Due to the the time it takes at either end, there's a fixed minimum time cost to flying. Maybe three or four hours counting both ends.
If I'm taking a 6 hour flight, it's actually a 10 hour flight. If the airplane gets there twice as fast, it's a 7 hour chunk of my time. I save three hours but how much am I willing to pay for that? It's still effectively a calendar day gone.
For shorter flights, this is even worse. For super long flights like London to Sydney, maybe it would be useful to double the speed, so that you're not wasting two days instead of one, but doubling speed is also pretty far from possible.
There is a point in getting faster. The Concorde run profitably for the later 20 years of it's lifetime. At its best it did the New York to London route in under 3 hours. At more than double the speed of a subsonic flight. I have taken multiple 7 hour and 3 and a half hour flights and I would pay a significant premium to cut the 7 hours in half. It's not that I would have more of the day available. It's that I would spend less time in the plane. Being in a plane for a long haul is miserable. In the nineties if flew profitably for a 10% markup over regular business class.
I would wager a supersonic jet liner could make a lot of money crossing the Atlantic or the Pacific even today. Sure for short hauls it makes no sense.
Btw, Boom is working on supersonic private jets,they recently flew a scaled down experimental jet at supersonic speeds.
Concorde’s problem was once the lie flat business seat was invented in 2000, it was substantially more comfortable than what was, by all accounts, a plush but very narrow seat due to the narrow fuselage.
Throw in the third flight crew member and the economics fell apart.
I think with how unergonomic airplane seats have gotten, there's a real health benefit to minimizing the time people are crammed in those cramped seats.
If they made airline seats reasonably sized and ergonomic, sure, the flight time matters less, but right now the longer the flight portion is, the longer my back will complain afterwards. I'm not even unusually tall or heavy-set.
Airlines won't make the seats bigger since that would cut into margins, but if the planes are faster, they can run more flights and pay the pilots/flight-attendants for fewer hours, so that feels like it's a solution that's more likely to happen than the real solution, of making it so the seats aren't designed to destroy your back until you pony up for business/first class.
One of the reasons I don't travel as much is due to this.
I used to live in the peninsula in SFBA. I was about 20-30 minutes away from SFO. Unless it was an international flight or I had checked luggage, I would never get to the airport before the flight started boarding. I would walk through security at a lightning pace (SFO is one of those airports where sometimes TSA precheck is longer than regular!) and get to my flight just as my boarding group was getting called.
It was so insanely efficient. I never spent a moment not moving in the airport. I'd often spend more time waiting on the plane to deboard than I would in the airport when leaving too.
I miss SFO. I live in NYC for now and all the NYC airports suck for the fact they all take about an hour to get to (from Manhattan) and they all regularly have large and inefficient security lines with theater that is only rivaled by Belgian airports.
I worked for someone once (pre-9/11) who would do the go to airport 30 minutes before flight sort of thing. Absolutely hated it. Airport was close to downtown Boston but still not how I like to catch planes even if delays are rarely an issue.
When I lived in Kyiv and airports were still a thing, flying from Zhuliany was a bliss. Something like 30 minutes from the apartment door to sitting at the gate. The fact that it's small and in city limits was a deciding factor.
Boryspil' is twice the distance from the city center (whatever you pick for city center in Kyiv) and is quite nice and modern airport with all the problems of a big modern airport -- it's huge, lines are long and unpredictable and it doubles as a mall.
IMHO we would be better served reducing the amount of time it takes you to go into an airport and board a flight. Right now they recommend 2 hours prior to takeoff but if you're in the right airport and know what you're doing then that time could be as little as 30 minutes (or less).
Rather than trying to take time out of the "middle" of the journey (ie when you're on a plane), we would be better served as a society to take time out of the "ends" (before takeoff and after landing).
But nevertheless I still think it's worthwhile for us as a species to look at ways we can cross the planet faster. I think eventually (maybe in our lifetimes), the idea of taking a flight that takes you into outer space won't be too far fetched. While I don't think the time savings going supersonic will be worth it, I think the savings when going into outer space will, assuming we figure out a economical way to get people up and down from outer space.
> But nevertheless I still think it's worthwhile for us as a species to look at ways we can cross the planet faster. I think eventually (maybe in our lifetimes), the idea of taking a flight that takes you into outer space won't be too far fetched. While I don't think the time savings going supersonic will be worth it, I think the savings when going into outer space will, assuming we figure out a economical way to get people up and down from outer space.
It's possible that it may make sense to establish a few business class only very fast point-to-point routes. But that also really depends on the vehicle taking people through space. There are a number of problems:
1. Currently, spacecraft are only licensed for experimental travel. Everyone signs an informed consent waiver and basically disclaims all liability. And the FAA is forbidden to regulate for passenger safety by congress (and has been for quite a long time) - they can only regulate for the safety of the general public.
This would have to be changed before any serious commercial spacecraft went into service
2. It's not clear that any spacecraft has the economics to pull this off. Maybe Starship can do it. But it's pretty far from clear that they can.
3. Spacecraft are orders of magnitude less safe than commercial aviation. Do you know the saying "regulations are written in blood"? If this starts happening, there'll be a lot of new regulations that happen over time.
And maybe that'll happen anyhow - I think that space tourism will certainly be a thing that becomes much more popular in the future, and that has the exact same problems (although it's much less readily comparable to commercial aviation).
Yeah I totally agree with your points. If space travel ever becomes commonplace it won't be anytime soon, my gut says it would be "in the next 100 years".
Seriously. Just have the whole passenger section setup like cargo pallets and wheel them in and out of the plane. Why bother walking up and down a narrow aisle? Just have a "passenger marshalling facility" away from the airport, have the interior section in parts there, have everyone comfortably load up, put that on a bus, wheel that straight to the plane, then load them in like large scale cargo through a huge side door.
Lock them down and send them wherever. Do the same in reverse at the destination.
Each one has to be a pressure vessel, so either we have a bunch more pressure doors on the plane, or each one has its own toilet, galley and staff. Sounds expensive.
But the limiting factor isn't whether you're in the airport, it's whether you can arrive at the airport with that much a time margin reliably. It does not take many traffic accidents or an unexpected rail disruption to mean you miss your flight, for example - the 2 hour window is essentially to force people to account for unexpected delays.
Having faster flights could also increase the frequency of such flights, which lowers the impact of a missed flight, which lets people be more loose with getting there early enough.
>the idea of taking a flight that takes you into outer space won't be too far fetched.
Reading this unlocked memories of the (after googling it) September 2005 National Geographic Kids magazine, which was centered around future life in 2035. One of the things in it was exactly this: travel time cut by launching into orbit and flying around the planet to cut travel time down to ~1h.
For most people, reducing the pre-checking time would require full refunds if they can't make it in time for some reason. This is especially true if the airport isn't even in the same city.
It's particularly cheap in around Melbourne because the government introduced a daily fare cap across the whole state. So it's $10 from Melbourne to the state border, then the other $25 is for the much shorter trip from the border to Canberra.
It's absurd that getting onto a 3-dimensional bus takes ~1.5hr more per end than a normal bus. The fundamentals of embarking and disembarking passengers and their luggage is unchanged beyond needing to have all the luggage in a pile before you toss it on for weight distribution reasons.
You can't remove the part where you have to travel to an airport, generally out of town.
Security also seems to be variable enough that you need to add buffer, and then there's the built in incentive to have people sitting around in a shopping mall.
This has always confused me because it seems like it seems like the easiest possible prediction problem. Nearly everyone buys their tickets in advance, often weeks ahead of time.
Why can’t they text you the day before and say “The airport will be quiet/normal/chaotic for your flight tomorrow, so please arrive 1/2/3 hours before takeoff?”
I wouldn’t change the flight itself, but I’d certainly use it to decide when I set out for the airport. Not by a ton but it’s easily the difference between a leisurely farewell breakfast and scarfing down a muffin on the run.
can bring a quart zip lock bag stuffed to brim with nips (50ml bottles of booze) through TSA security. While you are technically not allowed to drink them on the plane absolutely nobody gives a shit as long as you are not an idiot about it.
bingo! for long-haul flights (>10hrs) i'd even bring two zip locks. Relax and fall asleep right during takeoff while everyone else has to wait for the stupid cart forever.
And you can also bring an empty water bottle that there are often stations setup for the purpose of filling next to water fountains.
Mind you, I'm annoyed at the liquids thing given I used to routinely bring bottles of wine or a local liqueur home in carry-on. And I can't any longer.
I recall when those guys in the UK (?) had their plan to explode a plane by mixing some volatile chemicals in the plane toilet. IIRC this kicked off the whole no liquids requirements. At the time I remember reading an article by a chemist on the chances of actually pulling off what they wee planning to do, and it was comical. To not just make a giant poof that mainly singed off some hair they needed to carefully mix the liquids in an ice bath for about 1h (without anyone noticing) and every little shake could potentially mess up the whole thing.
He then went on to what he considered dangerous and mentioned a couple of powders which you can easily bring on board which are much more devastating.
>He then went on to what he considered dangerous and mentioned a couple of powders which you can easily bring on board which are much more devastating.
So this is why we also can't bring own cocaine on board in addition to not having own booze. What a shame
I think the point of it was that our enemies had figured out that the way to destroy America wasn't to kill our leaders, but rather to convince us that our enemies were inside the country, and then watch us tear each other apart.
I really wish we had strict SLAs for airport security. Like 10 minutes average 20 minutes for the 95% percentile and a guarantee that it will never exceed 30 minutes. Seeing lines form around the block and passengers having to wait hours to clear security in some extreme cases is simply not acceptable.
It isn't, but changes that require additional staffing simply aren't going to be tolerated. If you add more staff, that directly translates to higher ticket prices because passengers directly pay for most of the TSA costs. If you expand facilities, that takes away from the valuable real estate the airport would rather use to sell you magazines and duty free. It also harms their Clear revenue stream, who pays airports to make security lines worse as a means to convince people to sign up.
Or we could streamline the process: remove steps that are taking too long for little benefit (typically asking people to remove their shoes) and automate more.
>> I really wish we had strict SLAs for airport security.
What they should really have is a line for clueless people. You know, the people ahead of you who walk thru metal detectors with belts. Then aw-shucks and waste another 5minutes. Then they forgot to take their laptops out of their bag. Aw-shucks again. Then they want to unlace their shoes.
I'd love to have a line for clued-in travelers and one for people who arent.
If only it was only a belt. I've had multiple times where I was behind someone with a concealed firearm that tried to walk through security who somehow "forgot" they had it. One time it seemed the person was on probation as well and shouldn't have even had access to firearms!
> You can't remove the part where you have to travel to an airport, generally out of town.
Some airports have good connections. In the last month I've been to Berlin and Brussels, and in each case my train journey into the city was about 15-20 minutes (caveat: I happened to be going to the right side of Berlin for the airport, and the Brussels train, while central, was _bizarrely_ expensive).
Of course, some airports, not so much. Grumble mutter Dublin (there is some hope of a rail line, or possibly _two_ rail lines, in about 2040, but until then it's a choice of painfully slow standard buses (1 hour into city), or expensive unreliable express buses (25 mins into city, if they show up)).
But for many routes, really security, and the sheer poor layout of the airport, is the big slowdown. My favourite for this is London City; the (small, weird) plane lands, you walk out a door, and you are at a DLR stop.
Boarding also always takes far longer than you'd imagine it should, mostly due to people being people. In principle you could board an airliner in a couple of minutes, but only with perfect behaviour from all passengers, so good luck with that.
> Boarding also always takes far longer than you'd imagine it should
There was a company about 15 years ago that developed a double ended jetway so you could load and unload from the front and back simultaneously. They said it shaved about 18 minutes from loading and unloading (combined). On the average flight this would be the equivalent of going about 100mph faster for seemingly a simple change.
They installed a few in Denver and I believe in Calgary. Unfortunately one in Denver had a problem and collapsed and hit the wing of a plane, and so they ripped them all out and no one ever tried again.
Ryanair loads its planes from both ends in most airports (except in airports where they're required to use a jetway). It _helps_ (I was recently on a Ryanair flight from Brussels, a mandatory-jetway airport, and it was noticeably slower than usual to load) but it's still a lot slower than you'd hope.
Ryanair actually orders specialised 737s with built-in airstairs and a few other modifications to facilitate this.
This only really works for 737-sized planes and down, though, where air-stairs are an easy option (AFAIK even A320s can be a bit of a stretch, as they're significantly taller than 737s).
Yeah I've done that on a few euro airlines. It's definitely faster to load, but usually you have to take a bus to the plane, which adds a lot of time and hassle that you don't have with a gate. I still really think that the double ended gate is probably the lowest hanging fruit in terms of speeding up air travel. The only reason I can think of that we don't have it is that you can pay more to be at the front of the plane, so a lot of the benefit goes to the lowest paying passengers. I would still think that this would improve the turn around time for the airplane so that the airline could get more utilization, but perhaps loading/unloading is not the critical path anymore in turning around the airplane.
> It's definitely faster to load, but usually you have to take a bus to the plane, which adds a lot of time and hassle that you don't have with a gate.
Ah, that depends on the airport. Haven’t been on one of those in a few years; I think Ryanair and friends managed to grab a lot more proper gate space during Covid when the higher-end airlines were practically giving it away.
(Years ago, I was on a Ryanair flight to Brussels airport which used a jet bridge, because it’s mandatory there… But the jet bridge was in the middle of nowhere, served by a bus. Half-convinced Ryanair does this sort of thing deliberately, to live up to their brand image of being quite annoying.)
> but perhaps loading/unloading is not the critical path anymore in turning around the airplane.
It _definitely_ is, at least for short-haul stuff.
> But for many routes, really security, and the sheer poor layout of the airport, is the big slowdown
Washington Dulles aka IAD is a fine example. It has a vast security area below deck for regular folks and a smaller one up top where all the Clear and Pre flyers go. That should be inverted.
Then, after security, passengers must walk 300m and change levels to catch a small shuttle train. Or, to take the special mobile lounge bus things. If you take the train, it drops you off 500m from the gate area, so you have tonget off the train, climb the stairs, walk through a tunnel, climb the escalator, and then walk the remainder of the terminal to your gate. It is absolutely laughable how poor Dulles is, esp considering its importance to United.
> Boarding also always takes far longer than you'd imagine it should, mostly due to people being people. In principle you could board an airliner in a couple of minutes, but only with perfect behaviour from all passengers, so good luck with that.
I don't know why there isn't just a bunch of seats in the terminal laid out the same way as the plane. Sit there and wait, and then when it's time to board, the people at the end get on first, tada, everyone is boarded and we're not stopping each other from getting in.
It's because the overhead space is limited. Airlines have spent decades trashing, losing, and delaying checked luggage, so everyone tries to cram everything into the overheads. Since there's never enough room for everyone to do that, higher classes have to board first so they can. It would be nice if first class could at least be at the back so the line didn't completely stall in reverse order, but they also want to get out (the front) first, and you will never convince the other passengers to wait for that.
Or you're traveling to an airport near the city from out of town. For me it's over an hour and the associated cost--rarely drive myself--is often as much as the flight.
Security doesn’t have to be that variable. Flights are all planned weeks in advance. TSA can pretty exactly predict the passenger volume in time to schedule enough workers, it’s just that sometimes they don’t. If they were going to be short staffed and needed people to come early, they could notify the airline and the airline could notify you that you needed to come early that day.
Denver's airport is apart from the actual city, and there are light rail lines connecting it with downtown. That system... does not work very well, owing to crappy light rail and the fact that most people still aren't where they need to be even if they took that to Union Station.
If you're suggesting this hypothetical giant tunnel would actually have the planes taxiing all the way to a whole airport underneath a city... I don't see that solving more problems than it would create.
You have airports that are pretty convenient to the city (assuming that's where you're going). Boston. SFO is at least on BART. The old Hong Kong airport. But newer airports tend to be pretty far out because they presumably need more land and that land isn't available near the city.
So as a reader one can assume that either a) I forgot about the wings (I guess I must be an idiot) or b) I am using a broader set of reference objects than simply "current passenger transportation modes". There are many man made objects much bigger than airplane wings. Fitting an aircraft carrier, or a container ship, or a skyscraper, moving under a city, would be much, much harder than fitting an airplane. Not to mention that if we strongly applied this engineering constraint, it's not beyond the realm of imagination that we could produce airliners with removable or foldable wings, or where the passenger compartment slides out, or tunnels with deep grooves for the wings, etc.
It's not. There are "air routes." Your plane will be delayed if they are too busy or cannot be sequenced into arrivals from the route at an appropriate rate. This happens flying into JFK and a fair amount flying out of it.
Landing and takeoffs put the plane within seconds of domestic infrastructure below. It's even more controlled.
Your pilot is considering all of this, plus weather deviations, along the entire journey and at the destination, before you even leave. Your '3d bus' doesn't actually exist unless you're flying private VFR. Then, and pretty much only then, can you get out there and just "fly around."
Finally your "2d bus" can just stop. It can literally just stop and do nothing. Your plane cannot without significantly implicating your life.
IF (yes, still a reasonably big IF) they could just automate highway driving, a large segment of air trips become really a wash, especially if you consider that taking your car someplace gets you a car for your destination, while if you flew it is an additional hassle/expense/delay.
So the exercise to me is: how far does it have to be before you would rather fly? If I had reliable highway automated driving, you're already dealing with a 3-4 hour drive being reasonably equivalent to the time and hassle of a 1 hour flight.
Plus with a car you can leave on a whim with no prescheduling, pack more with less restrictions, will be cheaper generally (especially if carpooling/family driving), can stop and eat more conveniently, have better internet access typically, can stop and see friends or other places along the way, and again, you have your car for transport when you get there.
A self-driving sprinter van converted to an RV would be even better: sleep overnight, have a place to stay at a minimum when you get there.
Anyway, I suspect this might hollow out quite a lot of flight demand when it becomes a reality (any decade now). Airlines will be forced to reexamine their policies if an overnight self-driving trip gets you the vast majority of the way to a destination.
My wife and I really don't start regretting our 18 our drives to and from Florida until the last couple hours. The kids sleep for more than half of the trip and the air travel experience is just a whole other kind of exhaustion.
Plush buses are still buses - you will need to rent a car or take a ride at the end to get where you are going. A self-driving car that takes you from door to door? Yeah, that's completely different.
You live in Pittsburgh. You want to go to NYC for a show. You hop in the car, it takes you to the theater, you get out, it drives itself to a parking lot in NJ to wait. You call for it half an hour before you need it, it picks you up, and it drives you home. That's currently the province of the very rich or the very extravagant. A car that drives itself can do that every night.
Yeah, I take a bus trip regularly between cities for work. It's ~3.5 hrs from downtown to downtown and, even though the flight would only be just over an hour and about the same price, it ends up being not worth the effort.
Some high speed trains (in Spain, for one) require security checks to board as well. But they're way less intrusive or time consuming than flight checks.
> Due to the the time it takes at either end, there's a fixed minimum time cost to flying. Maybe three or four hours counting both ends.
To be fair to airports, the arrival side hasn't really changed post 9/11. If you check bags, that's on you - it's going to be slow to get your stuff.
But yeah - having to budget time to get through security is a pretty poor user experience. Especially during busy times of the year, when it's more uncertain just how much time is required.
I don’t understand why people act like checking bags is a huge time sink. It’s maybe fifteen minutes at most on a bad day for the bag drop, and I can’t remember the last time I had to wait more than 20 minutes for them to show up on the carousel at my destination (and 20 minutes is super slow, it’s usually more like 10). The only times I’ve really had problems with checking bags is connecting flights when my flight is delayed or canceled and such, and even then while there was some stress over it my bags always got to my destination either when I did or sooner. On the last point the last time I flew international I had a baggage attendant at Heathrow actually call my phone personally to reassure me they had my bag and told me where to go to pick it up when I got to baggage claim.
I’m sure there’s horror stories out there of course, there always is, but 99.99% of the time checking a bag is only marginally less convenient than trying to fit everything in my carryon.
I’ve had a vastly different experience. Several trips in the last year with 30 minutes+ to drop a bag and a couple closer to an hour. That’s enough to move the needle on when I feel like I can show up to the airport.
Baggage claim is usually pretty quick but even 5-10 minutes sucks after flying.
I’ve also had 2 bags fail to make it with my plane meaning I had to wait 24 hours for a courier to deliver them. It also makes connecting or flight changes much more dicey.
I definitely think I’ve been unlucky recently but the fact that I could be unlucky is why I avoid it as much as possible
There are times when I know I have to check a, usually, pretty small bag. But especially because of the delayed baggage issue or because of last minute changes to flights because of weather or whatever, I probably carry-on (with a light load) 9 times out of 10. Especially with dress being more casual these days I usually don't really need more than carry-on unless I'm activities requiring some amount of gear.
The thing that kind of sucks is that picking up your bags is before customs, where another line can develop, so that 15-minute delay can lead to an hour+ in line if a bunch of airplanes unloaded all at once.
> To be fair to airports, the arrival side hasn't really changed post 9/11. If you check bags, that's on you - it's going to be slow to get your stuff.
Except it has changed in the last couple of decades (probably not due to 9/11, but still), because size and weight limits for hand luggage keep getting smaller and smaller. I have always travelled light and avoided checking in luggage except for very long stays abroad, but it's becoming increasingly difficult.
For example, both Qatar and Etihad (very common airlines to travel between Europe and Asia) now limit hand luggage to 7 kg (and in the case of Etihad, they don't even allow the typical "personal item"). 7 kg is laughably little, a standard cabin bag already weighs 2. Pack a laptop and you'll struggle to pack even summer clothes for a few days. Let alone winter clothes or -oh, the luxury!- buying some souvenirs at your destination.
Fortunately, in my experience, they mostly just don't look. But they could, if you're unlucky. And even if they don't, the dwindling limits also reduce practical slack, i.e. with a formal limit of 9 kg I would feel comfortable packing 10 or 11 because most airport staff probably wouldn't be strict about that, but with 7, packing 10 or 11 starts looking like a real gamble.
I'll admit that I don't travel outside of the US much, so those issues don't really apply to me.
> 7 kg is laughably little, a standard cabin bag already weighs 2
One thing that I have done is move from roller luggage to a travel backpack. I personally use the Osprey Farpoint, but there are many in the category to choose from. Not only is it much lighter than hard sided luggage, but it's typically much more forgiving of dimensional requirements, and can often fit in overhead bins, where hard sided luggage may not be able to (if you're the last person trying to put something in the bin).
And on top of all of that, it's been much more reliable for me - I've had and seen roller luggage fail pretty often - at both the wheels and the handle. Neither of those exists on the bag, which just keeps trucking.
I get that for many people a travel backpack isn't an option. But if it is something that might work for you, I highly recommend it.
Worth considering to be honest, as I'm in reasonable shape so carrying a backpack is not out of the question.
But do you think one can pack as much as in roller luggage, while conforming to the size limits? I've always been under the impression that roller luggage would be more efficient in this respect, but have no real experience traveling with a backpack.
IMO, backpacks are better at conforming to size limits.
They're typically advertised by volume, so 30L, 40L, etc., so you can get one the size you want. I think carry on size is typically advertised as 35-40L. They've got all the same stuff as roller luggage - straps, dividers, etc., depending on what you want. Although, IMO, the best setup is to just get a bag with the volume you want and use packing cubes.
The great advantage of backpacks is that they're soft. Every carrier has their own "box" that your item is supposed to fit into. As long as you don't have too much stuff, you can just squeeze your bag into the box. But with a hard sided roller, it either fits or it doesn't.
Fully agree. Even if it's not completely soft, a 40L-ish travel backpack is just about perfect for most trips unless you just physically can't carry.
I do have a larger travel pack and sometimes favor a slightly larger wheeled pack. But even though it's a bit heavy for any really long schlepping, it's lighter than the wheeled frame and is a lot easier to deal with on trains etc.
Roll-a-boards are the devil IMO but then I'm not usually dressing up when traveling. I tend to use a probably somewhat larger 40L Osprey than what you use but it's a lot more flexible than the standard carry-ons to put in overhead.
It’s kind of insane how no profiling is allowed whatsoever.
Has a plane ever been hijacked by a couple of European descent traveling with their own children? The lengths we go to to pretend everyone is the same is mind boggling.
> She claimed to be unaware of the contents, and that she had been given the bag by her fiancé, Nezar Hindawi, a Jordanian.
Certain groups perform attacks of this kind.
It's not necessarily because they are backwards or evil or something. They just can't resist militarily, so they go for soft targets.
If the situation was reversed, and there was some kind of hegemonic global Islamic caliphate with an ostensibly unbeatable military, perhaps you would get some random Poles or Spaniards blowing up planes.
People who aren't in groups in those kinds of situations, don't do things like that. Why would they? Why do we pretend that they would?
The thing is that being, for example, Arabic looking or having an Arabic sounding name isn't a prerequisite for being Muslim. So if we started profiling for people that we thought were Muslim, then it would be pretty easy for terrorists to figure out our criteria and just use the most "white-seeming" of their cohort to commit attacks.
If, on the other hand, you randomly select people for additional checking, they can't predict that and can't learn how to circumvent it, they just have to take a stab at an attack and hope they don't get unlucky.
Basically, any deterministic aspect of security is predictable, which makes it vulnerable.
Due to the the time it takes at either end, there's a fixed minimum time cost to flying. Maybe three or four hours counting both ends.
If I'm taking a 6 hour flight, it's actually a 10 hour flight. If the airplane gets there twice as fast, it's a 7 hour chunk of my time. I save three hours but how much am I willing to pay for that? It's still effectively a calendar day gone.
For shorter flights, this is even worse. For super long flights like London to Sydney, maybe it would be useful to double the speed, so that you're not wasting two days instead of one, but doubling speed is also pretty far from possible.