Pilotless pax aircraft?.....It will never happen....Why?
1. Pilotless aircraft crash. Check the stats for UAV systems on the web. They are complex flying systems which also include the ground control station and the associated RF links.....What happens if the ground control station is hijacked, or a spurious uplink message is sent?.... Aside from that, there are many system type failures that could occur.....
2. Pilots onboard on aircraft have a self preservation interest. Pax like that feature. It gives them confidence in flying safety.
3. Controlling/monitoring a pilotless aircraft will require an uplink/downlink system. The RF spectrum bandwidth is gradually being eaten away by other commercial interests, and this is a real limitation to unmanned systems at this time. It won't get better.
4. The development costs will be high in order to provide the level of reliability required for pax operations. Think about certification of such systems....It goes a lot further than what is covered in FAR Part 25.
Regards
Woxman