Malaysian Airlines MH370 contact lost

[DWS]

ABOUT PINGING . .

Does anyone here KNOW how often the ACARS- system on a 777 or on this 777 pings absent a response or ( contract ) to supply engine related data?

Note that BA claims no such contract- and RR also claims no ( engine? ) data after a few minutes before transponder shut down.

I suspect that some technical types consider DATA only to be ( engine parameters and the like ) and the non technical types do NOT consider a simple ping to be DATA … or vice versa depending on background.

And about 99 percent of the media pundits don't know the difference.

So when RR says NO engine data - they **probably mean ** no engine parameters- and do not count a ping per se as DATA

The press probably thinks or defines NO DATA as being NO pings

Yes its splitting hairs or whatever- but his old engineer would consider the ping as " hello- are you there " as an address or attempt to communicate and NOT DATA as its commonly used. I would consider altitude and speed and time as general DATA and Engine parameters as " engine " data .

Lacking one ( engine ) data IMO does NOT mean NO DATA if altitude and speed are part of the transmission.

Back to my question does anyone KNOW the ping repitition rate or ( try every xx minutes or seconds and if no answer to dump data, try again in xx minutes ) ???

[p.j.m]

Originally Posted by D.S.

as it is best understood




as provided by
Disparition du Vol MH370 : la zone de recherche étendue à l?Océan Indien | Air Info

This is the path before adding on the new statement from the US/Malaysia team, which indicates around the end point of the plotted path one of two directions were taken - one in the SW direction toward MEMEK and one nearly due north toward SANAR

According to CNN, the US and India have basically determined one of those directions is where the plane will be found, and that is where the two Countries will be looking headed froward

that plot is at best 2.5 hours, but we know the aircraft was flying for at least 5 hours, with enough fuel for maybe 7 hours or so.

[olasek]

that plot is at best 2.5 hours, but we know the aircraft was flying for up to 5 hours.

There is no contradiction between 2.5 hours and up to 5 hrs.

[porterhouse]

So, Yes, a crew could inadvertently make active a previous flight's route, very easily, in 2key presses of the FMC

No, not that easy, they would be prompted for discontinuity and they would have to acknowledge it and 'fix' it. 2 keys wouldn't do it.

[VinRouge]

Look at the route. It's not part of a recognised route structure. It's following the fir boundary. Why do this? Because if you want to cause max confusion, and you are in the know, you do this to play one airspace against the other, by flying along the boundary instead of,across it until you are outside of radar coverage.

Problem is, with the endurance they had, jet could be anywhere in the Indian Ocean.

[400drvr]

Nice post Evey H

It's very easy to forget there are real people and real families who's lives have been changed forever. For the families involved I hope they have the answers they are looking for and deserve very soon.

[porterhouse]

but we know the aircraft was flying for at least 5 hours

Nobody know for sure how long they were flying.
But per the CNN article and news video this graph ends where they either went North West or South East, watch the relevant CNN video, it is all there.

[Passagiata]

About twice a year, since I joined PPRuNe in April 1997, either Danny or Rob have explained why posts on threads such as this get deleted

Thanks a million, mods, for doing all this and also not closing off this conversation to insiders only. It has been fantastic for non-tech, non-pilot folks to be able to tap in and learn - and stay a jump ahead of the tabloids. We'll go back on the SLF thread when the plane's found...

[KKN_]

Does anyone here KNOW how often the ACARS- system on a 777 or on this 777 pings absent a response or ( contract ) to supply engine related data?

KNOW no - but if one would take the unnamed NYT article sources at face value, handshakes should be frequent enough to estimate (and discard) an apparent 40'000ft change 'in the space of a minute'. Might be extrapolation though (which must use grotesque FL when done from longer time steps).

[jet_noseover]

40K feet drop in one min would make the T7 break apart. Shedding parts, etc.

[Titania]

Navigate by the stars

Do you mean to tell me that pilots would not know to navigate by the stars?

Yes. It's not a commonly needed skill.

Nor would they be able to use the sun by day?

I am left without voice. It may not be a "commonly needed skill" but it's darn useful and I would have more confidence in flying if I knew that failing all equipment the pilots would know where they are and where they go... I was taught as a child, it's not that difficult, no need to be an astronomer...

It's a skill that could have come in handy to the pilots of MH370 on this moonless night without clouds.

[dmurray14]

Originally Posted by DWS

Does anyone here KNOW how often the ACARS- system on a 777 or on this 777 pings absent a response or ( contract ) to supply engine related data?

Note that BA claims no such contract- and RR also claims no ( engine? ) data after a few minutes before transponder shut down.

I suspect that some technical types consider DATA only to be ( engine parameters and the like ) and the non technical types do NOT consider a simple ping to be DATA … or vice versa depending on background.

And about 99 percent of the media pundits don't know the difference.

So when RR says NO engine data - they **probably mean ** no engine parameters- and do not count a ping per se as DATA

The press probably thinks or defines NO DATA as being NO pings

Yes its splitting hairs or whatever- but his old engineer would consider the ping as " hello- are you there " as an address or attempt to communicate and NOT DATA as its commonly used. I would consider altitude and speed and time as general DATA and Engine parameters as " engine " data .

Lacking one ( engine ) data IMO does NOT mean NO DATA if altitude and speed are part of the transmission.

Back to my question does anyone KNOW the ping repitition rate or ( try every xx minutes or seconds and if no answer to dump data, try again in xx minutes ) ???

I know literally nothing about the SATCOM system on the 777, but my take on the situation is that it is similar to cell phones. You can have a cell phone that is not subscribed to any service, however it is still going to "ping" the towers and attempt to register with the network and get online. The network will reject it (as the radio/customer is not subscribed), but they would theoretically have a record of the IMEI/SIM identifier sent to them during the registration process. So, I don't think there is any contradiction here. Assuming the A/C was equipped with the SATCOM radio, whether or not it was actually subscribed, it was likely attempting to join the network on a regular basis. Perhaps as part of the registration header, the A/C sends it's current position (maybe to assist in locating the correct satellite or ground gateway) - but does not successfully register due to lack of subscription. This would corroborate a statement from both RR & Boeing's saying they didn't receive any information from the customer, as well as the fact that the provider (Inmarsat? or whomever it is) received "data" from the plane.

[VinRouge]

Why is it useful? Gps, ins, nav aids, magnetic compass and you want us to get our astrolabe out too?

[mickjoebill]

The airline and nation are probably n complete shock about the only conclusion you can draw from this.

Surely a FBI style investigation of the homes, bank accounts, medical records, telephone records of those with access to the flight deck is underway?

Otherwise there could be an unread note, left on the kitchen table?


Mickjoebill

[xgjunkie]

I think people are thinking far too much into this tragedy.

My belief is it was a simple catastrophic event most probably a serious raging fire and the aircraft was pulverised into tiny pieces upon hitting the sea near its original track.
There have been a few instances in history where that has happened where it left very little debris floating.

My problem with the hypoxia then anoxia theory is should the aircraft had headed west over the malay peninsula, crowded airspace with the transponder off then how come no atc controllers on duty in the area noticed it with primary paint and made a song and dance about an unidentified aircraft being in their airspace. Sure a military facility claims they painted the aircraft but that is not officially released info. If the military painted it then so would the civvies.

I believe this current preoccupation with engine or airframe reporting picked up by inmarsat may again be over-reaching. Are inmarsat absolutely 100% sure they were listening to the accident aircraft? How do they know MAS hasnt been swapping systems on the planes for maintenance and the system registered to mh370 was not on another plane?

As for the terrorism angle, excepting 9/11, most terrorists want to announce to the world what they are trying to achieve, not cloak and dagger so turning off transponders etc... Achieves what advantage for them?

The vast majority of accident sequences end up being very simple indeed. Anything else requires complexity that is outside the limits of most people.

[overthewing]

If any of this turns out to be true, you can see why the Malaysians were flustered. They start off with something that looks like a 'straightforward' destruction /crash, then are gradually presented with a bunch of facts that add up to something almost beyond belief. You'd hardly want to go public with this and look like mad people. The internal arguments must have been fierce.

[porterhouse]

Nor would they be able to use the sun by day?

Pilots have truly numerous ways to navigate these days, neither Sun nor Stars are on the agenda,

It's a skill that could have come in handy to the pilots of MH370 on this moonless night without clouds.

WHY?
There is absolutely zero evidence that these pilots got lost or could no longer navigate.

[physicus]

What FIR boundaries?

My aviation maps for that area do not show the boundaries as depicted in the image p.j.m reposted, only some of the lines (few of them in fact) delineate between Chennai (VOMF), Kuala Lumpur (WMFC), Jakarta, Yangoon and Bangkok (VTBB) FIRs. By leg:
- IGARI-VAMPI crosses in and out of VTBB/WMFC FIRs
- VAMPI-GIVAL follows no boundary and remains inside WMFC FIR
- GIVAL-IGREX remains well inside WMFC.

All based on the (current) SkyVector Hi/Lo alt enroute charts.

What sort of chart was used by the OP?

[p.j.m]

Originally Posted by xgjunkie

As for the terrorism angle, excepting 9/11, most terrorists want to announce to the world what they are trying to achieve, not cloak and dagger so turning off transponders etc... Achieves what advantage for them?

And if thy want x number of aircraft for a future act of terrorism, do you think they are going to tip their hand before they actually commit it?

Personally, I think we need security beefed up, and on high alert at the current point in time.

[misd-agin]

You will not notice turns using 5 degrees of bank UNLESS you are looking outside and using stars for reference when the turn starts.


You will not notice very small rates of climb(100-200' FPM).


The changes are so small if you feel the initial movement, doubtful, if it stays at that pitch or bank attitude for a long time your body will use the increased G (from the 5 degree bank) or slightly increased pitch attitude, as the new baseline.


The best odds of noticing small changes would be if you're standing. Most people don't notice the G loading change, felt as a weight increase, during turns unless they are standing. Your body is more in tune to the weight or pitch changes when you're standing vs. when you're sitting.