Comment by jacquesm | Hacker News Reader

Comment by jacquesm | Hacker News Reader

At any one time there can be as many as 50,000 aircraft in the air. You'll probably need more than one stream to get the relevant action so you're looking at substantially more bandwidth than all the communications satellites currently in orbit would be able to provide (and you'd have to shut down all the other services they carry).

You're also going to have to take into account that aircraft are moving relative to the satellites so you'd need to have a way to keep the antennae aligned (phased arrays or actuated dishes or both depending on which end you're looking at).

The only 'plus' in the whole scheme compared to terrestrial stuff is that airplanes are physically a bit closer to the satellites.

And then you'd need double the bandwidth at the satellite ends for the downlinks (unless you want to store at the satellite and only downlink in case of a crash).

Crack this and money will flow your way in wide rivers.

No need to track 50,000 aircraft. Instead, have the stream automatically switch on when the plane is in distress, when it's losing altitude, when an emergency has been triggered, or when it's going off the flight path.

You have just complicated the system considerably. If you want something to work during an emergency you're going to have to keep it as simple as possible. Also, some emergencies happen so fast that if the system has to switch on 'when an emergency has triggered' then you're too late.

Define: 'going off the flight path'...

In theory this is a simple problem to solve, just install a couple of webcams and hook them up to the in-flight wi-fi. In some cases that might even work. But if you want it to work in all the cases, especially those cases where things are going wrong then you'll need to think this through very carefully or it will be worse than useless.

The other question is what percentage of the time a camera in the cockpit actually adds useful information beyond the conversations and control positions already being recorded?

A camera is pretty trivially disabled or obstructed in the event of foul play; the exception to the rule of communications and black box data being enough to establish what the pilots were trying to do.

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