Who do you think you're fooling?

Gentlemen, may I recall this thread is about resolving the Inmarsat data. Speculations should go to ""Rumors and News".


Someone suggested that the satcom re-logon at 18:25 may have been caused by power interruption. This is not by far the only possible technical explanation of this event.


Propduffer, you appear entirely focused on finding ways everyting was done intentionnally. That just reflects a lack of imagination or knowledge about all that could go wrong aboard an airplane.

Other than a power failure or the modem coincidentally developing a bug that very same night, what other "technical explanation" do you have that would cause a modem to initiate a login?

Gentlemen,

Whether or not this is the proper thread for this particular discussion (though it seems appropriate enough considering it's mostly technical aspects), I dare interject nevertheless.

Propduffer is correct in this instance.

Buzzbox, with due respect, you first agree that the only way to turn off the satellite transmitter/modem from the flight deck is by dropping the left AC bus.

Then, seemingly out of thin air, you disagree all of the sudden and provide no basis for this change of mind, other than to claim that this is 'sensitive information'.

DJ177, with due respect, I feel it unfair to accuse Produffer of a lack of imagination. He has clearly stayed solidly grounded in fact, and the burden is on you or others to factually discredit his claims, which you have failed to do.

@DJ77

I asked about the "log on" at 18.25
It was suggested it was likely a power interruption.

The T7 has a high level of redundancy so I was trying to discover "intentional" and "non intentional" reasons for this from (limited) OFFICIALLY RELEASED information (and where the location of the a/c was).

...and what a "thankless task" that is !

1. After 1.21am MYT (around IGARI) there is nothing.
2. There is no "relevant" data gleamed from the 2.03am MYT/2.05am MYT Inmarsat transmission.
3. There is no "officially released" Primary Radar data. The ATSB Report is "not recognised" by Malaysia, although the "last contact" given by the Malaysians as 2.22am MYT is noted
4. A "new log on" is given at 2.25am MYT, which places the a/c in the Banda Aceh area.
5. There follows a number of "handshakes" recorded by Inmarsat along with 2 "telephone calls", which correspond to the activities MAS undertook.

Like it or not, they are the facts. There is NO overlap in events.

Tawnybird:

I did not disagree with the suggestion 'that the only way to turn off the satellite transmitter/modem from the flight deck is by dropping the left AC bus'. I said that 'it is possible to force the satcom to log off a satellite from the flight deck, WITHOUT de-powering the system'. There is a difference.

The basis for that statement? A few thousand hours flying 777s in airline operations.

The satcom is not completely autonomous from the flight deck. Honeywell was kind enough to provide the flight crew with some control. Most of those functions are not normally used by the flight crew, but they are available.

@BuzzBox

As a way of "resolving" this "log off and Log on" issue which is believed to have occurred at "some time prior to 1825 UTC" and "at 1825 UTC", you are saying with your time on T7's it is possible to "force" a "log off" without de-powering the system...and without leaving the flight deck.

Assuming you did this. The system has power but is "off line", how would you "log on" again ? Would this be something that would be "automatic" ? Or a "manual" function ?

@ tawnybird
At least, by saying that there is no need to "de-power" the left FMC in order to take control of the T7, BuzzBox has a more solidly grounded point than Propduffer.


@JamesGV
Formally, the log on at 2.25am-MYT is on the relevant Inmarsat-computed ping arc. It is assumed close to Banda Aceh only due to the existence of the radar track of an UFO believed to be MH370. I mean this has never been a certainty.
As I understand the works of RichardC10, Gysbrecht or Hyperveloce, when the 2.25 log on is assumed close to Banda Aceh it appears impossible reconcile the Inmarsat data and possible trajectories without large variations of ground speed. According to the end of flight analysis in ATSB report of June 26th, the unresponsive crew scenario appear more probable (given available evidence). I am vainly trying to figure out how this could add-up with large speed variations an neither can I find any logic for intentionally fiddling with speed.

@DJ77

Taking your first point....

"It (the "log on" and therefore what we believe was MH370) is assumed close to Banda Aceh only due to the existence of the radar track".

Are you saying that IN CONJUNCTION WITH the "last/lost conatct" Primary Radar data is it possible to establish that a plot for the "first arc" is possible ?

As in, it is IMPOSSIBLE to establish a plot for this "start point" using Inmarsat data/BFO/Doppler Effect alone ?

Search radars operate at frequencies above 1 gHz, where atmospheric refraction is less of a factor. The Butterworth radar track data photo that was posted some time ago went out to 200 miles, with a gap from around 100 to 130 miles. Using an online radar horizon calculator it looks like flying at 5000', then climbing thru 10000' at 130 miles would produce a gap like that. That would jibe with the claim that MH370 flew "as low as 4500'". However, the radar horizon at 200 nautical miles is about 23000', which does not jibe with the reported last altitude data of 29500'. In my experience, a huge target like an airliner is easily detectable at max range if it is above the radar horizon. Max range of a search radar is typically around 250 nautical miles, and it is a hard limit, determined by the pulse repetition frequency.

If we accept that the Inmarsat arcs and the radar trace are correct then we have a timing anomaly. If MH370 maintained its last known course - the radar track - then we have a problem because it would cover only about 140NM between two ping arcs which are timed at 1 hour and 12 minutes apart. It is speculated therefore that the aircraft took a large and unexplained northerly diversion (the hook referred to in the Australian report) in order to maintain both a plausible airspeed and the timings of the satellite pings. There is as yet, no reasonable explanation of why this should have happened. This northerly excursion would possibly have taken MH370 as far as Port Blair in the Andamans.

In reality there are an almost infinite number of possible courses which could account for the timings including all sorts of arbitrary "holding patterns" and at present we must accept that there is no evidence which can tell us what the real path of the aircraft was during this period.

There is a reasonable explanation which does not require a northward excursion. The portion of the 18:29 (The BTO data was obtained at 18:29, not 18:25) ping ring plots as nearly north - south (NNW-SSE) at the point it is likely to have intersected the flight path of MH-370. The exact point where the flight path intersected the ping ring was at about 6°32'34.04"N 96°42'17.66"E. this is about 20nm east of where the Malaysians have vaguely given it's position at 18:22. I accept the Inmarsat BTO data as accurate and thus ignore the Malaysian position estimate at 18:22.

As you say, the 19:40 ping ring does lie only about 140nm from the 18:29 ping ring - and it is probable that 9M-MRO did cross the 19:40 ring or pass very close to it about 18 minutes after reaching the 18:29 ping ring.

However at that time (about 18:47) there were no satellite communications in progress, so there was never any BTO data collected to reflect that time and place. Thus the 140 nm distance between the two ping rings is meaningless as far as 9M_MRO's flight path is concerned.

What happened at about 18:47 was that 9M-MRO turned south - and when the 19:41 Inmarsat transaction took place and logged the BTO data, 9M-MRO was at about 2°38'57.58"N 94°42'33.49"E (plotted for a 376kt speed) or about 1° 3'43.56"N 94°42'30.43"E if the plane was flying at 470kts.

The 19:40 ping ring also traces an almost north - south path at this longitude so 9M-MRO was on or near that ring for over an hour on its journey south but it was only at 19:41 that the BTO data was collected.

Oldoberon

That's what I mean (Woodpecker is "lost in the trees" methinks).

I am trying to arrive at 2.25am MYT (1825 UTC) and the events surrounding that event.

The SATCOM sys has to go "off line" (either offline or de-powered) prior to this login. (For Woodpecker... the 1825 UTC login !).

For a login, it has to have logged off.
It can't be a dual IDG failure (APU auto starts)
It "could" be a dual IDG failure and APU failure.
BUT what restarts SATCOM ? So it can't be that.
So a "forced" log off ?
Then why does it log on again ?

You see a "mysterious power outage" doesn't explain anything.
As in.... the sys "logged off" before it "logged on" again.

MH370: New evidence of cockpit tampering as investigation into missing plane continues - Telegraph Contrary opinions from other independent informed sources?

Propduffer.....

Or... the a/c "held" off the coast, further south of Banda Aceh.

It is the only way you can get "the fit".
And that means it wasn't a "constant" heading South.
And that doesn't fit the ATSB report *which wasn't written for "this" particular purpose anyway...but did state "a constant heading".

Edit (which is speculation) a "hold" would fit "an a/c in distress", rather than any other suggestion.
Although there are other possibilities, however unlikely they may be.

"It would have to be a deliberate act to hijack or sabotage the aircraft".

.....Which is speculation as he wasn't there.

(And he readily links the 2.22am MYT with the 2.25am MYT log in, without providing specific proof that this was the case, however likely it was).

I don't know what you mean by that.

By "held" do you mean flew in circles? If so, I've never heard that theory before.

IMO it turned south at or near POVUS or NOPEK, and like everyone else I assume that it held a constant speed and course, or GC route until it ran out of fuel. But like everyone else I can't find a speed or route that intersects all the ping rings at the right times.

The only thing you can turn off that affects radar detection is the transponder, which can simply be turned off. So the power failure is NOT "consistent with an attempt to turn the plane's communications and other systems off in an attempt to avoid radar detection." However, it is consistent with an attempt to avoid communication.

It's not a new concept.

https://www.dropbox.com/s/bu7ajeqvhe...ght%20Path.pdf

Edit, that's if there is a route south.
At Banda Aceh a U.K sailor saw a "glowing orange" a/c heading "south". And two other a/c heading "North".

Mention "conspiracy" and they jump on you here !
As an "ex pat" Brit working in the sandpit, I don't believe half the things I am suppose to.
I'm just saying "it either held" (in a hold) or didn't get there at the time specified. (Or "wasn't it")

Where is there? If it's 19:41, there is no need for flying in circles. That time works out with no problem, the location is near 2°38'57.58"N 94°42'33.49"E.

If it's the terminal spot you mean, the where is the question. There are a lot of possible solutions for that. As many solutions as there are discernible speeds. But to where?

The dropbox pix is a non sequitur, it shows the flight path over Indonesian territory. We may not know everything, but we know for sure it never overflew Indonesian airspace, especially Indonesian landmass. That flight path puts the plane almost directly overhead of the Indonesian radar at Lhokseumawe.

The flying in circles premise is utter nonsense, there is no indication of that, there is no evidence for it and it makes no sense. The "sighting" you mention was investigated and came to nothing.