Honestly, it seems pretty fair to me. If I&#x27;m a careful, occasional driver, and the insurance company otherwise has no way of knowing that, then they have to bill me like I&#x27;m commuting every day in stop and go traffic, distracted by podcasts and who knows what else.There will probably always be a &quot;premium&quot; market for no-questions-asked insurance, but if the company can give me a break on my rate based on my driving behaviours correlating to a lower incident likelihood, I&#x27;ll happily take that break. Even better if such measures correspond to drivers across the board adjusting their habits now that it hits them directly in the wallet.

I did one of those once and tried for three months to drive really carefully.in Boston.it basically broke me and my driving sanity for 6+ months and made me a really worse driver for a while, maybe permanently?? and my rate basically didn&#x27;t change at all.

... Which is precisely the data those data loggers you plug in from insurance companies track to adjust&#x2F;refine your rates  .....

Reminds me of the time I dumped CANbus data off a Yamaha R1 bike, made sense of the data, and displayed it on a bunch of charts.Interesting data like Accelerator Handle position, you can figure out how much a rider is really cranking it, and how aggressive they are riding.

Good luck doing that against Telegram. It would simply reconnect and resume the download where it left off.

I&#x27;d suspect it kills TCP connections once a threshold of data has been transferred, and the threshold is enough to let text through but not enough for attachments.

I noticed the same on Alaska flying last weekend.As soon as I activated the &quot;Free Messaging&quot; service, I got a bunch of notifications from my Apple Home and Google Nest devices.

On iOS all notifications have to use Apple&#x27;s Push service.And the WiFi essentially has to allow the Apple push notification system entirely in order for iMessage to work fully the way people expect.So it&#x27;s really a side effect. But yeah for example with the free iMessage connection on Southwest, I can see all the notifications come in on Discord, but of course I cannot connect within the discord app to actually load all those messages. I can only read them as they come in as push notifications.

United wifi is similar. I&#x27;ve found that notifications work for most things, including my Home Assistant instance—they must all use the same Apple push service.

<a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=33568994">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=33568994</a>

I&#x27;ve been wondering the same.I wonder if they just do some rudimentary packet inspection and drop packets above a certain size. My thinking being that short text messages result in very small packets, while large images will result in many large packets. Dropping large packets is most likely OK. I&#x27;d need to test this hypothesis by sending a very large text message (resulting in many large packets)

I&#x27;ve come across wifi zones which allow normal web browsing, WhatsApp messaging (including pictures), but not WhatsApp calls. I saw it first in Hollyhead Port while waiting for a ferry. WhatsApp threw up an error message saying that calls were disallowed by the wifi network.

Really hoping someone implements this, it’s the funniest project idea I’ve seen in a while :)

I’ve always wondered why I get slack and email notifications when I’m on a Southwest flight with free messaging without paying for wifi. You’ve finally solved my mystery!

I had an idea to use Facebook messanger as a proxy. Specifically to use the cheap messaging plan on a cruise ship for real internet access. My home computer would be a gateway that monitors fb and fetches&#x2F;returns websites. I never even tried because it just sounds like a violation of multiple ToSes. Not to mention message size limitations, throttling, my fb messages being pages of encoded text, etc.I feel like it would need to work like Opera mini to maybe be usable. Even then interactions would be uncomfortably slow.<a href="https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Opera_Mini" rel="nofollow noreferrer">https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Opera_Mini</a>

This reminds me of the old tools that tunnel more or less whatever over DNS. I.e. behind the scenes, the tool would look up &quot;base64encodedpacket.domainyoucontrol.example.com&quot;, and it would respond with encoded data going the other way. This is because captive portal WiFi often permitted DNS to pass through unimpeded, for various reasons.I always appreciated the hack, even though I could never bring myself to use it due to the obvious cache pollution problem on the various DNS servers.

This reminds me of a web browser years ago that would use MMS to transfer web pages to the user without using internet service. This was in the early days. I think it was a Java app for the Motorola razor IIRC

&gt; There&#x27;s this iOS app called FlightlyI guess it&#x27;s Flighty (<a href="https:&#x2F;&#x2F;apps.apple.com&#x2F;us&#x2F;app&#x2F;flighty-live-flight-tracker&#x2F;id1358823008?platform=iphone" rel="nofollow noreferrer">https:&#x2F;&#x2F;apps.apple.com&#x2F;us&#x2F;app&#x2F;flighty-live-flight-tracker&#x2F;id...</a>)I love that people are into this. In the days before iPhones, I had &quot;Microsoft Streets and Trips&quot; + a USB GPS unit + Laptop. It was fun having it on a flight and seeing movement data in realtime. It was less fun answering questions from people who thought looking at the GPS data was somehow nefarious.

Push notifications have background notifications that are used to update apps while they aren&#x27;t loaded. We used them update our catalog&#x2F;home screen on shopping app, its makes the app feel much more responsive when they open the app and content instantly appears instead of waiting for some API calls.<a href="https:&#x2F;&#x2F;developer.apple.com&#x2F;documentation&#x2F;usernotifications&#x2F;setting_up_a_remote_notification_server&#x2F;pushing_background_updates_to_your_app" rel="nofollow noreferrer">https:&#x2F;&#x2F;developer.apple.com&#x2F;documentation&#x2F;usernotifications&#x2F;...</a>

Does that work on Android? I&#x27;ve never seen a non-authorized notification in a Chat or Mail app on a flight.

so why would I use this Flightly app? seems it delivers messages all the same?

It works not because Alaska wants to give you notifications for your messages, but because iMessage literally is transported over APNS.

Hi fellow Alaska frequent flier.So about that! There&#x27;s this iOS app called Flightly that does a brilliant little hack where the app updates itself in (almost) real time on the &quot;free messaging&quot; plan. The way it works (according to a friend) is that their servers send your phone a push notification every couple of minutes from take-off until landing, containing some serialized info such as lat,long,alt,eta,etc. And then the app immediately swallows the notification and deserializes its content without you ever seeing it. The notification works because in order for Alaska to give you notifications at all for your messaging apps, it needs to give you access to _all_ push notifications as they all get sent over an encrypted connected through Apple&#x27;s server and it can&#x27;t pick and choose which apps&#x27; notifications it lets through.I&#x27;ve often wondered if it&#x27;d be possible to pipe any sort of internet over notifications but I&#x27;m not sure if e.g. inline responses are viable, and also that&#x27;d probably be heavy enough usage of push notifications I&#x27;m sure it&#x27;s violate someone&#x27;s TOS.

Is net neutrality even law anymore? T-Mobile has had Binge on for a long time, which zero-rates certain video streaming services. And part of that was even under the old net neutrality laws.

In the US (I believe) Net Neutrality basically died. Even before that, it was allowed to zero-rate categories of apps (like messaging). That might be coming back now that the FCC has 5 commissioners again and can reinstate Net Neutrality.However, even with reasonably strict neutrality, this is still possible. Many mobile carriers zero-rated streaming services here, but unlike your operators they&#x27;d do it for any streaming service. It was pretty easy for any streaming provider to sign up. They&#x27;d basically give the operator the IP ranges they&#x27;d be streaming from and the operator would just zero-rate data to those IP ranges (and they&#x27;d usually apply bandwidth throttling to around 1.5Mbps so that you&#x27;d only get 480-720p video). The key is simply not discriminating between providers within a category.

When the rules were still active, net neutrality did not apply to coffee shops, airlines, etc.&gt; 52. Finally, we decline to apply our rules directly to coffee shops, bookstores, airlines, and other entities when they acquire Internet service from a broadband provider to enable their patrons to access the Internet from their establishments (we refer to these entities as “premise operators”). These services are typically offered by the premise operator as an ancillary benefit to patrons ... Although broadband providers that offer such services are subject to open Internet rules, we note that addressing traffic unwanted by a premise operator is a legitimate network management purpose. [0]It seems like a reasonable distinction: if you&#x27;re letting someone else use your Internet connection, it&#x27;s your prerogative to block things that you don&#x27;t want on your network.- [0] <a href="https:&#x2F;&#x2F;docs.fcc.gov&#x2F;public&#x2F;attachments&#x2F;FCC-10-201A1.pdf" rel="nofollow noreferrer">https:&#x2F;&#x2F;docs.fcc.gov&#x2F;public&#x2F;attachments&#x2F;FCC-10-201A1.pdf</a> (page 31)

Other people have suggested it&#x27;s done by limiting the size of the data transmitted to make the connection only useful to text messages, possibly resetting the connection regularly. If so, it would in fact comply with both the principles of net neutrality and any laws I know of. You could create matsemann&#x27;s text service as long as it also used small amounts of data it guessed could only be used for text.

How does that fly (pun intended) with regards to net neutrality?Where I live, some mobile operators gave you &quot;unlimited streaming&quot; in their data plan, but only for certain popular services (spotify, youtube, netflix basically). Since this would make it harder for others to disrupt the big ones, it was quickly forbidden.

some options:- attachments are likely stored in a different part of the infra than raw messages (like on some s3 bucket somewhere), so it&#x27;s pretty easy to allow the WA&#x2F;iMessage&#x2F;Signal&#x2F;Messenger API while blocking their CDN through dns blocking, ip range blocking, sni inspection, etc.- they cut the tcp connection once more than e.g. 1MB has been transferred. it would result in slightly degraded user experience (the message tcp stream needs to be periodically reopened), and may not be foolproof is apps are smart and resume the download where it failed instead of from the startI lean for the first option as it&#x27;s both the simplest and most foolproof option.

Grindr is a logistics app, Tinder is entertainment :p

&gt; Flightaware.com also worksUnfortunately, I couldn&#x27;t get it to load on my Alaskan flight a few days ago on the free messaging plan. Maybe they&#x27;ve changed it

I&#x27;ve also wondered why Grindr but not Tinder works on the &quot;messaging only&quot; plan. Someone at Alaska must have had fun with that one.Flightaware.com also works, presumably because Alaska uses Flightaware for its tracking map.

Many do but some don&#x27;t. I wrote an HTTP Proxy for Telegram and it works fine for those situations but is very slow. I prefer using an NNCP proxy I wrote because the protocol doesn&#x27;t have online liveness requirements.

Do they allow Telegram?If so, that would be the easiest, Telegram has a really good bot API.

Google Voice always works for me too FYI.

Absolutely. And I&#x27;ll just put this here for anyone who&#x27;s looking for inspiration:<a href="https:&#x2F;&#x2F;www.rfc-editor.org&#x2F;rfc&#x2F;rfc2549" rel="nofollow noreferrer">https:&#x2F;&#x2F;www.rfc-editor.org&#x2F;rfc&#x2F;rfc2549</a>

On my recent United flight, where they had the same policy I was sending image messages to friends through Signal. But it was rather slow, so my best guess is rate limiting.

I always assumed they have a whitelist of iMessage&#x2F;Whatsapp&#x2F;whatever IP addresses. It doesn&#x27;t seem to work for all messaging apps in general.

You could probably have used googels cache to read arbitrary pages as well.

I&#x27;ll probably show my age, but around 15 years ago I was in high school and they blocked most websites as well. This &quot;hack&quot; using Google Translate was how some of us got around the blocklist for many things. It was nice because it didn&#x27;t involve having to install anything special or try to change configurations that were probably monitored by library&#x2F;school admin.

This hack often works today to get around paywalls.

Probably 10-15 years ago when wifi on airlines was still pretty brand new I remember a fun hack for free Internet that involved Google Translate.Because the wifi landing pages used Google Analytics, they allowed traffic through from many of the Google domains. You could then go to Google translate and translate the website from English to English and use it as sort of a proxy server to get free Internet.

Reminds me of using VPNs in hotels in China some years ago. Traffic would work for a few minutes and then the Great Firewall kicks in, fingerprints the traffic as VPN and the IP address and the MAC gets blocked. I&#x27;d rotate the endpoint and the MAC address and get a few more minutes, rinse and repeat.I think I had to use Shadowsocks or something at the end to completely bypass it.

Many years ago, when hotels first started having and charging for WiFi connections, I wrote a simple little tunnel using the DNS port back to my server. Since the hotels didn&#x27;t block that port or even bother to check what traffic was going over it, it worked like a charm.I tried it on a trip to Tokyo and immediately got completely blocked. It took me a few minutes to figure out they&#x27;d blacklisted my MAC address. I changed the MAC of that interface and then behaved.

I don’t think they have any sophisticated solution for sniffing traffic. It’s most likely simple firewall + deals with Apple&#x2F;Meta. Many airlines offer basic Wi-Fi for messages nowadays, so it’s very likely that big tech developed solution for it (especially, as they have initiative to do that, so their apps can work).

&gt; WA chat is not HTTPS (or even TLS)If you don’t mind, could you expend on this? Are there specific reasons to not be using TLS?

I used to work at WhatsApp (until the end of 2019) on many things, including special pricing (aka zero rating); we did not work with airlines, and would not have participated in a project where messages and attachments where treated differently.That said, technically there&#x27;s two pretty easy ways to do it for WhatsApp traffic, and then there&#x27;s the way I suspect they&#x27;re doing it...a) chat runs on different ips than attachments; always has, most likely always will (other than some transitional HAProxy at the old hosting when nearly everything had been moved to the new hosting).b) WA chat is not HTTPS (or even TLS) and attachments are. Chat also cycles between different ports, so you could just block port 443 and be good.c) I actually suspect, based on poking around a little that it&#x27;s mostly just killing connections that use a lot of data. Maybe in combination with some other things. Being on a plane doesn&#x27;t really put me in a debug the network kind of mood, so I never got to the bottom of it, but I&#x27;d regularly be able to make short connections to my home network while on the messaging plan, at least when this stuff was new. OTOH, I think I recall being able to connect through the WA VPN while on a plane on the messaging plan, but that was when we had a publicly available, but not publicly linked list of IP addresses on our website; I have no doubt that DPI vendors had that list.

Most captive portals have gotten wise to this trick and block large DNS requests.

You could try iodine, which is an IP-over-DNS tunnel. This should work unless the gateway has very restrictive rules on where DNS traffic can go.<a href="https:&#x2F;&#x2F;github.com&#x2F;yarrick&#x2F;iodine">https:&#x2F;&#x2F;github.com&#x2F;yarrick&#x2F;iodine</a>

IP-over-Facebook. So that&#x27;s what the world has come to ...

I can&#x27;t seem to find it, but there was a blog post on HN a while back about how someone set up a proxy to browse Wikipedia by sending and receiving WhatsApp messages. I&#x27;m sure you could extend that to be a web proxy.

Hussein Nasser covered this. His videos are great.How Airline WIFI allows Texting but not Media in WhatsApp&#x2F;iMessage<a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=AYSxxO2yZp8">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=AYSxxO2yZp8</a>

So so surprised that nobody has found out the hack for free wifi on alaska flights. (At risk of losing awesome free wifi)1. Open browser with iOS user agent and ios sized h&#x2F;w.
2. Click on t-mobile free wifi link
3. Enter _any_ t mobile number you may know.

I&#x27;m an Alaska (relatively) frequent flyer. That airline offers a free &quot;messaging&quot; plan, that lets you send and receive messages on apps like iMessage, Facebook Messenger and Whatsapp. Though, it somehow prevents images&#x2F;attachments from coming through on those platforms.I&#x27;ve always wondered how this is implemented technically, and if it might be possible to setup some kind of protocol&#x2F;wrapper to send data that looks like it&#x27;s being sent over those protocols, but offers access to other parts of the internet.

Yeah, I was on a long flight home from a hackathon with some fellow programmers so it was fun to work on it together

That&#x27;s cool! I had wanted to make something similar, but I didn&#x27;t have enough experience with making TUIs to build it without using the internet for reference during the flight. I&#x27;m glad to that it&#x27;s been done though!

Thats funny, I discovered the same thing a few months ago and built a CLI flight tracker[1] that uses the API. I&#x27;ve tried it across a couple of airlines and it worked almost perfectly across all of them, because they were all using the same in flight ISP.[1]: <a href="https:&#x2F;&#x2F;github.com&#x2F;NalinPlad&#x2F;OuterFlightTracker">https:&#x2F;&#x2F;github.com&#x2F;NalinPlad&#x2F;OuterFlightTracker</a>

I honestly miss having to debug the racks at pana. But there were so many &quot;what&quot; level bugs with the systems.I remember DRM breaking multiple times for the IFE because they assigned the same IP to multiple devices.

&gt; Your browser could also be retrieving old cached content.No, these are flights I couldn&#x27;t physically have been on. Sometimes it is old content, but it&#x27;s for the flight the plane took previously and doesn&#x27;t update.Here&#x27;s an example of it happening to someone else: <a href="https:&#x2F;&#x2F;community.southwest.com&#x2F;t5&#x2F;Inflight-Experience&#x2F;Flight-Tracker-problem&#x2F;td-p&#x2F;92977" rel="nofollow noreferrer">https:&#x2F;&#x2F;community.southwest.com&#x2F;t5&#x2F;Inflight-Experience&#x2F;Fligh...</a>

If it&#x27;s the panasonic inflight system, it receives flight data from the FMS. If the system does not receive flight data from the FMS then it will not be up to date. Your browser could also be retrieving old cached content.Basically there is nothing about this system to assure you, it&#x27;s entirely a secondary data-delayed system that is not critical to flight operations and as such can be INOP at anytime and no one will care.

Glad someone looked into the flight tracker, I was always curious how real the data in it is.Although it doesn&#x27;t answer my curiosity about how they manage to mess it up occasionally. I&#x27;ve had flight data from different flights pop up a few times on Southwest, which is never reassuring to see.

I felt similar!My best guess is that whoever designed this system preferred to transform the time into a localized (based on the flight&#x27;s location, I guess?) representation on the server so that they could drop it directly into the web UI without much client-side logic.

It looks like the default formatting used by `ctime`. Could be a clue about the underlying backend.<a href="https:&#x2F;&#x2F;cplusplus.com&#x2F;reference&#x2F;ctime&#x2F;ctime&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;cplusplus.com&#x2F;reference&#x2F;ctime&#x2F;ctime&#x2F;</a>

Fun story =)Anyone else freaked out by that &quot;time&quot; format though? Seems like a strange choice, would have expected something more standard like ISO 8601 with timezone offset.
&quot;time&quot;: &quot;Sun Sep 24 22:02:19 2023&quot;

Stupid question: how do civilian GPS units know that they&#x27;re above 60,000&#x27; or faster than 1000 knots without, um, working?

I have pictures from my camera (with location permissions enabled) that don&#x27;t have any GPS data in it, or at least the data is extremely wrong.

I think the &quot;and&quot; in that sentence used to be implemented as an &quot;or&quot; in the days before everyone&#x27;s phones had GPS in them. So you&#x27;d need to power cycle the device before it&#x27;d work again. Now most devices need to hit both limits at the same time before refusing to work.

If you have location permissions enabled in your camera app, the image&#x27;s exif data will have the coordinates in it.(US Civilian GPS units are prohibited from working above 60,000 ft above sea level and 1,000 knots due to ITAR munitions export restrictions.)

I was just thinking that you could take a picture from the window and then tie the GPS coordinates to the image with the output from that JSON. Kind of handy.

Airline planes never use mph but only knots.

Your ground speed plot hovering around 500 mph would be ~800 km&#x2F;h which is oddly slow for an airliner, unless you were facing strong headwinds the entire way.The nautical mile is historically the common unit for marine and air navigation.

487 miles per hour would only be 0.63 Mach which is very slow.487 knots would be 0.73 Mach which is much closer to the rule of thumb 0.78 Mach cruise speed expected.<a href="https:&#x2F;&#x2F;krepelka.com&#x2F;fsweb&#x2F;learningcenter&#x2F;aircraft&#x2F;flightnotesboeing737-800.htm" rel="nofollow noreferrer">https:&#x2F;&#x2F;krepelka.com&#x2F;fsweb&#x2F;learningcenter&#x2F;aircraft&#x2F;flightnot...</a> (and yes, it&#x27;s a simulator but it&#x27;s still good for real world)

Knots are typically used for aviation. Also different planes have their own optimal speeds for efficiency that the airlines aim for so if you know the airframe you can derive what they are most likely targeting. You can also compare the value to the filed flight plan and see if it is similar.

Sorry it seems I was completely wrong, it&#x27;s MPH, your ground speed was on the slow end:<a href="https:&#x2F;&#x2F;www.flightradar24.com&#x2F;data&#x2F;flights&#x2F;wn2340#322ad9f6" rel="nofollow noreferrer">https:&#x2F;&#x2F;www.flightradar24.com&#x2F;data&#x2F;flights&#x2F;wn2340#322ad9f6</a>

Good catch! I&#x27;m not very familiar with knots - what specifically makes the speeds here look like knots to you?edit: Updated the article. Thanks!

... I mean, it could be in nautical miles, no?

Coming at this another way:The blog says the destination was Oakland. The Oakland International Airport is at 37°43′17″N 122°13′15″W. The data packet also contains the current lat and long of the flight as 40.201 and -100.755 respectively. Plugging that in to a distance calculator [2] gives 1163 miles, 1010.6 nautical miles, or 1871.6km. So the distance value of 1167 appears to be miles.At 487mph covering 1163 miles would take 2.3963039014 hours or ~2h23m. If the speed is knots then it would be 2.08233112598 hours or ~2h5m at 560.4296mph. So mph makes the most sense given an estimated time of arrival of 2h25m.So I think you are right, the distance appears to be miles and the speed MPH. This makes sense for an in-flight infotainment system on a US domestic flight.The difference between 1167 and 1163 can probably be explained by the fact that the plane is 6.5 miles in the air traveling at 8 miles per minute and we don&#x27;t know update interval or if the distance is in the air or on the ground.[1]: <a href="https:&#x2F;&#x2F;geohack.toolforge.org&#x2F;geohack.php?pagename=Oakland_International_Airport&amp;params=37_43_17_N_122_13_15_W_type:airport_region:US-CA" rel="nofollow noreferrer">https:&#x2F;&#x2F;geohack.toolforge.org&#x2F;geohack.php?pagename=Oakland_I...</a>[2]: <a href="https:&#x2F;&#x2F;www.omnicalculator.com&#x2F;other&#x2F;latitude-longitude-distance?c=USD&amp;v=coordAngle:0,dmsLat1M:0,dmsLat1S:0,pHLongA:0,dmsLong1M:0,dmsLong1S:0,dmsLat2M:0,dmsLat2S:0,pHLongB:0,dmsLong2M:0,dmsLong2S:0,distPh:0,dLat1:37.721389!deg,dLong1:-122.220833!deg,dLong2:-100.755!deg,dLat2:40.201!deg" rel="nofollow noreferrer">https:&#x2F;&#x2F;www.omnicalculator.com&#x2F;other&#x2F;latitude-longitude-dist...</a>

My bad, you&#x27;re right <a href="https:&#x2F;&#x2F;www.flightradar24.com&#x2F;data&#x2F;flights&#x2F;wn2340#322ad9f6" rel="nofollow noreferrer">https:&#x2F;&#x2F;www.flightradar24.com&#x2F;data&#x2F;flights&#x2F;wn2340#322ad9f6</a>

I&#x27;m not so sure. The same data packet claims that the flight has 2h 25m of flight time left to cover 1167 miles. That works out to 483 mph, which is pretty close to the stated 487 and might be explained by some padding added to the time to account for taxiing.Unless that 1167 figure is in a different unit it doesn&#x27;t even come close to working out at 487 knots ground speed.

I have been on (international?) flights where the in-flight display gave me a choice.  It may still be done on the backend but doing that kind of conversion in the UI is at least arguable.

I don&#x27;t think so. When you use the portal, it displays speed in MPH -- I highly doubt there&#x27;s some knots-&gt;mph converter in the frontend code.

The speed unit looks more like knots than mph.

All chromium-based browsers have it in the network tab of the dev tools

Safari has it out of the box in the web inspector.

Inspect element (F12) &gt; Network tab &gt; when you refresh the screen check the header section to see the raw data. You can right click and copy curl or xor.

What browser or extension has Copy as cURL and all those other functions?

I see you found that TCP relay- I&#x27;ve been dying to try it but I&#x27;ve heard of people successfully using it<a href="https:&#x2F;&#x2F;github.com&#x2F;aleixrodriala&#x2F;wa-tunnel">https:&#x2F;&#x2F;github.com&#x2F;aleixrodriala&#x2F;wa-tunnel</a>

<a href="https:&#x2F;&#x2F;github.com&#x2F;aleixrodriala&#x2F;wa-tunnel">https:&#x2F;&#x2F;github.com&#x2F;aleixrodriala&#x2F;wa-tunnel</a>

Sometimes they just redirect ALL DNS traffic to their little portal until you sign in&#x2F;up.

Many years ago, I noticed I could browse the Google Play Store on a flight WiFi without paying for it. No images would load and no apps would download, but I could browse through app listings and read reviews.Would this be related to DNS?

I&#x27;ve noticed that airline wifi doesn&#x27;t block DNS traffic. You can likely accomplish the same thing with a DNS tunnel like Iodine (<a href="https:&#x2F;&#x2F;github.com&#x2F;yarrick&#x2F;iodine">https:&#x2F;&#x2F;github.com&#x2F;yarrick&#x2F;iodine</a>).

Huh. Maybe this explains why my &quot;messaging only&quot; wifi on Virgin Atlantic a few weeks ago gave me full, slow, internet access?

I happened to have had a flight a day or two after the first beta of Apple’s Private Relay a year or two ago. I was able to use free WiFi the entire flight. Presumably because whatever they whitelisted for iMessage and&#x2F;or push notifications covered that as well. They had blocked it before my return flight days later. ¯\_(ツ)_&#x2F;¯

Airlines already introduce free WiFi to everyone for free. JetBlue does it, Delta also does it for continental flights. Eventually all will, as there is more competition in the tech and prices drop.

Instead of “wow, cool” my first reaction is “free messaging is a great perk, if this is abused they will shut it down”. I guess my hacker days are behind me.

I&#x27;ve not read the EULA but why not just have an actual IP router?Pay the signup charge, and also stand up a wifi network. Call it &quot;Foo discounted&quot; if the plane&#x27;s SSID is &quot;Foo&quot;. Put up a captive portal that lets the user claim various &quot;discounts&quot;, like veteran, senior, child, etc. No matter what they choose, charge them $2 via a payment page. Once you&#x27;ve been made whole on the service cost, future visitors get a notice that &quot;all discounts have been claimed, please use Foo&quot;.Now you have free internet and all those using your router&#x2F;portal have $2 internet. The upstream bandwidth is certainly atrocious so you will easily be able to multiplex all the data onto your connection.Bundle it into a RPi kind of device (has to look finished, like a music player or smth, to get past security) so that you can continue to operate the device even when tray tables have to go up, when you go to the bathroom, etc.I find it extremely doubtful that the airplane has WIPS or WIDS that will deassociate 
connections to your rogue wifi. And after all, are you not allowed to have a LAN party?

Flighty leverages the Apple Push Notification Service (APN), which the iMessage infrastructure also uses. It&#x27;s why you can receive notifications in flight but can&#x27;t act on them.

I believe this is the approach that Flighty (<a href="https:&#x2F;&#x2F;flightyapp.com&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;flightyapp.com&#x2F;</a>) uses to send flight updates while on non-paid Wifi.

A more current alternative: <a href="https:&#x2F;&#x2F;github.com&#x2F;yarrick&#x2F;iodine">https:&#x2F;&#x2F;github.com&#x2F;yarrick&#x2F;iodine</a>

Way back in the day a lot of authenticated wifi firewalls did enable DNS requests to pass through, or at least to resolve using their DNS server, without being authenticated.Someone smart created a TCP-over-DNS tunneling tool that I had a lot of great experience with, at least for more simple news websites of the day.<a href="https:&#x2F;&#x2F;analogbit.com&#x2F;software&#x2F;tcp-over-dns&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;analogbit.com&#x2F;software&#x2F;tcp-over-dns&#x2F;</a>

I want to see someone build a proxy that uses the free iMessage or WhatsApp allowed connection to send arbitrary data.Like have a WhatsApp relay set up at home that you are sending messages to and from, from the plane.Like at a most basic level, send a message of a URL to your home WhatsApp which loads the web page there, and sends the HTML back as a WhatApp message reply so you can render it etc.Wonder what someone could all do and make work.edit Guess someone made a TCP relay using WhatApp already, neat.

I just took two delta flights in the US.  The first had free Wifi through Tmobile.  It marginally worked.  It was just fast enough to view low-intensity websites and I was able to connect to my linux servers back home.

Fun read! Reminds me of the type of articles I would find in 2600. The hacker spirit at work :)

PDT is extremely standard?<a href="http:&#x2F;&#x2F;www.timezoneconverter.com&#x2F;cgi-bin&#x2F;zoneinfo.tzc?s=default&amp;tz=PST8PDT" rel="nofollow noreferrer">http:&#x2F;&#x2F;www.timezoneconverter.com&#x2F;cgi-bin&#x2F;zoneinfo.tzc?s=defa...</a>Granted, I think everything should always be a UTC offset, but I&#x27;m also weird.

Is it really &quot;highly nonstandard&quot;? I thought it referred to Pacific Time during daylight savings. The rest of the time being PST (Pacific Standard Time).

&gt; Specifically, time in this zone is referred to as Pacific Standard Time (PST) when standard time is being observed (early November to mid-March), and Pacific Daylight Time (PDT) when daylight saving time (mid-March to early November) is being observed.<a href="https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Pacific_Time_Zone#:~:text=Specifically%2C%20time%20in%20this%20zone,early%20November)%20is%20being%20observed" rel="nofollow noreferrer">https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Pacific_Time_Zone#:~:text=Sp...</a>.What do you think is the correct format?

Southwest has international routes now to popular vacation destinations south of the US.

&gt; This works because they’re a US-only airlineThey&#x27;re not US-only (note that the response included a value for whether it was a non-US-including flight), but they are North&#x2F;Central America&#x2F;Caribbean-only.

How much more standard can it get?<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Pacific_Time_Zone#" rel="nofollow noreferrer">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Pacific_Time_Zone#</a>
<a href="https:&#x2F;&#x2F;www.timeanddate.com&#x2F;time&#x2F;zones&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;www.timeanddate.com&#x2F;time&#x2F;zones&#x2F;</a>

To anyone claiming they&#x27;re standard:&gt; Time zones are often represented by alphabetic abbreviations such as &quot;EST&quot;, &quot;WST&quot;, and &quot;CST&quot;, but these are not part of the international time and date standard ISO 8601 and their use as sole designator for a time zone is discouraged.&gt; Such designations predate both ISO 8601 and the internet era; in an earlier era, they were sufficiently unambiguous for many practical uses within a national context (for example, in railway timetables and business correspondence), but their ambiguity explains their deprecation in the internet era, when communications more often cannot rely on implicit geographic context to supply part of the meaning.<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;List_of_time_zone_abbreviations" rel="nofollow noreferrer">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;List_of_time_zone_abbreviation...</a>Turns out PST and PDT are safe (no one else seems to use them) but something like CST is not: it could mean Central Standard Time (America&#x2F;Chicago during standard time) or several other choices like China Standard Time (Asia&#x2F;Shanghai).Ambiguity is bad.

Another thing to notice: they use the highly nonstandard time zone abbreviation “PDT”. This works because they’re a US-only airline but if an international airline did this, they’d be in for a world of hurt.

Potentially, but altitude and speed data on ADS-B are constrained to just 11 bits (+ 1 bit dedicated to the resolution: 25 vs 100-feet increments).So while I believe the data source is the same, one can see quantization artifacts when comparing both signals.

Conceivably, the ADS-B data source might be the same as the data source for this API, at least in that they might be calculated from the same instruments and flight systems.

That is the flight. This is a cool idea - I wish I had thought of it!

I belive this is OPs flight if anyone wants to compare plane data with ADS-B one.<a href="https:&#x2F;&#x2F;www.flightaware.com&#x2F;live&#x2F;flight&#x2F;SWA2340&#x2F;history&#x2F;20230924&#x2F;2030Z&#x2F;KSTL&#x2F;KOAK" rel="nofollow noreferrer">https:&#x2F;&#x2F;www.flightaware.com&#x2F;live&#x2F;flight&#x2F;SWA2340&#x2F;history&#x2F;2023...</a>

Is this for connecting to a home device without paying for wifi?

Fun fact: ZeroTier works in most cases on in-flight wifi without logging in. I guess they usually allow UDP.

I did something similar on an easyJet flight, I wrote a little Python script to save the altitude and speed data from the free WiFi. They have a cool 3D WebGL rendering of the plane in the air like Flight Simulator, but the satellite imagery was really low res.

Sometimes the budget airlines don&#x27;t fly to where I&#x27;m going, or do so by long multi connecting routes.  I&#x27;m currently sitting on an AA flight because it was the cheapest option with a reasonable travel time.  Honestly, it kind of sucks for all the usual reasons, but I&#x27;ve at least got free wifi on my phone through some deal with T-Mobile.

&gt; I don&#x27;t see why anyone would fly United, Southwest, American Airlines, etc VS.the budget Airlines like Spirit.I&#x27;m on a spoke (not a hub) and just don&#x27;t have the service available to use budget airlines even if I wanted to. We have JetBlue -- they fly to Boston and that&#x27;s it. We have Allegiant and they fly to Phoenix (not really Phoenix -- Mesa), and we have Avelo they they fly to LA (not really LA: Burbank). All these airlines fly one flight per day, and often not every day of the week. When I&#x27;m traveling somewhere that works for the budget airlines, I&#x27;m still leery because if their plane breaks down or there is &quot;weather in Cincinnati&quot;, I&#x27;m screwed. They don&#x27;t have a second plane available.otoh we have United, Delta, American, Alaska, Southwest with flights to several hubs each, multiple flights per day, through international ticketing, first class sometimes open... Plus I don&#x27;t pay for luggage on the major carriers due to credit card membership&#x2F;status.

Did you have a negative view of Spirit before flying with them?Not sure about my backside.. don&#x27;t do squats lol ... 5&#x27;10 170

You must have buns of steel. I flew Spirit exactly once (well, twice, it was round-trip), and it was such a miserable experience I swore to never do it again. Their seats are made of concrete as far as I can tell.For domestic flights I pretty much always sit in the window and never get up during the flight. On spirit I had to get up and walk around after about 3 hours &#x27;cause my ass was sore. Never again.

Just to clarify, Southwest is classified as a budget airline, especially compared to the &quot;big 3&quot;. Spirit and airlines like them are in their own class called ULCC (ultra low cost carrier) to differentiate them from the existing budget airlines.

Sure for me I fly out of a major hub (Baltimore Washington International) and Spirit flies pretty much to every US city from there.One thing bad about spirit is their extremely horrible refund policy .. their seats are a bit smaller but not by much.Thus far in my ten recent experiences flying Spirit with clothes &amp; travel necessities in my book bag has saved me lots of money and my flight experiences have been the same to even better compared to Dekta, United, Alaska or Southwest. Thus the first place I now go to book a flight is spirit due to my experiences and flying out of a major hub.I hope JetBlue doesn&#x27;t get the chance to buy them out ... Spirit allows a lot of ppl who couldnt afford to fly enjoy a benefit all should be able too and for me i like saving money!

If you travel lite with clothes in a book bag(wash clothes if extended stay)… I don&#x27;t see why anyone would fly United, Southwest, American Airlines, etc VS.the budget Airlines like Spirit.Maybe if you have points with those airlines… Otherwise, save hundreds of dollars using budget airlines which the planes are newer in my experience, and never had a bad experience versus my recent bad experiences with Delta and the others in which I paid a lot more for. Almost all airlines I&#x27;ve had to pay for Internet access, including Spirit so for me, I don&#x27;t understand why I would fly all the more expensive airlines versus using Spirit.There&#x27;s a lot of negative marketing out there about Spirit… After my 10 positive flights experiences in the last six months with them I don&#x27;t believe the hype.

&gt; amazing engineeringBackground updates are a built-in, supported, documented feature, widely employed by applications on the platform, and accessible to anyone that reads the two pages of documentation required to use them:“Pushing background updates to your App — Deliver notifications that wake your app and update it in the background.”<a href="https:&#x2F;&#x2F;developer.apple.com&#x2F;documentation&#x2F;usernotifications&#x2F;setting_up_a_remote_notification_server&#x2F;pushing_background_updates_to_your_app" rel="nofollow noreferrer">https:&#x2F;&#x2F;developer.apple.com&#x2F;documentation&#x2F;usernotifications&#x2F;...</a>edited for politeness

You&#x27;re not understanding the point of the comment. The Flighty team did some amazing engineering work for anyone who doesn&#x27;t pay.

Sure. But you’re on a site called “Hacker News”. I’m not sure that there’s a more perfect topic of discussion for a site with that name.

This seems like a poor slippery slope argument. It’s not as if charging for internet is new, it’s been what? 20 years? And yet they still don’t charge for water

Tomorrow it&#x27;ll be 8 bucks to drink water, 8 bucks to use the bathroom, ...Yeah, you can argue internet isn&#x27;t a necessity. Neither is the bathroom, you can use a poo bag and a diaper. But we&#x27;re a civilized society. So we provide bathrooms to anyone that needs them. And internet access.

If you really think the folks here do this to save a few bucks, you both 1) don&#x27;t realize what the average pay of people here is, and 2) are completely tone- and context-deaf.Look at the domain name of the site you&#x27;re posting on and read it out loud. FFS dude. LOL

We detached this subthread from <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=37691621">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=37691621</a>.

It is just 8 bucks for the full service... just buy the internet bro. It is actually pretty good.

Love the spirit of this article. The author could have Git-scraped [0] this info!<a href="https:&#x2F;&#x2F;simonwillison.net&#x2F;2020&#x2F;Oct&#x2F;9&#x2F;git-scraping&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;simonwillison.net&#x2F;2020&#x2F;Oct&#x2F;9&#x2F;git-scraping&#x2F;</a>

I tried to change the flight level by PATCHing altitude, but it seemed to require authentication. Oh well.

Someone will probably figure out how to send a request to disable auto-pilot or turn off the fasten seat belt sign.

Please stand by, a DHS agent will be with you shortly

You probably can. I suspect airliner software is appallingly insecure.

It would be nice if you could send a POST request to open the door if you want some fresh air.

Thanks! I was trying to figure this out but I didn&#x27;t have great Internet access (for some reason...) so I just hacked it instead.

In powershell<pre><code> Invoke-WebRequest https:&#x2F;&#x2F;wifi.delta.com&#x2F;api&#x2F;flight-data | ConvertFrom-Json | %{ &quot;https:&#x2F;&#x2F;maps.google.com&#x2F;?q=$($_.latitude),$($_.longitude)&quot;</code></pre>

You can use jq&#x27;s string interpolation feature to simplify this:<pre><code> $ curl -s https:&#x2F;&#x2F;wifi.delta.com&#x2F;api&#x2F;flight-data | jq -r &#x27;&quot;https:&#x2F;&#x2F;maps.google.com&#x2F;?q=\(.latitude),\(.longitude)&quot;&#x27;</code></pre>

I doubt Delta made this. It’s an official the shelf product that can do ships, trains, planes, etc.

Interesting how they chose to make more general `vehicleId` instead of `planeId` or `tailNumber` or something. I wonder if Delta&#x27;s fleet includes other things that have matching APIs to this one. I also wonder how much of their internal system structure one could learn from the `flightId` if they knew about other systems. It doesn&#x27;t look like much beyond a composite key of otherwise knowable data, but still interesting.

That’s just a sampling error. -NaN is when you get scared.

&gt; &quot;airspeed&quot;: null[nervously looks out window]

As always, there&#x27;s a relevant XKCD:<a href="https:&#x2F;&#x2F;xkcd.com&#x2F;2170&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;xkcd.com&#x2F;2170&#x2F;</a>

I assume the DNS server on the in-flight router is programmed to resolve that hostname to some local device.Similar to how I can log into my ASUS router from my home wifi by visiting asusrouter.com.

What makes it so that you can only resolve the host wifi.delta.com during a flight?

I have nothing insightful to add, I just want to say thanks for posting this!I’m on a flight right now and just went to this URL. Sure enough, it works!I know this information is available via the wifi portal’s UI, but a JSON blob just hits different.```{&quot;timestamp&quot;:&quot;2023-09-28T21:57:39Z&quot;,&quot;eta&quot;:&quot;23:45&quot;,&quot;flightDuration&quot;:164,&quot;flightNumber&quot;:&quot;DAL992&quot;,&quot;latitude&quot;:47.4557876586914,&quot;longitude&quot;:-111.73490905761719,&quot;noseId&quot;:&quot;3883&quot;,&quot;paState&quot;:false,&quot;vehicleId&quot;:&quot;N883DN&quot;,&quot;destination&quot;:&quot;KMSP&quot;,&quot;origin&quot;:&quot;KSEA&quot;,&quot;flightId&quot;:&quot;N883DN_SF_20230928195737&quot;,&quot;airspeed&quot;:null,&quot;airTemperature&quot;:null,&quot;altitude&quot;:35273,&quot;distanceToGo&quot;:13,&quot;doorState&quot;:&quot;Closed&quot;,&quot;groundspeed&quot;:499,&quot;heading&quot;:95,&quot;timeToGo&quot;:107,&quot;wheelWeightState&quot;:&quot;Off&quot;}```Apologies for the JSON formatting, I’m on mobile.

It&#x27;d be interested to make a little HTML page that can query the api for each airline that exposes something like this and give you an in-flight display on your laptop.

Here is how to get the equivalent data on a Delta flight.<pre><code> $ curl https:&#x2F;&#x2F;wifi.delta.com&#x2F;api&#x2F;flight-data | jq
 % Total % Received % Xferd Average Speed Time Time Time Current
 Dload Upload Total Spent Left Speed
 100 448 100 448 0 0 5600 0 --:--:-- --:--:-- --:--:-- 5743
 {
 &quot;timestamp&quot;: &quot;2023-07-11T14:54:41Z&quot;,
 &quot;eta&quot;: &quot;17:48&quot;,
 &quot;flightDuration&quot;: 278,
 &quot;flightNumber&quot;: &quot;DAL786&quot;,
 &quot;latitude&quot;: 39.723472595214844,
 &quot;longitude&quot;: -97.1514205932617,
 &quot;noseId&quot;: &quot;3879&quot;,
 &quot;paState&quot;: false,
 &quot;vehicleId&quot;: &quot;N879DN&quot;,
 &quot;destination&quot;: &quot;KPDX&quot;,
 &quot;origin&quot;: &quot;KATL&quot;,
 &quot;flightId&quot;: &quot;N879DN_SF_20230711121358&quot;,
 &quot;airspeed&quot;: null,
 &quot;airTemperature&quot;: 24,
 &quot;altitude&quot;: 33922,
 &quot;distanceToGo&quot;: 179,
 &quot;doorState&quot;: &quot;Closed&quot;,
 &quot;groundspeed&quot;: 442,
 &quot;heading&quot;: -73,
 &quot;timeToGo&quot;: 174,
 &quot;wheelWeightState&quot;: &quot;Off&quot;
 }
</code></pre>
And a fun snippet for you.<pre><code> $ curl -s https:&#x2F;&#x2F;wifi.delta.com&#x2F;api&#x2F;flight-data | jq -r &#x27;&quot;https:&#x2F;&#x2F;maps.google.com&#x2F;?q=&quot;, .latitude, &quot;,&quot;, .longitude&#x27; | tr -d &#x27;\n&#x27;; echo
 https:&#x2F;&#x2F;maps.google.com&#x2F;?q=40.5615234375,-101.2824478149414</code></pre>

I&#x27;ve done something similar on trains in the UK before, specifically LNER (was Virgin Trains East Coast at the time but don&#x27;t think the Wi-Fi solution has changed) trains. The icomera captive portal has an endpoint which returns the GPS coordinates of the train along with the speed. And some other endpoints for next stops etc.Once made a little React app that showed the train on a Leaflet map. Was a good waste of a few hours.

I have an American Airlines flight in a few hours. Looking forward to see what kind of data I can find now

Hackers talk about ethics and legality all the time!

Are you aware what the website you&#x27;re currently on is called?

&gt; That said, I&#x27;m curious what risks you have in mind.Overzealous prosecutors.

No permission - just curiosity :)I&#x27;m not too concerned about the risk associated with fetching a JSON file that their flight status page is already fetching on a loop. That said, I&#x27;m curious what risks you have in mind.

Cybersecurity and internet crime laws are notoriously outdated (created in the 80s). I could see a bad lawyer arguing that cURLing an API repeatedly is “hacking”.

There&#x27;s no &quot;probing the network&quot; involved here.The in-flight webpage was continuously fetching a specific end-point from the in-flight web server.This end-point is basically public data.All he did was duplicate what the webpage was already doing, and then do some basic analysis on the data the end-point was returning.

Does one generally require permission to read a sign that someone else posts in a public place?

The signal is already reaching your computer. You are not modifying it. It is the same as listening to radio.

Did you have permission to do that ? Sounds pretty risky to be probing the network of a flight imo.

Can&#x27;t you create an SSH tunnel to a machine and RDP with it? Then you&#x27;d have fully functioning internet.

On many United flights you can connect to onboard wifi without buying the plan and have internet access on port 22 and apparently unrestricted UDP.  This allows me to connect to an EC2 instance running mosh.  Coding in vim is a great way to pass the time on a flight.

Reminds me how old and unsecure those system used to be, years ago they would perform DNS queries but block most traffic, meaning that you could get free internet by using DNS tunneling.Same for the movies on board, if they have some apps and not just movies in front seat, you can use vlc, ffmpeg to download &#x2F; watch the movie without ads &#x2F; interruption.When I was doing some digging they used a lot of Panasonic solution and open source stuff such as squid cache, apache http.<a href="https:&#x2F;&#x2F;na.panasonic.com&#x2F;ca&#x2F;industries&#x2F;avionics" rel="nofollow noreferrer">https:&#x2F;&#x2F;na.panasonic.com&#x2F;ca&#x2F;industries&#x2F;avionics</a>

I used chart.js [0], but I don&#x27;t necessarily endorse it - it&#x27;s just what I knew how to use quickly. I usually try to keep my posts free from javascript, and could have used a different tool that gives me SVG data or images.You can see the code that&#x27;s generating these charts here: <a href="https:&#x2F;&#x2F;github.com&#x2F;jamesbvaughan&#x2F;jamesbvaughan.com&#x2F;blob&#x2F;main&#x2F;content&#x2F;posts&#x2F;southwest-wifi&#x2F;charts.js">https:&#x2F;&#x2F;github.com&#x2F;jamesbvaughan&#x2F;jamesbvaughan.com&#x2F;blob&#x2F;main...</a>[0] <a href="https:&#x2F;&#x2F;www.chartjs.org&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;www.chartjs.org&#x2F;</a>

What did you use to create your graphics?

this is such a wholesome nerd post.  i love it.

Maybe the plane is staying level but the ground is variable terrain.

20-30 feet change over what timeframe? The resolution of the chart data in the article is about 30 seconds. While I think the fluctuation is due to the accuracy of instrumentation, 20-30 feet change over the course of a minute seems like nothing.

Planes report pressure altitude via their transponders. 20-30 feet up and down is very normal for an autopilot.GPS altitude is used for vertical guidance for certain types of GPS approaches (i.e. &quot;LPV&quot; approaches[1]) and requires the airplane&#x27;s avionics to be equipped with a WAAS[2] receiver that provides accurate altitude information.[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Localizer_performance_with_vertical_guidance" rel="nofollow noreferrer">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Localizer_performance_with_ver...</a>[2] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Wide_Area_Augmentation_System" rel="nofollow noreferrer">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Wide_Area_Augmentation_System</a>

When you take off, you&#x27;re going up at a rate of 500 fpm to 2000 fpm. Even if you go from +1000 fpm to -1000 fpm over the course of several seconds, you aren&#x27;t going to feel much.At cruise altitude, you&#x27;re moving along at 500 mph, which is 777 feet per second. So going from +30 feet to -30 feet in a minute is just an adjustment of only about 5 degrees. You&#x27;d barely feel it, even walking down the isle. An acceleration of 33 ft&#x2F;sec per sec is 1 g.You experience greater changes in vertical motion on any flight you go on.*edit: units

A plane going up and down 20-30 feet seems like it would be very unpleasant. Considering that there&#x27;s longitude and latitude, isn&#x27;t it more likely that the altitude is coming from GPS, which is notoriously inaccurate with regards to elevation?

It was probably fairly precise already. To get their license, a private pilot must demonstrate via a checkride the ability to stay within 100 feet of an assigned altitude, even in a steep turn.

I guess they got a lot more precise with implementation of Reduced Vertical Separation Minimum (RVSM) - planes had to be separated by 2000 ft and this was reduced in early 2000s to 1000ft

I went down a rabbit hole by clicking on globe.adsbexchange.com :)

Pressure encoders, as I said. That&#x27;s what feeds all aviation altitude data... i.e. anytime you see the word &#x27;altitude&#x27; and its not qualified with &#x27;GPS altitude&#x27; which is effectively not normally used. ADS-B Out concurrently transmits GPS height about the ellipsoid data as well as pressure altitude data. No use is normally made of the GPS height data. We are discussing pressure altitude data here, that&#x27;s what aviation works off of. The accuracy and reliability metrics in the ADS-B broadcast you are referencing refers to the GPS data not the pressure transducer&#x2F;encoder data. In cases of encoder failure being detected a flag is broadcast and the pressure aka baro altitude data field is set to all 0. ADS-B cannot give information about the pressure altitude accuracy or reliability like it does for GPS metrics. It relies on the encoders being better than their +&#x2F;- 125&#x27; accuracy requirement and that&#x27;s tested for periodically. ADS-B can in principle broadcast 100&#x27; or 25&#x27; resolution encoders, that info is in the messages. The ones here will be 25&#x27;. (I&#x27;ve got a long background with ADS-B related technology, currently helping the FAA out on some niche stuff).edit: trying to improve clarity&#x2F;correctness but there is too much to cover here.

I don&#x27;t know what sensors are feeding the API from the post, but most passenger jets do broadcast information about the accuracy of their sensed position, including vertical position&#x2F;altitude. If you click on an aircraft on the map at <a href="https:&#x2F;&#x2F;globe.adsbexchange.com&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;globe.adsbexchange.com&#x2F;</a>, and scroll the left sidebar all the way to the bottom you&#x27;ll see a section labeled &quot;Accuracy&quot;. ADS-B Exchange doesn&#x27;t show Rc&#x2F;v, the vertical position accuracy, but it does show other values. See <a href="https:&#x2F;&#x2F;mode-s.org&#x2F;decode&#x2F;content&#x2F;ads-b&#x2F;7-uncertainty.html" rel="nofollow noreferrer">https:&#x2F;&#x2F;mode-s.org&#x2F;decode&#x2F;content&#x2F;ads-b&#x2F;7-uncertainty.html</a> for more information.

No idea how true it is, but I overheard someone on a flight say that whenever you feel a real sudden jolt on a plan it&#x27;s really only moving like 2-3ft.

Yes, it&#x27;s called the navigation paradox, and it mostly came about with the advent of GPS. It&#x27;s the reason we now have what&#x27;s called &quot;strategic lateral offset procedure,&quot; or SLOP, whereby aircraft on heavily trafficked oceanic routes fly zero, one, or two miles off the centerline, randomly chosen.

how is it any better when 2 opposite planes choose same 2950ft?

I have read somewhere that so much precision could actually be dangerous in some circumstances.This is because this way, if a pilot goes 3000 ft for instance, it will be exactly 3000 ft, if another pilot also wants to go 3000 ft on a collision trajectory, it will be a guaranteed collision. When altitudes are not that accurate, there is a higher chance it being just a near miss. The solution, I think, was to simply avoid round numbers. So now, it is 2950 ft, 3050 ft,...I may have the details wrong, but I am quite sure about that problem being seriously considered.

For small planes a 20-30 foot range isn’t abnormal for hand flying if you’re paying attention. I’m sure in cruise an airliner is using an autopilot though.I once had ATC ask if everything was cool on flight following after a hundred foot drop and I was surprised they were paying that much attention. I had forgotten to put my life jacket on before a water transit and while I was putting it on handed it off to my wife who hadn’t taken lessons yet (she later got her license!). It was interesting to see that their tracking was precise enough for them to chime in.

When I am on a flight and the flight does not provide the flight information, I am using the OsmAnd, <a href="https:&#x2F;&#x2F;osmand.net&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;osmand.net&#x2F;</a>, to monitor the flight altitude, speed and direction.

You use standard pressure (29.92 inHg) above transition altitude, which, in the United States, is 18,000 feet. Pilots wouldn&#x27;t be changing the altimeter after climbing past this point, and would start using local values once descending through it again.Of course, your initial point is still correct: there could be slight variations if using those local settings and getting different values, but you&#x27;d only see that below transition altitude.

At high altitude you do this stuff &quot;When you set your altimeter to 29.92, you&#x27;re flying at standard pressure altitude.&quot;The idea is all the planes use the same setting so the one at FL35 doesn&#x27;t hit the one at FL36. But those are not exactly 35000 and 36000 feet above sea level.

The QHN&#x2F;Kollsman window setting only affects what is displayed to the wetware. When you strip away all that the autopilot is just servoing to a pressure altitude. But sure if you are flying below the transition altitude and are flying between areas with different QNH settings when you adjust the setting the autopilot will climb or descend as needed because you told it to servo to a different pressure altitude.There are many EFB (e.g. Foreflight), or log book, or other flight recorders you can use on an iPhone. And some can record the pressure transducer in the iPhone to record an approximate &quot;pressure altitude&quot;. e.g. Naviter SeeYou Navigator intended for gliders can do that (but it&#x27;s not unusual for modern gliders to have an array of sophisticated air data sensors and specialized variometers and flight computers that would feed the app this data over Bluetooth). Popular EFB software Foreflight will not use the iPhone pressure transducer, if you want pressure data there you need to drive that through an external interface like a Sentry ADS-B receiver that has a pressure sensor built into it -- or much better if the aircraft is equipped with ADS-B Out can receive the &quot;own-ship&quot; ADS-B Out broadcast pressure altitude from it&#x27;s high accuracy encoder). Any in-cabin pressure traducer will be sensitive to the difference between calibrated static pressure and cockpit pressure, things like opening or closing vents, or varying the airspeed significant (and ram air pressure or suction on the cockpit exit vents) can cause observable changes. And when using an iPhone or similar, especially without a great GPS satellite overhead view (e.g. in high wing aircraft) you are likely not to get high-quality GPS altitude data. think best case ~ +&#x2F;- hundred feet, worse case with little overhead GPS sat view, much worse... but those consumer GPS app is likely to happily display multiple decimal points of precision :-)

&gt;&gt; Autopilots are very good and they are servoing to the pressure altitude.It would have been cool to use a phone to record a GPS track with altitude and compare them. Pressure != GPS. Also wonder if there would be distinct jumps in the difference if they reset the pressure based altimeter to a different AWOS.Not sure how it works in big planes, but in little ones you need to set your altimeter based on the local weather. The weather stations measure barometric pressure at their elevation and &quot;correct it to sea level&quot; you get this corrected reading over the radio and set it in your altimeter so your pressure-based altitude reading is corrected for local weather variations. Just going out flying for an hour the altimeter setting when returning to the same place might be off by a few millibar.

What kind of telemetry (protocol, topology, etc) is used here? I&#x27;m in utilities, so am used to seeing modbus, DNP, etc, but also some OPC-UA nowdays.

“According to this data, the plane’s altitude was only fluctuating by about 20-30 feet. This is more stable than I expected!”Autopilots are very good and they are servoing to the pressure altitude.Many pressure altitude encoders used in modern aircraft (for example to drive altitudes that transponders report to SSR radar or via ADS-B) have 25 ft encoding resolution. That 25ft resolution is likely what is being seen here. Other encoders have 10 ft resolution but 25 ft is very common.

Ah, interesting. I guess this could be used by UnifiedNLP: <a href="https:&#x2F;&#x2F;f-droid.org&#x2F;en&#x2F;packages&#x2F;de.sorunome.unifiednlp.trains&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;f-droid.org&#x2F;en&#x2F;packages&#x2F;de.sorunome.unifiednlp.train...</a>Also, KDE Itinerary: <a href="https:&#x2F;&#x2F;invent.kde.org&#x2F;pim&#x2F;itinerary&#x2F;-&#x2F;blob&#x2F;master&#x2F;src&#x2F;app&#x2F;SettingsPage.qml#L194" rel="nofollow noreferrer">https:&#x2F;&#x2F;invent.kde.org&#x2F;pim&#x2F;itinerary&#x2F;-&#x2F;blob&#x2F;master&#x2F;src&#x2F;app&#x2F;S...</a>I&#x27;m off pinging the relevant projects :)

Plus there&#x27;s no Internet. What&#x27;re you going to do, read a book?

Yep, that&#x27;s exactly right! They have a nice status page that you can visit free of charge that visualizes this data.I chose to scrape it for a couple reasons:1. I wanted see all of the data for the entire flight - that status page only visualizes the current values.2. It was fun!

I was on some US flight recently - maybe Alaskan airlines - and they basically had a LAN box with movies and shows accessible on wifi without internet access

Thank you. That answers the question I had which was, &quot;why does trying to get the portal page return a load of data about the plane?&quot;

But SouthWest will give you a much prettier display of that same data (track your flight, see the current altitude and ETA, and a lot more, like the plane&#x27;s position on the map) without paying for their WiFi. My guess is that they are using the same data that article writer wrote a program to process. Essentially there is one site you can visit for free and that&#x27;s where it is.

The complaint is collecting data on others. Specifically the complaint is on others collecting data on me.

&gt; I didn’t know what I’d do with the data at this point, but I started collecting it right away so that I’d have as much as possible to play with later.And people complain that everything everywhere collects data on everyone.

I have a similar program I run that does this stuff for United flights:
<a href="https:&#x2F;&#x2F;github.com&#x2F;ejcx&#x2F;uwc&#x2F;blob&#x2F;master&#x2F;uwc.go">https:&#x2F;&#x2F;github.com&#x2F;ejcx&#x2F;uwc&#x2F;blob&#x2F;master&#x2F;uwc.go</a>The code is horrendous but it has worked for years and I guess when I wrote it originally I didn&#x27;t want to use a go struct for some reason?

Talking to the pilots costs about $200 and is really easy, though very illegal - just find out which ATC freq are they currently on and transmit, from a handheld radio or a HackRF. You could also transmit on Guard.If you prefer to text rather than speak you can send them ACARS, with roughly the same hardware. Though if you use a handheld radio you&#x27;ll also need a laptop to generate the baseband signal, as I don&#x27;t think there are any commercially available ACARS transmitters.(Please never do this, you&#x27;ll go to jail for a long time).

I usually connect to the cockpit directly with rj45 to keep it stable. Sometimes even talk to the pilot with the encrypted coms.

Wait, doesn&#x27;t everybody set up a prometheus&#x2F;grafana dashboard for each flight to show the telemetry?

WiFi without internet on a Southwest flight