I'd just imagine coordinating with every airport and airport mechanic team to go through this process, have some integration work with the MCAS which has to be done very carefully and thoroughly. Everything is more expensive when you have a super high level of risk management and are working with large bureaucratic organizations like airlines and the FAA.
But yes it's certainly not impossible sounding. It's like a minor recall where the planes get fixed on site.
Hundreds of people are already dead because of this. It's the very minimum they can do to prevent more deaths. Whatever the cost is of adding another sensor will be less than the cost of another crash.
But yes it's certainly not impossible sounding. It's like a minor recall where the planes get fixed on site.