svirfnebli

Older wifi hot spots assumed that most people were using the Hotspot for Web based traffic which is routed through tcp port 80. Lazy programmers blocked port 80 without authenticated login (paid access) but left all other ports open. For example smtp email on port 23. Often messaging software and streaming services use different ports other than port 80 or the secure port 443 which would explain why you can access those services while being connected but without being authenticated. Try it at hotels too.

Lani1

Sprint works fine throughout flight if you want to text

AirbusFan2B

This has happened to me several times while flying at cruising altitude ORD-HNL and ORD-SFO and vice-versa. I figured it was due to proximity to a tower near the continental divide.

mr8

Noticed this last year too!
Not sure if it works on all flights, but do remember having iMessages on some international flights like the discontinued flight from NRT-SIN and several domestic flights within the US.

I was even able to access google flights on a couple of flights.

mickowit

Once in a blue moon when connected the the inflight app for entertainment (unpaid access to WiFi), I can also send and receive iMessages. Any rhyme or reason to it? It seems to be random and not something done on demand. Tips? Tricks?

MBS MillionMiler

Been doing this for a while, myself! It's only iMessage. Frankly, I've found it to always work--it hasn't been random for me, as you describe...But I also don't take Gogo-serviced flights very often--so that might be the issue.

Tblack15

Yes, I've been doing this as well. Kind of goofy, also funny that it may be a gap in the wifi technology that allows iMessage. So instead of patching it, DL offers it "as a service"? May not be the same provider or technology, but funny to think that.

Kmxu

IMessage worked for me recently (without paying for wifi). I guess that UA has not announced it yet. They want to give flyers a small friendly surprise.

ryman554

Once a captive wifi provider provides *some* access to the internet, particulaly for some "partner sites", access to the internet writ large is likely to be "leaky".

What you are seeing is a consequence of that. It may or may not be on purpose.

flyerbaby19

I've never been so lucky. Wish I could recreate.

escapefromphl

Yeah so they are obviously not blocking port 5223, https://support.apple.com/en-in/HT202944 I wonder what else they don't block.

t325

I was with a buddy of mine on a 737-900 last week and he was able to iMessage during the flight without paying for WiFi.

Southwest's WiFi is pretty leaky too. I'm an Android user, and have received hockey score updates in Google Now without paying for WiFi. I've also noticed I can browse and search the Google Play Music library, but not actually stream anything - if I try to play a song I don't have downloaded for offline use, it will go as far as to get the album art and metadata, just no actual music. Which still renders it useless.

My theory is that phones detect whether or not they're on a captive portal by trying to access a page on either Apple or Google's server. If they get the expected page, it assumes you're on a regular network and it never asks you to sign into the portal, otherwise it displays the portal page for you to log in. So my guess is that they've opened up access to some domains or IPs belonging to Apple and Google to fool phones into thinking it's a regular WiFi network without a captive portal, so it won't keep prompting you to log in while watching movies via PDE. Some other Apple and Google services just happen to use those same servers or IPs so they still work and can't be blocked. United and Southwest keep it quiet, while Delta advertises this "bug" as a free service.

Hipplewm

iMessage has worked for quite some time

fezzington

It's mainly the 737 fleet where this is possible. Mostly the -800s and -900s (It didn't work for me the last time I was on the -700).

I forget which (if any) widebodies it works on.

tarheelnj

Seems to work for me on DirecTV-enabled planes.