
How do you track a plane? - ColinWright
http://www.bbc.co.uk/news/world-asia-pacific-26544554
======
JoshGlazebrook
The more this story unfolds, the more I realize just how wrong I was about how
I thought things like FlightAware and everything involved in tracking an
airplane works.

What exactly is the barrier between just having two way satellite
communications on every plane for the purposes of tracking and reporting its
location?

~~~
jib
Cost mostly if I got it right? The value in knowing the position doesn't
justify equipping all airplanes with some kind of satellite position update
system (the two-way part that is), and there is almost no value in that
information outside freak incidents like this.

~~~
joshberry
I would have to assume that at some point the cost of two dozen countries
looking in between every nook and cranny of 1/3 of the planet exceeds the cost
of a two-way position updating system, not to mention the value of being able
to avoid even one disaster like this and whatever potential related disasters
we have yet to see.

~~~
DanBC
Yes, now that a plane has disappeared (instead of just being flown to a
different airport and hostages kept; or being flown into a building) means
that there is a reason to implement costly tracking devices that previously
had little use.

I used to build devices for aerospace. These were groundside, never ever
airside. The systems (and thus costs) for building these devices were
extensive and complex. Every item, every component, every screw, every washer,
all the chemicals (paint, conformal coating, etc) could be traced from a
finished unit (via its serial number) back through the manufacturing chain.
When my company moved from a paperworks systems (suprisingly good) to
computers (unsurprisingly flawed) they kept the paperwork system for these
products because it was so important to never fail audit.

It's easy to look at consumer grade off the shelf systems and think that the
cost would be maybe four or five times higher, but I think the cost would be
significantly greater.

Add to that the difficulty of getting any component on a circuit diagram
changed and the need to continue producing these units for every aircraft for
many years and there's additional complication there.

------
midas007
So I worked at Trimble Nav in the radio group, so this by no means perfect ||
expert on the first go:

Rough specs of something that might be respectable:

    
    
      - wind & solar powered
      - externally-mounted, self-contained, near zero maintenance
      - compatible with deicing chemicals & equipment
      - multiple redundant location sources: GPS, GLONASS, LORAN, cell-tower 
      - jam-resistant multi antennnae / recvr config
      - highly compressed satellite telemetry with cellular, pager and HF backups
        - location & alt delta every 3 minutes (12 bits +- 100m)
        - absolute location & alt every 8 hours (46 bits +- 100m)
      - physically hardened against several hours blunt-force phsyical damage
        - (eg enough to slow down a die-grinder w/ a diamond cutoff wheel)
      - pretty app similar to google earth where carrier operators can see their fleet live or in the past
    

Unit cost of ~$100k USD at first, getting to $35k at scale

Shoe-string budget dev costs: $1.2 mil for a bump to fit the most popular
model of jet first, then expand to others and airbus if successful.

Assumes engrs that can bust it out quickly and hustlers that can finagle
enterprise & get distribution (Eg make it an FAA mandatory device for classes
of airframes).

------
ChuckMcM
They also omit the fact that the 4 digit code in the transponder is entered
_by the pilot._ When I've flown with friends typically the transponder is set
to 1200 until ATC tells them what number they want them to emit, and then the
pilot sets that number and from then on they know who they are.

~~~
davepage
It is worth mentioning that transport aircraft carry Mode S [0] transponders
which emit a unique ICAO 24 bit address assigned by aircraft registration.
This data is available regardless the pilot-entered 4 octal digit Mode A
transponder code. The transponder can still be turned off, however.

This contrasts to small aircraft which typically have Mode A/C only (no mode
S).

[0]
[http://en.wikipedia.org/wiki/Aviation_transponder_interrogat...](http://en.wikipedia.org/wiki/Aviation_transponder_interrogation_modes)

~~~
samstave
So.... why?

All airplanes should have a MAC address. No plane should have a user-
servicable-power-switch to the transponder.

Can you tell why the opposite woud be needed?

~~~
maxerickson
In case an electrical fault is detected.

Protecting the passengers from the pilot is anyway a false goal. You can't
really do it without removing the pilot.

~~~
samstave
This and: ___(electrical faults, interference with airport radars, safety of
maintenance technicians)._ __

Sound like utter BS.

Show me a case where an IN-FLIGHT transponder shutdown is a needed issue, or
where this does not need a better engineered solution.

Also - Don't tell me why this is not done (based on past issues) - tell me why
this is impossible to fix.

I challenge you to give me any reason in the universe which is acceptable for
not tracking, in real time - uninterrupted streams, flying packages of
hundreds of humans.

Give me any reasonable response to why this is not something that should be
fixed.

~~~
Perdition
>Show me a case where an IN-FLIGHT transponder shutdown is a needed issue

How would the system determine it is in-flight and thus prevent a maintenance
shut down? You would need another device to determine in-flight from ground
operations, and thus another device that can malfunction and thus can be
defeated by an attacker.

>Give me any reasonable response to why this is not something that should be
fixed.

Give me a reasonable response why spending a bunch of money to fix this rare
issue is worth it over other safety improvements? Old aircraft, poor
maintenance, and overworked pilots kill many times more people than hijackers.

P.S. Why don't we track buses? Why don't we track cars? Why don't we track
everybody?

~~~
samstave
>P.S. Why don't we track buses? Why don't we track cars? Why don't we track
everybody?

Buses are at alt==0 and never over an ocean - you're an idiot for comparing
the two.

Why don't we track everybody? Do you understand what the NSA has been doing?

~~~
ColinWright
I'm sure you have valid points to make, but I would ask that you reconsider
how you make them. From the guidelines[0]:

    
    
        In Comments
    
        Be civil. ...
    
        When disagreeing, please reply to the argument
        instead of calling names. E.g. "That is an
        idiotic thing to say; 1 + 1 is 2, not 3" can be
        shortened to "1 + 1 is 2, not 3." 
    

[0]
[http://ycombinator.com/newsguidelines.html](http://ycombinator.com/newsguidelines.html)

------
siculars
What is the first thing you do when you land? I don't know about you, but I
check my phone. If even one phone on that plane was not off or in airplane
mode it would immediately connect with the nearest cell tower no matter where
they landed, if there was a cell tower in range that is. I know for a fact
that I've simply forgotten to turn my phone off... on occasion... and sure
enough, my phone starts ringing as soon as I land.

Now, who here would say that the NSA isn't backdoored into every cell tower on
that planet. I wouldn't be surprised if they are. How could we not know as
soon as one of the cells on that plane popped up on a tower anywhere in the
world? So, exclude all cell tower coverage areas in projected flight area and
search there to rule out potential hijack/landing.

~~~
kevinchen
You're assuming that the passengers are still alive (the plane climbed to
45,000 feet after disabling its transponder), and if they are, that they
haven't been intimidated into giving up their phones.

~~~
zaidf
What does getting the last known cell phone tower contact have anything to do
with whether anyone is alive? Like the OP says, all that is a _single_ phone
making contact with the nearest tower.

~~~
kevinchen
Most people still turn their phones off before a flight to save power or
because they think it will keep them safe. If they are dead, they can't turn
the phones back on and the hijackers can go around searching for phones if
they really want to. So it's pretty unlikely that phones will attempt to make
contact with cell towers.

But assuming that a phone does make contact, there would be massive
cooperation required to detect it. The airline and victims' families would
have to give a list of phone numbers that could be on the flight, and all the
carriers in the region would search through their towers' logs to see if any
of those IMEIs (assuming they keep those logs for at least a week).

~~~
siculars
All it takes is one phone to be on, regardless of human intervention. I would
wager someone forgot to turn their phone off. Nevertheless, if the flight was
hijacked and the hijackers were pros, as they clearly must be, they might have
had a cell jammer. Regarding IMEIs, cell numbers of passengers, and tower
logs, well that's what we have all those 3 letter acronym agencies for. I'm
sure they haven't just been sitting around all this time. I don't think it's
just the navy and air force sending search and rescue.

------
melling
Does anyone know the exact information that the Rolls Royce engines would have
transmitted if the airline had paid for the "basic plan"?

------
shn
Forgive my ignorance, but why the plane could not fly straight rather than
north or south that is put forth as the only options? Straight is as suicidal
as going south, still a vast ocean ahead.

~~~
shn
Somebody down voted a genuine question, and left no comment at all for why did
it? There's no corner of the world short of mean people.

