Other than that, GPS is a one-way system, it does not know you exist, how fast your receiver is moving or "give" different information to one client vs another.

Even if it did, this is essentially a toy and moving slower and lower than a general aviation plane.

It uses accelerometers and other sensors because they can be sampled and integrated hundreds of times a second. The $5 gps module is 9600 baud serial and provides one update/second (or maybe 5/sec depending on which part number you pick).

The original USB mouse (for the first iMac) was round, so you couldn't orient it in your hand without looking at it constantly.

And it came with a very short cord (because there was a port on the right side of the keyboard to plug it into). But then the laptops got updated with USB ports and they were only on the LEFT side of the case.

For at least a year or two you could not buy an Apple mouse for your Apple PowerBook and use it in your right hand, because the cord was too short to go around the case.

Eventually they shipped a "Pro" mouse with revolutionary elongated shape and longer cord. (...and optical tracking, and what looked like zero buttons, which were pretty neat)

This info is in the automated weather broadcast (ATIS) audio for any towered airport.

Most large airports provide a textual version (D-ATIS), so suitably equipped pilots don't have to listen to it and scribble it down.

E.g. Heathrow now from random unofficial website: https://atis.guru/atis/EGLL

EGLL ARR ATIS T 1820Z LANDING RWY 27L…

EGLL DEP ATIS U 1427Z PILOTS ARE EXPECTED TO CHANGE TO RWY 27R AT AT 15:00 HOURS… DEPARTURE RWY 27L…

For powered flying, one a week is already on the low end... most instructors would recommend 2-3x/week.

Flying skills are very perishable, especially when first learning. This is why there are several different rules about recency of experience before you can do things like carry passengers, recurrent training requirements, etc.

Group all resolutions returned that are the same +-5% together and choose the lowest one in the desired bucket.

But we're comparing to SpaceX launches. Plenty of Raptor engines have blown up on the ground too.

There were 13 Saturn V's launched and all of them basically performed their mission (Apollo 6 being a bit of an exception) with 0 rapid unplanned disassemblies...

https://www.williams-sonoma.com/products/bedford-sofa-uphols...

Personally I'd rather buy one from IKEA and use the change left over from $12k to buy.. a used truck to drive the sofa home in.. but apparently there's a market.

You can certainly go much higher for smaller companies producing actual custom stuff, using exotic materials, for a giant sectional instead of a single sofa, etc.

newfstatat(AT_FDCWD, ".", {st_mode=S_IFDIR|0700, st_size=4096, ...}, 0) = 0

newfstatat(AT_FDCWD, "/usr/local/sbin/cat", 0x7fffcec2f3b8, 0) = -1 ENOENT (No such file or directory)

newfstatat(AT_FDCWD, "/usr/local/bin/cat", 0x7fffcec2f3b8, 0) = -1 ENOENT (No such file or directory)

newfstatat(AT_FDCWD, "/usr/sbin/cat", 0x7fffcec2f3b8, 0) = -1 ENOENT (No such file or directory)

newfstatat(AT_FDCWD, "/usr/bin/cat", {st_mode=S_IFREG|0755, st_size=68536, ...}, 0) = 0

> Except as prohibited in [unmanned aircraft section], each person operating an aircraft equipped with ADS-B Out must operate this equipment in the transmit mode at all times unless [authorized by FAA or ATC].

A common way to add ADSB to an aircraft not originally equipped is replacing one of the lights with a uAvionics skyBeacon[2], which has a LED light + ADSB-out transmitter. So the nav light switch would control it, but you'd also now be required to have them on at all times.

[1]: https://www.ecfr.gov/current/title-14/part-91/section-91.225...

[2]: https://uavionix.com/products/skybeacon/

The timeframe could be anything, but common forms are like:

- Within the next X (flight) hours or Y calendar days

- You don't have to, but additional inspection needed every X hours or Y days until you do

- At next annual inspection

- Immediate/before flying again (usually called an Emergency AD)

It was well before most other protocols were worrying about the security or privacy of being intercepted at all. Decades before TLS by-default-because-why-not started becoming a thing (largely because of LetsEncrypt). Especially for an app that was mostly for pirating stuff. Your email and it's login/passwords, IRC, instant messaging, regular browsing, etc all happened in plain text.

And despite the physical networks being super vulnerable back then. Ethernet was mostly connected by hubs/ring/shared coax, so every device received every other's packets. WiFi was just coming around and is a shared medium. Several rounds of inept security schemes failed to even keep people who don't know the network password from intercepting nearby traffic. Most networks didn't have security on yet anyway.

The Hotline protocol was/is mostly binary messages sent over TCP with a 4 character text message type followed by a corresponding packed data structure of the related data. (https://hotline.fandom.com/wiki/Protocol#Session_Initializat...)

But there are tons of flying general aviation planes that are from the 50s/60's, and a long tail going back even further than that. Some of them don't even have a radio to talk on. Or an electrical system to run it.

Mandating ADSB took many years, and still has exceptions carved out. And that's a fairly simple technology. There are companies that build it all into a replacement tail light LED "bulb" to provide compliance for ~$2000.

Still that might be 5-10% of the value of your 1977 Cessna 152. If you take the cheap airframes out of the sky, that makes new pilots getting their 1500 hours more expensive before they can go get a job on the big boy planes.

There have also been trials done with "virtual towers" at smaller airports, using a bunch of cameras and with controllers remotely monitoring them and communicating.

So first we need more training capacity, and they already have trouble hiring and retaining instructors. This is a more direct place you can throw more money at now.

A start would be moving some of the primary training to the control centers. There's more than one of them, spread around the country, and they already have their own significant training departments.

A significant fraction of people who get into the academy end up not making the cut. Then another good fraction "wash out" during extensive training for the specific airport/center they end up in.

It's a very difficult job and nothing they've tried before is very good at predicting who's going to be successful at it quickly/cheaply.

That doesn't matter much over Washington DC, but when you get out towards the western half of the country the transmitters are a lot more widely spread out. There's mountains in the way. There's limitations to how low you can be and still be reachable, which sometimes has to be balanced against how high a GA plane can comfortably fly, or oxygen requirements for the occupants.

A better sounding "modern" system is generally going to be worse at handling those marginal situations, which would probably require building a lot more radio outposts in fairly remote areas to compensate.

But the big problem with requiring anything new is getting it into the existing fleet of thousands of decades old certified aircraft. You need a new radio stack. You probably need new antennas. Changing anything on certified aircraft needs tons of paperwork and things like Supplemental Type Certificates for each individual model of aircraft that make it cost 5-50x what you'd think it should cost. Military aircraft are probably 10x worse beyond that.

A handheld COM radio is maybe $200 from Sporty's. Take basically the same thing but package it as a basic Garmin COM radio (GTR 205) and it's now $2,300. If you want a NAV radio in it too (GNC 215) now it's $5,400. Add GPS and ADSB-Out (GNX 375) and now you're at $9,000. You can buy an entire currently airworthy (really old) plane for maybe $30,000.

For some uses you don't even have to have any radio or transponder/ADSB installed on your aircraft. Some aircraft don't even have an electrical power system to run one. Granted they're not allowed in the middle of Washington DC, but still trying to require the entire fleet gets fancy new digital radios would be a monumental challenge and fantastically expensive.

There are some existing better ways to communicate. Larger planes usually have CPDLC (Controller Pilot Data Link Communications), which is basically text messaging from ATC to the plane avionics. That's how they receive their IFR clearance at major airports. In an airliner you're not generally reading it out over the radio and scribbling out your "CRAFT" acronym on a scratchpad like you see on YouTube. (Even your 4-seat steam gauge Cessna can do this via PDC (Pre-Departure Clearance) at supported airports with something like ForeFlight on an iPad).

CPDLC can also be used in the air to communicate less time-sensitive things like altitude changes and reroutes, talking to the operations department of the airline, etc. There's no reason you couldn't put this in smaller GA planes and towers, other than cost.

Airliners that do transatlantic and -pacific routes also have satellite communications instead of using old-school HF radios (which are even worse than VHF).

The "tower" controller manages the actual runways, and the airspace within several miles of the airport laterally and a few thousand feet vertically (varying at each airport). This includes sequencing all the planes that want to take off of land there, and everybody maneuvering around that immediate area.

For the large airports that mostly big airliner flights, that sequencing is largely worked out by the approach controllers dozens or hundreds of miles ahead of time. So there's a steady stream of planes following standardized approach procedures at just the right distance apart.

Outside of the ~30 busiest airports in the country though, there is also a lot of general aviation in small planes. They want to transition through that airspace, or do a dozen laps around the "pattern" to practice landings, etc. Even at fairly major airports, there's plenty of GA activity. For example at Burbank, Ontario, John Wayne, Long Beach, San Jose, Oakland, etc in California. It's only really SFO and LAX where that doesn't really happen, because they set fees to shoo the peons away.

SQL is a small but very busy airport that is almost exclusively GA. There are several flight schools there with multiple planes each, and it's sandwiched in complicated airspace between SFO, SJC, OAK, and open bay.

The tower at this kind of airport is doing a delicate dance keeping multiple planes buzzing around in a rectangular pattern all day every day. Some of which are faster than others. Less frequently a larger much faster plane wants to get in or out and they're getting handed off from approach. Helicopters are doing tours and wanting to cross through. And a lot of the people flying are students that are new at this, don't know how to talk or listen on the radio right yet, make mistakes following directions, etc.

With the tower closed, all those people have to coordinate on a party-line radio with each other about where they are, what they're doing, etc to hopefully not hit anyone. So yeah... it's possible, but it's going to be a mess, and that's why tiny airports like this with virtually no commercial passenger service have a tower.

Also if you're leaving the immediate area, someone at the airport (ground, tower, or "clearance delivery", depending) normally will coordinate putting your destination (for visual/VFR flight following) or full route (for IFR/instruemnt) into the ATC systems before you takeoff so that you can talk to the approach controllers once you leave and they can provide you traffic advisories, etc.

With nobody at the tower to do that, you have to "cold call" approach once already airborne. Or if your route allows, just not get flight following at all (and then ATC has no way to reach you). So SQL tower closing will also add to the workload for the SFO/OAK approach area.