In the case of aviation it was aircraft and then after a while we got ATS, no aircraft - no ATS, no ATS - no...... well actually there would still be aircraft but ops in many ways would be severely reduced, so it is without a doubt an essential service but not a prerequisite for flight.
True. When the early mail runs got caught in IMC, they'd close the fuel, switch off the mags and jump over the side. When the fog lifted next day, they'd hunt for the wreakage, salvage the mail and get on their way.
Fancy trying that today?
