AirAsia QZ8501 Missing
Discussion
djc206 said:
Starfighter said:
My understanding was that the captain requested a change of height but ATC said no as there was other traffic. If the captain and declared PAN or MAYDAY then ATC would make a gap by moving that other traffic.
Not quite. As an ATCO if someone asks for weather avoidance I immediately move the other traffic out of the way where possible (they may be unable to change course if they too are avoiding). I don't wait for a pan or mayday. That's just laziness and stupidity all rolled into one.Wasn't the last known altitude 36k ft? Either they had got the message, but didn't acknowledge it for some reason, or they had climbed before ATC gave the ok for 38k ft? Perhaps 36k wasn't high enough to avoid the bad weather, or the engines iced up during the climb?
mjb1 said:
Presumably though, you tell the first plane to hold steady whilst you shuffle others out of the way? Which is why why the ATC said 'no' initally. Two minutes later they had made a gap, but contact was lost by then.
Wasn't the last known altitude 36k ft? Either they had got the message, but didn't acknowledge it for some reason, or they had climbed before ATC gave the ok for 38k ft? Perhaps 36k wasn't high enough to avoid the bad weather, or the engines iced up during the climb?
Absolutely you tell them to standby. It was suggested that you don't do anything proactive until they declare which is not the case. It looks like we'll find out what happened soon enough. Wasn't the last known altitude 36k ft? Either they had got the message, but didn't acknowledge it for some reason, or they had climbed before ATC gave the ok for 38k ft? Perhaps 36k wasn't high enough to avoid the bad weather, or the engines iced up during the climb?
Vipers said:
Havnt seen any photoes of divers, but if they are using a commercial diving outfit, they will almost certainly use surface gas, thats surface diving breathing Helium/Oxygen mixtures, and if they want any decent bottom time, which they will need if they intend to rig and recover sections, I think they will use saturation diving techniques, with a diving bell.
Using a bell will allow up to 6 hours in the water on the job, then again outwith the UK, some rinky dinky contractors just keep going till someone is knackered.
Bearing in mind the searchlight being on this recovery, and the fact someone wants the plane and bodies back, I think they will go for a recognised commercial diving company. They will need a diving vessel anchored to even think about penetrating the plane.
Any links to photoes of divers anyone.
Seeing that the Indonesian navy found it, they may make a couple of dives to just check it out, and look for the box. But the recovery is something else. As previously said, you could dive on air, but nitrogen narcosis may be a problem.
Just to add in the UK and Norway, commercial divers are allowed to use air to 50 msw, not normally used though.
I'll be interested to see what the dive set up is like ..Using a bell will allow up to 6 hours in the water on the job, then again outwith the UK, some rinky dinky contractors just keep going till someone is knackered.
Bearing in mind the searchlight being on this recovery, and the fact someone wants the plane and bodies back, I think they will go for a recognised commercial diving company. They will need a diving vessel anchored to even think about penetrating the plane.
Any links to photoes of divers anyone.
Seeing that the Indonesian navy found it, they may make a couple of dives to just check it out, and look for the box. But the recovery is something else. As previously said, you could dive on air, but nitrogen narcosis may be a problem.
Just to add in the UK and Norway, commercial divers are allowed to use air to 50 msw, not normally used though.
Edited by Vipers on Wednesday 7th January 11:01
Edited by Vipers on Wednesday 7th January 11:03
If 30m .. non deco bottom time on air is only a few minutes - a bit more on nitrox but not much.. and if nearer 40m then oxygen toxicity could be an issue on nitrox.
.. so my guess would be some form of surface supplied heli-n2-ox mix (?).. but no need for sat diving if the tail is around 30m? .. not sure what the deco time would be with ( say) one hour bottom time on mixed gas with a low n2 content at 25-30m.
[Friends of mine have done wreck diving to 48m, for over 1 hour bottom time with rebreather gear (obviously no helium) .. needed deco]
..
alfaman said:
I'll be interested to see what the dive set up is like ..
If 30m .. non deco bottom time on air is only a few minutes - a bit more on nitrox but not much.. and if nearer 40m then oxygen toxicity could be an issue on nitrox.
.. so my guess would be some form of surface supplied heli-n2-ox mix (?).. but no need for sat diving if the tail is around 30m? .. not sure what the deco time would be with ( say) one hour bottom time on mixed gas with a low n2 content at 25-30m.
[Friends of mine have done wreck diving to 48m, for over 1 hour bottom time with rebreather gear (obviously no helium) .. needed deco]
..
Short of looking in my USN Navy Diving Manual, can't offer any times for you, at 50 msw you would be into deco using air anyway, and as you mentioned nitrogen narcosis kicking in, a nitrox doesn't offer much scope at those depths, high PPO2.If 30m .. non deco bottom time on air is only a few minutes - a bit more on nitrox but not much.. and if nearer 40m then oxygen toxicity could be an issue on nitrox.
.. so my guess would be some form of surface supplied heli-n2-ox mix (?).. but no need for sat diving if the tail is around 30m? .. not sure what the deco time would be with ( say) one hour bottom time on mixed gas with a low n2 content at 25-30m.
[Friends of mine have done wreck diving to 48m, for over 1 hour bottom time with rebreather gear (obviously no helium) .. needed deco]
..
My guess is a surface air dive to try to locate the box's, but any attempt to recover the wreckage, and I think they will have to recover the bodies, they will use saturation techniques if they use a commercial diving contractor, surface gas (He/O2) is not often used, and again the relatively bottom times and number of divers v production is a factor.
Certainly if that was in the UK/Norway sector of the North Sea even at 30 msw it would be a DP DSV (Dynamic Positioning Diving Support Vessel) using saturation techniques.
You mentioned rebreathers, your right there, but not used commercially. It won't be a quick job and won't be an easy one.
RYH64E said:
Vipers said:
It won't be a quick job and won't be an easy one.
It'll be a damn sight easier at 30/50m than it would be in some of the deep oceans! Surely 30m is hobby diver territory and 50m isn't deep in the scheme of things?I have personally recovered a Sea King Helicopter from 75 msw using air (Military diving technique in the 70's), but that was relatively easy, just slide a wire down to the diver, attach it to the rotor head, sorted. Recovered to the surface.
Rigging an object the size of bits of plane without dedicated lifting points is complex, needs carefull planning, risk assessments, detailed procedures and above all, time.
Vipers said:
Rigging an object the size of bits of plane without dedicated lifting points is complex, needs carefull planning, risk assessments, detailed procedures and above all, time.
Risky I'm sure, but depending on what kind of state the hull is in and given the depth, would it not be similar to the way they lifted the US Airways out of the Hudson?
Chuck328 said:
Vipers said:
Rigging an object the size of bits of plane without dedicated lifting points is complex, needs carefull planning, risk assessments, detailed procedures and above all, time.
Risky I'm sure, but depending on what kind of state the hull is in and given the depth, would it not be similar to the way they lifted the US Airways out of the Hudson?Any links to the Hudson saga? Depth?
Just googling the Hudson saga, the aircraft was almost next to the jetty, and it looks like a shore side crane was used, bit different offshore on a heaving vessel, weather will be a factor as well.
Edited by Vipers on Friday 9th January 13:59
Axionknight said:
Balloons are what you either put up at Christmas, or have a feel and get your face slapped. What they used here are called "Lift bags", then again what do you expect from the media.Gingerbread Man said:
Vipers said:
Balloons are what you either put up at Christmas, or have a feel and get your face slapped. What they used here are called "Lift bags", then again what do you expect from the media.
I've never put balloons up at Crimbo. Birthday partys, never Christmas.Good point, I stand corrected, never have I. Remember the Benny Hill sketch, he was dressed as a balloon man, you know used to carry them on bits of string (inflated on helium) and sell them at the seaside.
In the sketch a big busted blond has collapsed and a crowd form, one says "What shall we do"
Benny Hill walks past with his balloons and says "rubber balloons, rubber balloons".
Vipers said:
Rigging an object the size of bits of plane without dedicated lifting points is complex, needs carefull planning, risk assessments, detailed procedures and above all, time.
Only if you want to do it right; having seen footage on the news of a piece of the plane dragged onto the deck of an AHTS with it slamming into the hull with the wave action and bits breaking off as it is pulled over the gunwhale by the winch, the Indonesians have hired yahoos who have no f
king idea what they're doing and it will be blind luck if evidence isn't destroyed or lost.Edited by hidetheelephants on Sunday 11th January 13:27
RYH64E said:
Would the fact that they've found the tail section but not the rest of the plane suggest a mid-air break up? If the plane had been intact when it crashed I would have thought that the various pieces would be fairly close together and that more have been found by now.
I doubt very much it broke up in mid air. The large bits of debris have all been found relatively close together - and te black box pings are quite close to other bits. IIRC parts of the plane shot down over Ukraine were well over 10km away from each other - as the plane broke up in mid air as different parts would fall differently ..
alfaman said:
I doubt very much it broke up in mid air. The large bits of debris have all been found relatively close together - and te black box pings are quite close to other bits.
IIRC parts of the plane shot down over Ukraine were well over 10km away from each other - as the plane broke up in mid air as different parts would fall differently ..
Have they found the other pieces of the plane yet? I thought they'd only found the tail section, and now the black boxes that were in the tail.IIRC parts of the plane shot down over Ukraine were well over 10km away from each other - as the plane broke up in mid air as different parts would fall differently ..
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