Can you share data source for 1B? This seems like it's 1-2 orders of magnitude off based on gut feel and I'd like to understand how I can be this far off.
"That’s the revenue that British Airways generated each year linking its London Heathrow hub and New York John F. Kennedy International Airport, where a healthy mix of tourist and business customers made it the most lucrative route on the planet"
So 12 flights a day would be $1Bn? A major route could have that kind of frequency. A billions dollars doesn't seem absurd.
The airline business is notoriously unprofitable, so yeah, the amount of revenue required to make a billion dollars profit would be something absurd, possibly more than the entire industry on many years