Separate luggage from the passengers!
There should be Cargo Planes which will handle luggage for multiple Airlines by destination which would arrive at approx same time with the Passenger planes. People already have all they need on the plane: food, drinks, seat mounted computer tablets, internet and movies. They don't need their luggage while airborne! Pros: 99.9% safety guarantee! Cons: will require scheduling changes. The Pros overweight the Cons!