Yet another Hacker News

Show HN: Live map of U.S. flights during tonight's FAA nationwide ground stop

75 points gvsi 5 hours ago 10 comments

cobychapple 3 hours ago | parent

Fun irony (beyond being Friday the 13th): FAA lost radar and frequencies between centers but ADS-B is broadcast by the planes themselves, so a couple hundred hobbyist receivers probably kept the full picture the whole time.

monkeymeister 3 hours ago | parent

Wow, impressive TTM. Barely enough time for the domain to resolve!

gruez 3 hours ago | parent

>Barely enough time for the domain to resolve!

contrary to popular belief, DNS doesn't actually need 24 hours (or whatever) to "propagate". It only needs enough time for caches to expire, if they exist. For non-existent domains this shouldn't be an issue.

gnabgib 3 hours ago | parent

DNS controls the length of time an answer is valid (with time-to-live/TTL), some (poorly configured, but for a historical good reason) caching servers ignore the TTL and keep the record much longer (~24 hours).

A non-existent (not yet resolvable) domain, will get an NXDOMAIN response which also gets cached via a TTL setting (which again might be ignored by caching servers).

All that caching - while the current response is still "valid" because the TTL hasn't expired - is what people call "propagation".

halamadrid 3 hours ago | parent

Really fast work! I didn't know all of this data was publicly available.

gvsi 2 hours ago | parent

I remember seeing a similar cool GIF for 9/11 flights, and thought it'd be cool to see if for today's ground stop too, and had Claude Code generate the website in ~30 mins.

Liked it so much and thought I'd clean it up a bit, deploy, and share :) Enjoy!

thirtygeo 2 hours ago | parent

Everyone I shared this with while stuck in transit today loved it. Thanks for inspiring some good vibes in Montreal!

bmfischer3 2 hours ago | parent

What’s underlying data source for it all?

gvsi 1 hour ago | parent

Flight positions: adsb.fi community ADS-B network. Airport delay feed: FAA NAS Status

ChrisArchitect 1 hour ago | parent

FAA issues national ground stop

https://news.ycombinator.com/item?id=50489641

FAA lifted National Ground Stop at 0119Z

https://news.ycombinator.com/item?id=50492601