What are the differences between A220 and A319neo, and how do those make the A220 a more preferrable option for airlines than A319neo?
The operating cost is significantly lower for A220 than A319NEO because it's a clean-sheet design and 300 is the non-stretched variant. So initially, aircraft designer optimized everything around A220-300.
Now, certain airlines like Spirit still decide to pick A319NEO due to the cost savings from operating a single fleet vs dual fleet. There are a lot of additional redundancy and costs associated with adding fleet that I'd rather not get into.
But that's the trade off that airlines makes.
Just putting things in perspective. A220-300 for Jetblue has the same operating cost per trip as E90 despite have 40% more seats.
Its operating cost per seat is at same level at A320NEO (possibly even lower) despite having maybe 20-25 fewer seats. So normally, as aircraft gets larger, you'd expect cost per seat to go down, since you have to fill more seats at lower fares.
so economically, A220 series is currently the best aircraft in the market, but its production numbers are still low and Airbus doesn't want to cannibalize A320NEO sales.
You don't really have that problem with C919. So i've always suggested for COMAC to do C909 to replace ARJ-21. But you'd need the clean sheet to start at maybe 120 seat single class and extend to 170 seat