For EU flights especially you still check passports at the gate - indeed it's the only place they are checked.
For other flights they normally check visas at the checkin desk, but if you're transferring you usually get visa checked at the gate. Most people have nice simple visas that pretty much anyone can check, a few troublemakers like me rely on more complex timatic rules (say TWOV in Beijing on multiple tickets), but no reason that can't be checked at gate either.
Which countries? I fly a lot NL<>ES, ES<>DE and they don't check my passport usually. I do take it because sometimes they ask for it, but mostly they don't.
The UK obviously being the outlier; very paranoid with extremely old scanners so security takes a long time, especially at Heathrow.
I don't believe they run any inter-schengen or other "domestic" flights, and the 5th freedom flights they do run are like Singapore to Sydney so attract passport viewing.
Security is irelevent to BA's problems.
Airlines like Ryanair do check photo ID on domestic, but that's for revenue purposes (to stop people selling tickets on the black market)
The Police do have far-reaching powers under the fascist "Schedule 7" of the terrorism act 2000 to demand ID of some sort in certain circumstances, but that's not unique to flying.
You don't realise how much IT is involved in the process of loading a plane. Just the weight and balance calculation will take a very long time if done manually.
"BA said it is reverting to manual systems for check-in at airports."
The problem is that the manual process is slower and once a flight gets too delayed then it misses its slot and if too many flights get delayed it causes cascading problems since there aren't enough free later slots to put them in and you have to cancel.
If BA put aircraft in the air without any idea who was on them, they’d be rapidly forced to land again with the threat of being shot down.
I was waiting in the lounge as it kept being delayed further and further, with the standard 'go to gate' message. Unfortunately they were also slow at updating the status and it went seamlessly into 'gate closed'. I ran to the gate, but was too late. The staff there seemed surprised that they'd missed me - they weren't even aware they were missing a passenger.
The fun then started trying to get my bag back. Copenhagen airport made me wait around for hours for my bag to arrive at the designated unloading carousel, and wouldn't open a missing bag ticket. Eventually they had to concede it had gone missing somewhere after I found the baggage handler who'd unloaded some bags from my flight saying he hadn't unloaded mine. They still wouldn't admit it had flown ahead of me, even as a possibility.
When I then got to Helsinki on the next flight, I went to the counter and told them they had my bag. Again they told me there was no possibility they had it, and wouldn't even look. So I gave them my ticket number and left. They found my bag shortly after I left, of course.
Not in the US...
Even back in the 90s - just a few years after Lockerbie - we had some UK guests staying with us. We flew from Detroit to Vegas for a few days. They're luggage got put on a different plane, and ended up in LA. They were horrified and couldn't figure out why their luggage was on a flight they weren't on.
Doesn't seem to be a big concern in the US, as I've had my own luggage get on wrong flights at least twice in the past 5 years, and I don't actually fly all that much (2-3 flights a year max).
> let anyone onboard with […] sufficient story about buying one
> some people might get a free ride
As dagw’s comment points out they’re using the pen and paper approach; however, it takes longer and missed slots/out of place crews can cascade catastrophically.
It is far easier to fly to Switzerland than to the UK.
If someone does not board; their luggage is removed from the hold for security reasons. To do so, safely, would require so much communication between flight and ground staff, that I'm not sure either staff would know how to begin without the middle-ware.
That's insane - that'd never happen. There's no way they can take that security and immigration risk. I bet they can't even do that if they want to - I'm sure governments need to know all travellers precisely.
The gate staff should just let anyone onboard with a legit ticket or a sufficient story about buying one.
Sure, some people might get a free ride, or a few legit ticket holders can't get on because the plane is full, but overall, most passengers end up happy.
Simple things like "the pilot can't log in to the HR system so he gets paid for the flight" should be fixed with a combination of process changes and "let's just fly now, make paper records, and fix the computer records later"
Communication systems should have a backup of a large box of walkie-talkies in every airport so that, for example, the baggage staff can radio to the pilot to let him know they are done loading.