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The passenger entertainment system typically displays some information related to flight location, speed, altitude, ETA and so on. Where does that info come fro
by mrabcx 3y ago
The passenger entertainment system typically displays some information related to flight location, speed, altitude, ETA and so on. Where does that info come from ? If it does come from the "Aircraft Control Domain, or ACD" then these two systems are probably not "completely isolated" as claimed in the article?
- mschuster91 3y agoA 10$ GPS antenna can give you this information... just without the performance guarantees that come with glass cockpit equipment.
- kzrdude 3y agoA regular phone can also give you this information, just be seated at the window (I guess) for best reception of GPS data. The GPS test app is nice for this.
- maayank 3y agoCan it though? The chips in 10$ AFAIK have hardware limitation built in to cut/fudge output on high (air traffic scale) speeds.
- zaxomi 3y agoCoordinating Committee for Multilateral Export Controls (COCOM) limits is 1,000 knots (510 m/s) and/or at an altitude higher than 18,000 m (59,000 feet). Commercial airliners usually have a service ceiling at about 40000 feet and a speed below the speed of sound (343 m/s). Even with a very strong jet stream of 100 m/s it's below the limit. The Concorde had a service ceiling of 60000 feet and maximum speed of 605 m/s.
- dharmab 3y agoCOCOM is technically AND, so you can buy some receivers which will work with one or the other condition.
- wafflemaker 3y agoYou can use Open Street Maps to monitor the flight without the internet connection. I often use it to watch how the plane speeds up for take off and slows down for landing. Sometimes you have to keep the phone closer to the window. Luckily you get the list of currently connected GPS sats so you can debug whether hiccups are software/hardware related or poor GPS coverage. It's lot of fun observing how early planes start going down in altitude before landing or trying to guess river and city names from up top.
- sva_ 3y ago> luckily you get the list of currently connected GPS sats How do you get this list?
- etskinner 3y agoThe almanac, which is part of every GPS transmission https://en.wikipedia.org/wiki/GPS_Almanac?wprov=sfla1 https://en.wikipedia.org/wiki/GPS_Almanac?wprov=sfla1
- closewith 3y agoGPS really is amazing. It's hard to believe it works at all.
- fragmede 3y agoMy favorite part about GPS is that it only works because we understand relativity, proving Einstein right.
- dharmab 3y agoIt would work without an understanding of relativity, but the accuracy would drop by about a meter. https://physics.stackexchange.com/a/128951 https://physics.stackexchange.com/a/128951
- 3y ago
- davchana 3y agoI have used Google's My Tracks (now defunct but apk still works) app, and Various GPS Speedometer apps at window seat to get the air speed and such for fun.
- ryandrake 3y agoI don’t know why you are getting downvoted. You are absolutely right. There is no need for any kind of connection to the system that flies the plane, even a read-only one. The entertainment network should be completely isolated and if one of the entertainment apps requires the aircraft’s location, they could use a separate GPS receiver and antenna.
- sva_ 3y agoI've been on planes where you can request that data as json over the planes wifi.
- deleted 3y ago[deleted]
- amelius 3y agoIt can be a one-directional connection. A port that can only transmit, not receive.
- kylebenzle 3y agoAs always, the answer to the headline is, no.
- n_ary 3y ago> Where does that info come from ? If it does come from the "Aircraft Control Domain, or ACD" then these two systems are probably not "completely isolated" as claimed in the article? You are indeed right, there is a connection to the BUS that shares some information. You can also write back some of the information(flight number, flight leg etc.) back to it. However, rest of the things are read-only. So, no way to do weird things like modifying the altitude or ground speed etc. Basically, the main computer is completely isolated from the infotainment system, except for the BUS emitting these minor information. You can however, probably get near the main computer if you can get the jump seat ... Disclaimer: Work in aviation tech.
- closewith 3y ago> Basically, the main computer is completely isolated from the infotainment system, except for the BUS emitting these minor information. Unless this is a one-way optical bus or similar, I'd be very skeptical of that claim.
- gruez 3y agoYou're making it sound like isolation requires exotic components, but a GPIO pin on a raspberry pi is basically one way only unless you explicitly write code to read data from it.
- gte525u 3y agoFWIW - ARINC429 is a common one way serial bus used in commercial aviation.
- closewith 3y agoThanks for this comment. It seems that ARINC 429 has been replaced by ARINC 644 in most new aircraft. From reading the Wikipedia article, they are indeed logically one-way (although the underlying protocol involves two-way communication). It has no security at all. However, it seems that communication between any avionics systems and anything user-accessible goes through a Network Extension Device (NED). These are required to either be physically (not only logically) unidirectional _or_ have built-in security. So it might be physically impermeable or it might be a buggy 10-year old firewall. Doesn't exactly inspire confidence given the subject of the article.
- tyingq 3y agoYou can get the same info at places like FlightAware... https://www.flightaware.com/live/flight/random https://www.flightaware.com/live/flight/random
- notahacker 3y agoYep. Its broadcast by ADS-B transponders. Suffice to say hobbyists with ADS-B transponders and people using FlightAware and its competitors' APIs don't all have write access to flight computers...