Even less than a 150 years ago that would have been impossible. And prior to that communication among normal people could take months.
Even less than a 150 years ago that would have been impossible. And prior to that communication among normal people could take months.
Unreliable certainly. For as long as there’s radio coverage there’s a way, but it used to be impractical to give passengers enough bandwidth. 20 years ago you’d have to ask the captain nicely to get a call routed (read: have an emergency)
If you allow civilian HAM radio, you go back a few more decades (not quite applicable to planes, but definitely applicable to boats). If you allow Morse code you go back yet a little further.