topic in a long page with up to 500 replies per page Create new topic








Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.



Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.