HN Explorer

Ask HN: Why don't aeroplanes transmit pictures/sound off the plane?

7 points by hoodoof ↗ HN
Seems a little odd that in 2015 when there is an aviation crash that the source of the data is primarily from the black box recorders.

Why isn't there a camera in the cockpit that sends pictures periodically off the plane to somewhere else? Or an audio log that gets transmitted?

7 comments

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JacobAldridge
Where "somewhere else"? There's an awful lot of ocean without any transmitting towers, and the vast expanse of no receiving ability seems surprising to we landlubbers accustomed to cell phone towers on every other corner.

This was a big debate 12 months ago around MH370.

jacquesm
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.

[dead] no_future
How does in-flight wifi work then?
Throwaway90283
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.
jacquesm
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.

notahacker
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.

saluki
How about multiple ejectable tubes(wing tips, tail and nose locations)that record flight and voice data and are ejected if an explosion or structural failure is detected or if the speed and trajectory indicates the plane will impact the ground. Eject with a small parachute and are made to float, along with a homing beacon, flashing LEDs. And capability to transmits the data to a satellite if possible or maybe even remotely to a surface ship or search team without physically finding the tube.