Malaysian Airlines MH370 contact lost

[Ian W]

Originally Posted by toaddy

Did they establish just 'what' the partial ping consisted of ? I was under the impression that the 'normal' scheduled pings were the satellite sending out a query to the plane and measuring the time it took to get the response; that time corresponds to a distance (the circles). If the partial ping was initiated by the plane, did the satellite respond and get a further response from the plane? If it did that would seem to be MORE than a 'normal' ping (3 transmissions instead of 2); certainly not a 'partial' ping. What gives ?

From what has been said the last transmission from the aircraft SATCOM was not a standard hourly 'Are You Still Here' transmission but the initiation of a logon sequence. The 'partial' presumably means the full logon transaction was not completed - there may be more transmissions involved than just 3 and presumably this would need to include the hardware ID of the aircraft.

[Innaflap]

Just to emphasise a matter of physics with the flying fraternity, the restriction on the sub is one of pressure and not depth.

[GlueBall]

but the real importance of finding the wreck and/or bodies is to do a thorough investigation of anything and everything recovered and try to decide the most likely causes of this awful incident. If they do ever learn what happened and how they will be better able to prevent it from happening again, and that benefits everyone.

It would involve forensic psychology, the art of getting into people's minds, because no mechanical failures could produce such a bizarre flight profile.

[olasek]

how do we know that what they are saying about the radar track/waypoints/alt is true?

No, we don't know 100% but for now it is considered a "fact", other agencies (NTSB, AAIB, etc) do not question this yet, Malaysian seem sure they got it right. So if you want to come up with a theory better use what today is considered a "fact" and do not bend facts to your theory... Malaysians did contradict themselves but in rather minor details.

Not one other govt (Thai, Vietnam, Indonesia, Singapore) have confirmed this radar info.

it would rather be impossible for those other govt to confirm what Malaysian radar saw, not to mention their radars were probably much farther from the target. And who knows if Thai radar capabilities are even half as good as Malaysian radars.

[porterhouse]

a year or two to come up with all of the answers to an aircraft accident, , you guys =

No one has any answers, at this point there are only questions, it seems to me your are supplying your own answers conveniently skipping all the hard questions.

[WillowRun 6-3]

Role of ACARS

Would it be an accurate statement to say that the forthcoming investigation will be the first in which ACARS datalink transmissions to and from satellites are used to determine (or, to provide major inputs for determining) an airliner's flight path and location? My understanding is that the BEA looked at ACARS indications of inconsistencies in airspeed in AF447 but not with respect to flight path or ultimate location.

[ironbutt57]

one atmosphere per 10 metres depth..

[MrPeabody]

ACARS Datalink Sub-function

There has been a lot of discussion around ACARS and SATCOM. Some info below on the Data Communications Module function.

"The DCMF supplies the airplane part of ACARS. The ACARS sub-function controls air/ground file transfers and onboard message routing. The message routing process supplies uplink message routing to onboard systems. It downlinks message routing to the ACARS ground service providers (GSP) through a VHF transceiver (Post SB) or through VHF or SATCOM (Pre SB). The ACARS datalink sub-function uses information within each uplink to send the message to the applicable system. The ACARS datalink sub-function also routes downlinks to the path set by the flight deck crew and airplane systems.
The flight crew sets the datalink path through the MANAGER menu of the AIMS flight deck communications function (FDCF). The path preferences are:
VHF
SATCOM (Pre SB)
Auto."

As you may not be aware a lot of operators do not have ACARS through SATCOM and have modified it out of this vintage of B777's; I believe MAS is one of them.

The satellite handshakes were produced through Classic Aero connections for voice communication and satellite telephone.

My guess is that every time there was a major course correction the beam steering unit in the SATCOM was trying to retune the RF signal to keep track with the satellite. This would explain all the pings under 1 hour; = change in course.

[Tfor2]

Certainly the SAR is partly for the sake of the relatives, but the real importance of finding the wreck and/or bodies is to do a thorough investigation of anything and everything recovered and try to decide the most likely causes of this awful incident. If they do ever learn what happened and how they will be better able to prevent it from happening again, and that benefits everyone.

The task will go on for ages. Wiser heads will want to give up, but they need to show that they are continuing, despite the futility. But we have learned lessons. This will never happen again. There will be new rules and regulations. That's the plus side to come out of it.

[mmurray]

Latest JACC media release

Media Release
16 April 2014—pm

The Autonomous Underwater Vehicle, Bluefin-21, was forced to resurface this morning to rectify a technical issue. While on deck, its data was downloaded.

Bluefin-21 was then redeployed and it is currently continuing its underwater search.

Initial analysis of the data downloaded this morning indicates no significant detections.

[oldoberon]

Just a question of interest.

In order to scan equidistance each side of the fish it is obviously essential the vertical axis remains vertical. I haven't seen any stabilisers on the pictures of it , so how does it do that? Gyros and mini thrusters?

[sunday driver]

so how does it do that? Gyros and mini thrusters

For Heavens' sake!

Bluefin-21 » Bluefin Robotics

"Specs"

There, there. That wasn't difficult, now was it?

[micis]

It has a vertical stabilizer that can be seen on the photos
Search for MH370: Underwater vehicle Bluefin-21 deployed to find plane's wreckage
To me it looks like a swimmer on top of the "fin". Technically it make more sense to have a flat bottom an a swimmer on top than a keel.

[Ornis]

WillowRun

the first in which ACARS datalink transmissions to and from satellites are used to determine ... an airliner's flight path and location? My understanding is that the BEA looked at ACARS indications of inconsistencies in airspeed in AF447 but not with respect to flight path or ultimate location.

AF447 transmitted Acars - including position - to the satellite, MH370 didn't, its Acars were VHF only and that function was disabled. It's probably the first time possible positions have been calculated using the timings of the handshake - which were for the satellite telephone only.

[lakedude]

The Autonomous Underwater Vehicle, Bluefin-21, was forced to resurface this morning to rectify a technical issue.

I understand that the "technical issue" was an over depth or over pressure situation. Evidently the Bluefin follows the bottom at a specific height above the ocean floor and if in so doing it gets too deep it aborts the mission and returns to the surface.

Frankly I'm shocked at how limited the programming is on the Bluefin. Returning to the surface is a huge waste of time and near as I can tell the 2nd worst possible outcome. The worst would be self destruction from over pressure, at least that didn't happen.

I would think that just maintaining a safe depth and skipping over the sections that are too deep would be preferable. Turning around to avoid the deep sections would work as well. This silly thing is kinda like a Roomba that shuts off if it hits a wall...

Putting on my McKayla "not impressed" face...

[Profit Max]

Originally Posted by lakedude

I understand that the "technical issue" was an over depth or over pressure situation.

Source?

The "overdepth" situation occurred when the vessel re-surfaced early during the first deployment. It was then re-programmed (presumably to avoid this situation from happening again) and re-deployed. It then re-surfaced early again during the second deployment due to a technical issue that was not specified in more detail.

[underfire]

Looks like the mission was aborted a 3rd time...

They should be simply flying the fish at its working depth, and forget skimming the bottom.

The sidescan can fly quite a bit higher and still have great res.

[Leightman 957]

News and links

>Looks like the mission was aborted a 3rd time...

I have found mention of two attempts but not three. This and many other posts include bits of information but no source. The slow pace of new information is resulting in a lot of invented stories prompted by reporters' deadlines, old news, patently false news, and theories disguised as news. Major news organizations are as apt to do this as sensationalist news organizations. Excepting press conferences from the search authority, claims of 'new' information do not mean that information is accurate. New 'news' must wait for corroboration to become accurate.

It would be very helpful to me and I imagine many thousands of others if posters here would include links to the stories they cite.

Even better would be for posters to report information sources they have found to be consistently accurate, timely, and resistant to inventive journalism.

[Red Plum]

underfire

They should be simply flying the fish at its working depth, and forget skimming the bottom.

The sidescan can fly quite a bit higher and still have great res.

Had you thought of giving AVM Houston a call and offering your nuggets of wisdom?
Those operating this sophisticated equipment obviously fall short of your level of expertise

[roninmission]

Reliable Sources requested

The most obvious one is JACC

Media