1. Boarding been so slow the APU burn has reduced the fuel in tanks to under that required on the flight plan by 100 kg - Do you go with the loaded fuel anyway, using the various bits of wriggle room available in the regulations or will the computer simply say "no" and demand the bowser is brought back for a top up?
If the fuel is within a tolerance limit the flight dispatcher in the flight control center can override the warning and dispatch the flight. If it is below tolerance the plane says 'NO'. It's a machine after all - it isn't worried about getting its bonus or pressing on to make it home in time to tuck the kids in bed etc.
Besides - no one will be running an APU on the stand 20 years from now.
2. ATC offering an alternative T/O runway or intersection to one that's been flight planned and "programed", ( What do you reckon HAL, stick with the plan or reprogram? )
Issue a command to the aircraft over an interface. Isn't something similar being implemented already (i.e. ATC will send electronic messages to flight crews instead of communicating via voice)?
3. The medical emergency on a winter's night over the north Atlantic at 30 degrees west - do you divert to x rather than y? Distance to x is marginally less than distance to y, but x has a single icy runway and wind that's just on limits, y takes 5 more minutes to get to but it has excellent medical facilities just off the airport, it's runways are dry and the wind is calm ( Are you listening HAL? ..HAL?... "I'm sorry David...)?
Supervisor in flight control center is alerted, assesses situation and makes the call.
Divide the cost of the pilot over the amount of passngers they have flown per year and you roughly get the price per ticket of having them up front. It would work out at a low figure (getting lower) and the amount of people put off flying without them would probably cost more.
Quick look at the BA income statement show salaries and wages contribute nearly as much to cost as fuel does. How many tens of millions did Lufthansa lose on the recent strikes? These are not small figures we are talking about.