Remember, we are in the 21st century, one button push by Air traffic control room as soon as the plane is untraceable will trigger the Naval and Air force military rescue operations and within 1 hour's time the people who have dived with the parachutes will be rescued.
I used to work in Air Force combat search and rescue. We have great technology and capabilities, but sometimes it is not so simple and not always possible to rescue someone within 1 hour time. It would be much easier to find aircraft crash survivors if they are all together with the aircraft after a survivable crash. When aircrew egress from an aircraft with parachutes, each one must carry personal survival equipment which is personally prepared and tailored for every separate mission and pilot by a specialist in survival and rescue, and they must carry a survival radio in order for us to locate them.