
Expert Was Needed to Disable Malaysia Airlines Jet Systems - pzaich
http://online.wsj.com/news/articles/SB10001424052702304914904579439653701712312?mg=reno64-wsj&url=http%3A%2F%2Fonline.wsj.com%2Farticle%2FSB10001424052702304914904579439653701712312.html
======
waterlesscloud
I was reading up on the Primary Flight Computer (PFC) of the 777, just out of
curiosity.

It's a triple redundant system, that is there's 3 separate PFC systems. That's
not too surprising.

What did surprise me was that each of the 3 PFCs has 3 channels, and each
channel is a CPU from a different manufacturer (AMD, Motorola, Intel). The
reasoning is that any flaw in any particular cpu design would be outvoted by
the other two.

They appear to use 3 different compilers for this reason (Ada), one for each
processor. Seems like the I/O and endianness of the various chips would add
complexity too.

I wonder if the added complexity makes it a net win or loss for safety? I
guess a win, since that's what they do.

~~~
wyager
>They appear to use 3 different compilers for this reason (Ada)

I understand why Ada is used for safety-critical applications, but I have to
wonder: Does the fact that Ada is a relatively old and unfriendly language
lead to more bugs than it prevents? My mind would probably go blank if I had
to stare at Ada code for 8 hours a day.

What if we used Haskell for all non-realtime safety-critical functionality in
aircraft? With a few extra rules to prevent stack overflows, I think I'd trust
a million-line Haskell program over a million-line Ada program (although it
would probably be more like ten-thousand-line Haskell program vs million-line
Ada program).

~~~
protomyth
Ada is proven in this area and generates fast, efficient code that is suitable
for embedded systems. Ada's last revision is 2012. What do you find
unfriendly?

I would most certainly not trust Haskell over Ada in embedded system work.

~~~
codygman
I'm sure someone once made the same comment about Ada when compared to
competing languages (C? Assembly?) too ;)

~~~
protomyth
The history of Ada is about these type of systems. Haskell's history and
runtime characteristics aren't.

------
mutagen
Anyone interested in this event or feeling inclined to speculate on the cause,
mechanisms, and outcomes of the disappearance of Flight 370 should read a
couple of the most recent threads on the topic over at airliners.net[1]. Their
forums are the equivalent of HN for pilots and other aircraft professionals
and are a fascinating read anytime an aircraft event is worth discussing.

[1] [http://www.airliners.net/aviation-
forums/general_aviation/re...](http://www.airliners.net/aviation-
forums/general_aviation/read.main/6024376/) \- Currently the most recent
thread.

~~~
ams6110
pprune.org is another one

------
joyofdata
If this was a movie plot it would be bashed for being unrealistic ...

"It doesn't make any sense somebody could hijack a plane that easily - you
know, just deactivate the transponder and be gone - it's not that simple, of
course - that would be ridiculous - and there is radar everywhere. Also the
earth is covered with photo satellites - they would find the plane in no time
- you know, a plane is a pretty big thing - haha - so anyway, bit naive, but
the acting was alright - so if it wasn't about the transponder plot hole I'd
give it a solid 8 ..."

~~~
heartbreak
If? You mean _when_ this story becomes a movie plot. I give it one year after
they find it.

~~~
tomelders
This seems like a great place for me to add my wild and crazy crack pot 99.99%
likely to be total nonsense theory to the cacophony of other similar
theories... which would make a great plot device for a movie none the less.
I'll give you the cliff notes version

When handing over from one ATC to another, MH370 adopted the identity of
another plane in the area, and the other plane switched off it's transponders
(let's call this other plane AB123). Leading to a scenario where the whole
world is looking for a plane in the sea when it's actually airborne, but just
happens to look like another plane on radar, and they landed it at some
backwater airport (AB123's destination) that's under terrorist control (for
example, how big a team would you need to take over Port Blair Airport on the
Andaman islands? I'm guessing not very many, and no would be any wiser if you
ran it as normal)

But why do this? Because whoever stole this plane needs to be able to fly
MH370 into someones airspace unnoticed to do something bad, and flight AB123
is scheduled to fly into that airspace sometime soon, but if flight AB123 had
been hijacked, or had gone missing, it would raise alarms. But to the outside
world, flight ABC123 is fine, it's MH370 that everyone is worried about... but
flight AB123 is MH370.

So where is AB123? I don't know. Maybe thats the plane the oil rig worker saw
crash, or maybe they figured out some other way to hide it. Perhaps both
planes flew to AB123's destination, but with one flying directly above the
other so that it looks like one plane on radar (I don't know how Radar works
but this would work for a movie) Also, AB123 might not be a passenger jet, it
could be a cargo plane, or some other kind of plane that doesn't come with a
bunch of passengers that people would miss.

Anyhoot, that's my crazy theory and even I don't believe it, but a small part
of me hope's it's right because the people on Flight MH370 could still be
alive.

At the very least, I think this is a good plot for a movie.

~~~
hga
Complication: when the plane's "secondary radar" stopped (the transponders
that report things like ID and altitude), both Malaysian and Vietnamese
"primary radar" could still see it (the unassisted bounce back of the radar's
radio waves). If they saw two biggish pips in the general vicinity they'd
likely have said something by now, at least the Vietnamese, who've got to be
getting annoyed by Malaysia's handling of this. E.g. per Wikipedia '
_According to the Vietnamese deputy minister of transport, Pham Quy Tieu, "We
informed Malaysia on the day we lost contact with the flight that we noticed
the flight turned back west but Malaysia did not respond."_'

~~~
tomelders
I don't know what you're saying, but I assume you've found a fundamental flaw
with my theory. Two biggish pips?

~~~
hga
Sorry, I wasn't clear enough, and thinking further, probably wrong on the main
point:

You postulate two planes in the same area, that would look roughly the same on
primary radar when their transponder was off (or maybe I misread you/assumed
incorrectly about both looking big, see below). "Biggish" in that the 777 is a
rather large aircraft with a presumably large radar cross section, "pip" as in
a blob of light appearing on the radar's screen.

Going further, when they looked at the recordings of what their radar(s) saw,
they'd see one "biggish pip" suddenly returning transponder information and
another stop ... it's hard to imagine coordination to the split second,
although it's possible.

Ah, I see one way in which I could be wrong: assuming the use of a small jet,
it could be configured with a powerful enough transponder to simulate the
777's. So both pips would not necessarily be big, and if the location was
carefully chosen maybe the small jet's wouldn't be seen by the radars. And
that's more likely, after all, if they had a big jet to start with....

~~~
tomelders
So what you're saying is I'm 100% correct and this is definitely what
happened?

But back to being serious for a second. If mh370 really did keep on flying for
five hours on the route that has been suggested, is there any other way it
could go unnoticed? I'd like to think that it's impossible for something the
size of a 777 to fly unhindered through the sky over several countries post
9/11\. But then again, I had hoped someone couldn't make a plane vanish
seemingly at the flick of a switch.

You seem to know your onions, is it possible to have two planes flying close
enough together that they show up as one blip on radar? What's the pixel to
kilometre ratio on those things?

~~~
hga
Heh, I deduced a way it might be possible, assuming sufficient coordination.

I don't know specifics of radar, just the general principles. The major
possibility here is that your suggested transfer of which transponder is
saying "I'm MH123 at the same altitude" happened at a range where no radar
would be giving a good enough return from the putative small jet assuming the
role. Which upon review wasn't the scenario you were positing.

And if it was giving enough of a return to be seen, especially in retrospect
as experts reviewed it, well, we'd have heard about it by now.

But if AB123 was big, we'd really have heard about it and it's near collision
with MH370, or someone would be wondering why AB123 moved _really_ quickly a
noticeable distance at the same time MH370 went off the air. Or perhaps
AB123's altitude was different, they were far enough the radars' couldn't tell
that, and it's transponder was customized to lie about the altitude.... But
people would still wonder, and would be questioning AB123's flight crew if
they saw anything, etc. etc.

(I'm tired enough the above isn't entirely coherent, but it'll give you some
things to chew on.)

~~~
tomelders
Again, I would like to stress that I know all of this is unlikely, but there's
is no reason why both planes would need to coordinate this down to the second.
Mh370 goes offline, takes an hour to get into position with ab123. Then they
make the switch.

Once mh370 goes missing, it stays missing. The trick is in making it look like
ab123 is behaving normally. And while everyone is distracted by the search for
mh370, I wonder how closely they would be looking at irregularities in other
flights that aren't missing and aren't reporting any problems.

~~~
tomelders
Looks like two planes can fly close enough together to look like one plane on
radar...

[http://keithledgerwood.tumblr.com/post/79838944823/did-
malay...](http://keithledgerwood.tumblr.com/post/79838944823/did-malaysian-
airlines-370-disappear-using-sia68)

------
ronnier
Malaysian investigators conclude flight hijacked.

[http://www.cbsnews.com/news/malaysia-airlines-
flight-370-mor...](http://www.cbsnews.com/news/malaysia-airlines-
flight-370-more-sinister-theories-still-no-answers-in-search-for-missing-
plane/)

------
bhouston
Some people say that the parallels to this ghost plane incident a decade ago
are increasing:

[http://en.wikipedia.org/wiki/Helios_Airways_Flight_522](http://en.wikipedia.org/wiki/Helios_Airways_Flight_522)

~~~
fourstar
Pretty sure that was posted by a single redditor (for 3 hours)
[http://www.reddit.com/r/AskReddit/comments/20fmd0/serious_ma...](http://www.reddit.com/r/AskReddit/comments/20fmd0/serious_malaysia_airlines_flight_370_megathread/cg2uo2v).

Who else is saying this and where?

~~~
Sniffnoy
Charlie Stross wrote a blog post mentioning it a few days ago:
[http://www.antipope.org/charlie/blog-
static/2014/03/a-hypoth...](http://www.antipope.org/charlie/blog-
static/2014/03/a-hypothesis.html)

------
gkoberger
EDIT: Currently it looks like I'm completely wrong:
[http://hosted.ap.org/dynamic/stories/A/AS_MALAYSIA_PLANE?SIT...](http://hosted.ap.org/dynamic/stories/A/AS_MALAYSIA_PLANE?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2014-03-15-00-22-45)

\------------------------

Disclaimer: I know nothing about planes.

That being said, this seems like fodder for conspiracy theories and click
throughs. Under normal circumstances, yeah, I bet it's hard to disable.
However, if we assume the plane crashed, we know there was a massive
malfunction -- seems more likely to me that it was a part of that.

~~~
jeswin
I reach for occam's razor almost reflexively; I am inclined to think that the
plane will be found around the area we lost contact.

However, the fact that India and the US is deploying so many assets on the
other side makes me suspect they might have some credible leads. I am guessing
India is possibly working more with the US than anyone else; given that India
wouldn't want China to know what capabilities they have there.

~~~
InclinedPlane
Occam's razor only applies to theories that actually explain all the available
evidence. That theory does not.

~~~
tomelders
It's getting to the point where whenever I see someone invoke Occam's Razor, I
stop reading. People seem to think it means "The explanation is always
simple", but what it actually means is "the hypothesis with the fewest
assumptions should be selected."

On the disappearance of MH730 it seems a lot of people are happy to make the
unfathomably large assumption that this was "probably" a catastrophic
mechanical failure and that the plane has crashed into the sea, despite the
conspicuous absence of any evidence for this scenario such as mayday calls, or
a wreckage and now, in the face of overwhelming evidence that directly
contradicts the theory that the plane has crashed (because it appears to have
been under the control of a skilled pilot for five hours after it went
missing, and skilled pilots are usually pretty good at landing planes) people
are still positing the notion that the plane has crashed and that Occam's
Razor somehow supports this point of view.

In short, "the most likely explanation" in this case, is the one that makes a
boat load of wild assumptions.

~~~
TrevorJ
It is also not a scientific argument, but a philosophical one.

~~~
tomelders
That's a much more succinct dismissal of Occam's Razor than my rambling
vitriol.

------
hindsightbias
You don't need an expert if there's a fire in the cockpit:

[http://www.avherald.com/h?article=44078aa7&opt=0](http://www.avherald.com/h?article=44078aa7&opt=0)

Answers are in the past.

------
vannevar
Everyone seems to be jumping on the hijacker theory, but I have yet to see any
evidence to contradict the theory of a fire aboard the plane. It explains the
sudden course change, the failure (or deliberate shutdown) of some electrical
circuits, and the altitude change (an effort to starve the fire of oxygen in
the unpressurized regions of the aircraft).

It seems like aircraft fires occur more often than hijackings. Is there any
reason at this point to prefer the hijacking theory, other than that it's a
bit more sensational?

~~~
TrevorJ
The engines 'phoned home' long after the plane went off the radar so to speak.
The altitude data has also been said to be unreliable.

~~~
vannevar
That doesn't contradict the fire theory, though. It simply means that the fire
didn't directly bring the plane down, but it could still have incapacitated
some of the systems and possibly the crew.

------
mstrem
I get the feeling no one has a clue yet. It is easy to come up with
theories... e.g.

Malfunction in plane - transponder turns off - cabin loses pressure (and
everyone on plane goes unconscious or similar) - because cockpit is locked
crew does not manage to do anything in time - plane keeps on going - fuel runs
out.

of course that is probably totally wrong.

One thing though - if it did fly low over land - I would expect at least
someone would have used their cell phone - so I would rule out that option.

------
Myrmornis
I haven't seen any explanation of the statement that the plane's location was
thought to be within one of two "corridors" in completely different places --
a northern one extending to Kazakhstan and a southern one extending into the
southern Indian Ocean. Is this indeterminacy expected? Is it the result of
some sort of geometrical symmetry? I imagine someone here knows?

~~~
hga
It's based on the reception of the pings at the IMMARSAT geosync satellite.
Look at a picture, e.g., here:
[http://en.wikipedia.org/wiki/File:MH370_last_ping_corridors....](http://en.wikipedia.org/wiki/File:MH370_last_ping_corridors.jpg)

The "corridors" are actually geometrically symmetrical arcs as you suspect,
somewhere around which it's believed the plane traveled until the pings
stopped, presumably because the engines stopped running.

~~~
Myrmornis
Thanks! According to sources [1, 2] there was a period of time during which it
was pinging multiple satellites. Surely this symmetry doesn't persist in a
dataset comprising pings at different times to different satellites (which
themselves are moving)?

[1]
[https://en.wikipedia.org/wiki/Malaysia_Airlines_Flight_370](https://en.wikipedia.org/wiki/Malaysia_Airlines_Flight_370)

[2] [http://edition.cnn.com/2014/03/14/world/asia/malaysia-
airlin...](http://edition.cnn.com/2014/03/14/world/asia/malaysia-airlines-
plane/index.html?hpt=ias_c1)

~~~
hga
They're in geosynchronous orbit, so they rotate with the earth, are always
over the same spot on earth at the equator.

Don't know which satellite series is used for this service, but the Inmarsat
constellations aren't particularly large:
[http://en.wikipedia.org/wiki/Inmarsat#Satellites](http://en.wikipedia.org/wiki/Inmarsat#Satellites),
so it could be they only got solid data---and it's not very specific---from
one satellite.

I also wouldn't put much confidence in mass media reports saying "satellites",
and the Wikipedia plural use is probably based on them.

------
jevinskie
Does anyone know of a plot of the hourly satellite ping locations? The article
made it sound like they contained GPS coordinates.

~~~
ams6110
One is posted here.

[http://www.pprune.org/rumours-news/535538-malaysian-
airlines...](http://www.pprune.org/rumours-news/535538-malaysian-airlines-
mh370-contact-lost-175.html#post8376066)

------
uptown
This article alludes to one circuit killing both transponders, but I'd seen
reported elsewhere that there was a 14 minute gap between when the
transponders became innactive. Wouldn't that gap lend credibility to them not
being disabled by a single circuit?

~~~
joering2
jamed by AWACS?

Owners of this patent [1] were all aboard the plane. The only remaining owner
is Freescale Semiconductor, owned by Rothschild family.

[1]
[http://truthnewsinternational.files.wordpress.com/2014/03/us...](http://truthnewsinternational.files.wordpress.com/2014/03/us008671381.pdf)

~~~
_delirium
That patent seems like a thin hook to hang a conspiracy theory off of. It
looks like a run-of-the-mill "optimize placement of stuff in a slightly
different way than other people have done" patent, of which there are at least
hundreds yearly.

~~~
joering2
um, "optimize placement of stuff in a slightly different way than other people
have done" and save billions of dollars over the span of time, due to very
high price of silicon wafers?

ok.

~~~
_delirium
Most likely not; it's just another minor process variation, like the thousands
of such patents that exist. Is there evidence that this patent is a
particularly novel or important one?

And furthermore, what motive would someone have to knock off the inventors
when they no longer even own the patent? If you look in the document, you can
see that it has an single Assignee, Freescale Semiconductor. When a patent has
been "assigned", the original inventors give up any proprietary rights in the
invention to the Assignee, which is the normal process with corporate patents.

------
bdonlan
The article talks about needing to pull a circuit breaker to kill the
transponder - I thought the transponder had a mode selection switch on the
pedestal that could be set to standby; is there something else to it that I'm
missing?

~~~
choult
Presumably it needed total disabling, not just switching off...

------
threeseed
Makes you wonder about the logistics of this all.

Moving around the plane opening hatches and tinkering with equipment requires
there to be at least a few people. One to do the work, one inside the cockpit
managing the flight and one looking after the passengers. All of them you
would assume would have guns to keep the passengers from simply rushing them.

Getting multiple weapons past security surely means an inside job. And then
what is the motivation for multiple people wanting to hijack this particular
plane ?

~~~
will_asouka
Flight deck doors are secure also, and the first action on attempted hijack is
divert to the nearest suitable. It looks increasingly likely that one or both
pilots remained in control.

------
georgeecollins
Here is my conspiracy theory: If you were the FSB, you would want to distract
popular attention from events in the Ukraine. A lack of news coverage of the
events in Crimea takes the heat off Western leaders to look tough.

------
cfreeman
Is there any legitimate reason for the pilot to disable the transponder? It
seems like they should make it more difficult than just throwing a breaker in
the cockpit.

~~~
lutusp
> Is there any legitimate reason for the pilot to disable the transponder?

Yes, of course -- any piece of electronic equipment might (a) begin to
misbehave and interfere with other equipment or produce misleading results, or
(b) catch fire and emit smoke into the flight deck, or (c) both. It's common
sense to have a way to disable any piece of equipment on short notice.

I played a small part in the design of NASA's Space Shuttle many years ago,
and we definitely kept the possibility of equipment failure in mind at all
times.

> It seems like they should make it more difficult than just throwing a
> breaker in the cockpit.

On board an aircraft, the pilot has the highest authority. You don't expect to
have to protect the aircraft from him -- more the reverse. That is why, when a
pilot goes crazy, the results are usually catastrophic.

------
kayoone
Or it might have just malfunctioned because of other fatal malfunctions
leading up to the Crash.

------
romanrage
Well, the question is still is Missing Malaysia Airline Plane MH370, Where It
Disapear ?

[http://feedingnew.wordpress.com/2014/03/13/mystery-of-
missin...](http://feedingnew.wordpress.com/2014/03/13/mystery-of-missing-
malaysia-airline-plane-mh370-where-it-disapear/)

------
lazyjones
The 777 is fully FBW apparently and many (all?) sensors communicate
wirelessly. What are the chances that it was hacked by a passenger or remotely
and taken over this way?

~~~
gvb
Wireless sensors? [Citation needed]

I don't have direct experience with the 777, but do with the 787 and other
aircraft systems. I am not aware of any wireless sensors. There are a lot of
sensors which communicate with the various computers over multiplexed _wired_
data buses.

ARINC 429 is a legacy, but still heavily used, digital data bus.

ARINC 629 is used on the 777.

ARINC 664 is used on the 787 (and Airbus A380).

The military systems and some commercial systems also use MIL-STD-1553 and
other digital busses.

All wired.

Ref: [http://en.wikipedia.org/wiki/ARINC](http://en.wikipedia.org/wiki/ARINC)

------
Thiz
Occam's razor, the plane exploded in mid air.

Not even time to mayday.

~~~
logicallee
Occam's razor is that nuclear power plants don't exist, they're just coal
power plants (which already existed) with a story about nuclear power being
possible. After all, do you have any idea how complicated controlled fission
would have to be? It's easier if it doesn't exist.

The problem with this "theory" is that it doesn't explain all the evidence.
Sure, a hijack would have to be way more complicated than a mid-air explosion,
just like a nuclear power plant would have to be way more complicated.

But a complicated set of transponders turning off with sudden radio silence is
exactly what happened. Plus, if it was a mid-air explosion - where are the
pieces?

~~~
wcummings
>Occam's razor is that nuclear power plants don't exist, they're just coal
power plants (which already existed) with a story about nuclear power being
possible. After all, do you have any idea how complicated controlled fission
would have to be? It's easier if it doesn't exist

This is ridiculous. An elaborate conspiracy to fool people into believing in
nuclear power isn't simple at all. Not to mention events like Chernobyl

~~~
mason240
Yeah, Occam's Razor in that scenario would be that the nuclear power are real.

