It's really sort of the opposite. You don't see 727s or MD-80s at the terminal anymore (freight somewhat excepted). Airliners are used constantly, wear out and get replaced/sent to other countries. Buying another computer is a negligible cost in a new 787 or retrofit into anything an airline currently flies.
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.
A lot of them don't. They work in nondescript windowless buildings controlling all the airspace that isn't right above an airport.
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.
And as far as I can tell, representations are still projected on a 2D screen. Air traffic using 3d projections might lower the technical bar for controllers? VR + AI seems inevitable.
The first problem is that everybody who wants to do the job needs to go through the FAA academy in Oklahoma, which is seriously limited by physical & instructor capacity. So only a couple thousand people a year can work their way through there, no matter how many are willing to do the job.
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.
This has been a snowballing problem since Reagan fired 11,000 controllers for striking in 1981... so sort of, but not the one you're thinking of, and there's been plenty of both sides of the aisle doing nothing to solve the problem in the meantime.
Realistically, because standing up a new academy isn't fast, and everyone wants fast solutions and won't invest long term. That isn't a party line thing, both parties have that issue.
Besides the "we already have it everywhere" bit, the big advantage of analog AM over UHF/VHF is that it degrades fairly gracefully. As you're getting too far away the signal gets harder to pick out from the noise, but it's not an all-or-nothing digital signal.
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 "ground" controller manages taxing around the "movement areas" (i.e. taxiways) on the ground. This notably does not include the runways. And it depends how much of the actual ramp and parking area they control (those are sometimes non-movement area and it's the pilots job to not hit anything).
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.
It is somewhat surprisingly (still) a $500m+ revenue[1] company, with very minimal employees and expenses. They're printing money on house and car listing fees.
The two solid rocket booster casings are dropped into the ocean and (usually) recovered with both the Shuttle and SLS.
RS-25s were the three main engines. They were very expensive, designed for reuse and were recovered with the rest of the orbiter they were bolted on to. Not in the ocean. Then refurbished with a much greater amount of effort and money than initially expected, and eventually reused on a future mission..
But the SLS first stage doesn't fly itself back to Cape Canaveral after 2 weeks like the Shuttle orbiter did. So those now FOUR very expensive "reusable" engines are now chucked into the ocean never to be seen again.
Simply having to maintain one or more ships (continuous expense, year round, year after year), to fish those tubes out of the ocean (once every few years) almost certainly ate up any cost savings they could possibly get from refurbing the tubes.
Lmao, do you have any idea how much ships cost? The spent SRBs being sunk are the least of SLS's problems. SRB shell refurbishment had dubious economic sense when Shuttle was flying several times a year, but for something that will fly as few times as SLS it would be an absolute farce.
Airplane autopilots follow a lateral & sometimes vertical path through the sky prescribed by the pilot(s). They are good at doing that. This does increase safety, because it frees up the pilot(s) from having to carefully maintain a straight 3d line through the sky for hours at a time.
But they do not listen to ATC. They do not know where other planes are. They do not keep themselves away from other planes. Or the ground. Or a flock of birds. They do not handle emergencies. They make only the most basic control-loop decisions about the control surface and power (if even autothrottle equipped, otherwise that's still the meatbag's job) changes needed to follow the magenta line drawn by the pilot given a very small set of input data (position, airspeed, current control positions, etc).
The next nearest airplane is typically at least 3 miles laterally and/or 500' vertically away, because the errors allowed with all these components are measured in hundreds of feet.
None of this is even remotely comparable to a car using a dozen cameras (or lidar) to make real-time decisions to drive itself around imperfect public streets full of erratic drivers and other pedestrians a few feet away.
What it is a lot like is what Tesla actually sells (despite the marketing name). Yes it's "flying" the plane, but you're still responsible for making sure it's doing the right thing, the right way, and not and not going to hit anything or kill anybody.
Thank you for this. The number of people conflating Tesla's Autopilot with an airliner's autopilot, and expecting that use and policies and situations surrounding the two should be directly comparable, is staggering. You'd think people would be better at critical thinking with this, but... here we are.
Ah. Few people realize how dumb aircraft autopilots really are. Even the fanciest ones just follow a series of waypoints.
There is one exception - Garmin Safe Return. That's strictly an emergency system. If it activates, the plane is squawking emergency to ATC and and demanding that airspace and a runway be cleared for it.[1] This has been available since 2019 and does not seem to have yet been activated in an emergency.
It does do that and it's pretty neat, if you have one of the very few modern turboprops or small jets that have G3000s & auto throttle to support it.
Airliners don't have this, but they have a 2nd pilot. A real-world activation needs a single-pilot operation where they're incapacitated, in one of the maybe few hundred nice-but-not-too-nice private planes it's equipped in, and a passenger is there to push it.
But this is all still largely using the current magenta line AP system, and that's how it's verifiable and certifiable. There's still no cameras or vision or AI deciding things, there are a few new bits of relatively simple standalone steps combined to get a good result.
- Pick a new magenta line to an airport (like pressing NRST Enter Enter if you have filtering set to only suitable fields)
- Pick a vertical path that intersects with the runway (Load a straight-in visual approach from the database)
- Ensure that line doesn't hit anything in the terrain/obstacle database. (Terrain warning system has all this info, not sure how it changes the plan if there is a conflict. This is probably the hardest part, with an actual decision to make).
- Look up the tower frequency in DB and broadcast messages. As you said it's telling and not asking/listening.
- Other humans know to get out of the way because this IS what's going to happen. This is normal, an emergency aircraft gets whatever it wants.
- Standard AP and autothrottle flies the newly prescribed path.
- The radio altimeter lets it know when to flare.
- Wheel weight sensors let it know to apply the brakes.
- The airport helps people out and tows the plane away, because it doesn't know how to taxi.
There's also "auto glide" on the more accessible G3x suite for planes that aren't necessarily $3m+. That will do most of the same stuff and get you almost, but not all the way, to the ground in front of a runway automatically.
I think it will also activate if the pilot is unconscious, for solo flights. It has something like a driver alertness detection system that will alarm if the pilot does nothing for too long. The pilot can reset the alarm, but if they do nothing, the auto return system takes over and lands the plane someplace.
Yes those are optional systems that exist, but they are unrelated to the autopilot (in at least the vast majority of avionics).
They are warning systems that humans respond to. For a TCAS RA the first thing you're doing is disengaging the autopilot.
If you tell the autopilot to fly straight into the path of a mountain, it will happily comply and kill you while the ground proximity warnings blare.
Humans make the decisions in planes. Autopilots are a useful but very basic tool, much more akin to cruise control in a 1998 Civic than a self-driving Tesla/Waymo/erc.
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.