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United used to have a feature called "From the Flight Deck" where you could listen to live radio communications between your pilots and air traffic control.

Unfortunately, it's now only available on a few routes and planes:

https://www.flyertalk.com/forum/united-airlines-mileageplus/...

I found it very comforting to listen to it during an entire flight, because you could find out what the pilots of your flight were actually saying about turbulence and flight conditions, including their ongoing efforts to avoid turbulence purely for passenger comfort. You could also hear from other pilots who had recently flown through the same region, discussing how turbulent it was and how long it was likely to last. Among other things, this can reveal that the pilots are aware of the situation and don't consider it threatening.

Part of the scary thing about turbulence can be wondering "do the pilots realize it's so bumpy?" or "are they concerned about this?" or "what are they doing about it?". Most U.S. flights don't really make a lot of passenger announcements about these questions, but if you listen to the ATC communications, you can get real answers (usually "yes", "not at all", and "trying to get a clearance for a different altitude").

In many regions there's volunteer ground-based coverage for live ATC streams:

https://www.liveatc.net/

It's obviously more complicated to identify the particular ATC region that your flight is in (and then manually change to a different stream every time you're handed off to a different controller!), but if you buy in-flight Internet access, you might be able to listen to some of these communications from the air even if you're not on a United flight with channel 9.

The biggest challenge is that ARTCCs (the high-altitude ATC facilities) have subdivided their airspace into sectors with different frequencies.

For instance if you look at

https://www.liveatc.net/feedindex.php?type=us-artcc

you can see the Denver ARTCC (ZDV) is subdivided into more than a dozen different sectors (and there's no guarantee that this list is even complete). So if you wanted to listen to these communications this way, you'd have to take a rather active role in selecting streams and accept that your flight would probably pass through regions with no streaming coverage.

(Edit: for example you might hear "(your flight number), contact Denver center one two eight point three two five, good day" in which case you would want to switch over to the "Denver Center (Sector 14 High): 128.325" stream. If you succeed in switching in time, you should then hear your flight call "Denver, (your flight number) with you at (altitude)". But if you missed this instruction, you might have to spend an inordinately long time listening to random streams in the hope of hearing your flight's callsign, or do significant research on FlightAware to figure out what sector you might be in. Quite a chore compared to United's service...)



Microsoft’s Channel9 was named after this (United Channel 9), and had the same intention: to be an unvarnished look behind the scenes.

https://channel9.msdn.com/About


Listening to the live radio communications on a flight was eye opening. Turbulence aside, I can usually feel when the plane is moving to a new altitude (either up or down), and while I always assumed it was planned, being able to hear the process of the pilot asking for clearance to move, getting clearance, and then feeling the plane rise or fall took all of the fear out of it.


As a pilot myself, I loved that feature. Too bad they discontinued it, so there is no good reason for me to fly United anymore :)


Yep. I loved to listen to that communication even as a non-pilot... all the way from the ground where sometimes I could hear the discussions about trying to leave the gate (or getting a gate on arrival if we were late) and all the way in between. I use to go out of my way to fly United just because of that feature.

Probably the cheapest value add the airline had, even for the relatively few that probably cared. Oh well....


It'd be interesting to see a service that automated this process for you. Ie if you select your flight it displays a list of ATC streams for each airspace you pass through and allows you to easily switch between said streams.


You should still be able to do this with a cheap RTL-SDR dongle (<$20) and a laptop, though you will probably look pretty conspicuous to the flight attendants


I think there are FAA or airline rules against passengers on commercial flights using aviation radios -- and those rules might include aviation radios that you synthesize yourself.

https://aviation.stackexchange.com/questions/8939/can-i-fly-...

(It seems that the rules are meant to avoid having unexpected devices onboard using aviation-related RF energy, rather than to prevent passengers from monitoring aircraft communications.)


A passive receiver with absolutely zero emission would allow to listen to pilots communications from the seat and would be easy to build. Listening to the tower once in air unfortunately would not be possible (as with any radio operated in seat) - an external antenna would be necessary for that. The problem with any custom built receiver is however its appearance: a strange electronic device which would probably raise alerts at any inspection, so the diy solution would hardly be doable for use in flight.

But if one can get an old analog FM radio, something can be done eaasily. The air radio band (118 to 136 MHz) is just above the FM broadcast band (76 or 88 to 108 MHz), and airliners use AM modulation rather than FM, but old consumer radio FM demodulators demodulate AM as well, so all one needs to do is retuning the radio on airband frequencies. This can be done by altering some values in the frontend and local oscillator LC stages, but sometimes is enough just to widen the oscillator coil to tune the radio a few MHz up. Nobody should object if you listen to an old FM pocket radio with headphones from your seat.

https://hooktube.com/watch?v=5kvxjNeWMxs


You'd be surprised. I thought the same when I brought 2 arduinos in a makeshift carboard box in my bag and had wires sticking out all over from the breadboard.

Not a word, nor even a wayward look.


> Nobody should object if you listen to an old FM pocket radio with headphones from your seat.

I believe the existing rules would forbid even the use of an FM radio onboard.


That would make sense since a traditional FM radio local oscillator does indeed emit radio frequency, but the level would be really low to be able to jam any of the airplane devices.


Last time I listened to that it was a panicked pilot asking Miami Center for a new heading because they were sending us through a thunderstorm. Not really comforting.


Hm, now I'm pretty sad that their site only works with Flash.. Can't even install that on Chrome anymore.


It doesn't require Flash. Every stream has a link like

https://www.liveatc.net/play/kfwa1_zau.pls

which in turn links to a resource like

http://d.liveatc.net/kfwa1_zau

which you can play in lots of tools (two examples are mpg123 and mplayer).


Off Topic.

Listen to the ATC feature (channel 9) on United planes was possibly used by the Sept 11 hijackers.


Sept 11 hijackers possibly ate at McDonald's. So?

You can also listen to ATC with a handheld radio.


So it is an interesting fact at least for me.

I was reading recently about the attack and the very detailed planning that went into it, especially WRT timing.

Also if you a "prepper"/security type dude, listening to ATC for situational awareness is an option.




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