When something goes awry, either an engine failure, fire, or deviation from the planned flight route, the ground station alerts all relevant parties, who can then access the planes data and voice.

All planes are required to have microphones and small video cameras embedded throughout the aircraft, not only the cockpit, but in the passenger area, bathrooms, even the cargo area, and the outside of the plane, so the whole condition of the aircraft can be inspected - if a fin isn't responding properly they can see it on a monitor.

Cameras and microphones in the cockpit can NEVER be turned off. They are not optional - they are ALWAYS ON and accessible. The cameras and microphones can be hidden in several places, behind instruments in the panels, in the air conditioning, etc...

Larger aircraft (or perhaps ALL aircraft) are equipped with a re-designed cockpit which looks and operates as cockpits do today, but are retro-fitted in such a way that every knob, dial, lever, etc... is not "hard-wired" directly to the planes controls but rather is routed to a "central control unit" elsewhere in the aircraft. Under normal conditions, the CCU simply relays the cockpit controls to the various aircraft systems.

In situations where the crew becomes unable to control the aircraft, either because of a fire, a heart attack, or a hijacking, the central ground station is alerted where pilots trained in emergency manouvers are on standby - and have access to one of many "cockpit simulators".

These simulators can be set to take over complete control of the aircraft. In order to work effectively, there must be a extremely reliable wireless network made up of satellite and ground transponders that are capable of relaying vast amounts of data in real-time between the central ground station and the aircraft. High-definition 3-D video cameras at the front of the aircraft capture a panoramic, three-dimensional view that is as good as or better than the view from the cockpit.

The pilot at the ground station must see exactly what the pilot of the aircraft would see. All the knobs, dials guages, and levers on the ground station cocpit must be motorized to match exactly what is in the aircraft. Signals sent from the ground station cocpit controls are relayed directly to the CCU on the aircraft, overriding the aircraft's cockpit. The pilot at gound station can then operate as though they were in the aircraft itself and guide it to safety.

A security team at ground control can monitor the conditions in the remainder of the aircraft and take control of situations they may put peoples lives in danger. In a hijacking situation, since they can no longer control the aircraft they can threaten the lives of the passengers with weapons or bombs. The simplest solution may be for ground control to trigger a switch which releases a sedative gas into the aircraft that simply puts everyone to sleep, or safely immobilizes them long enough to get the plane returned to a safe place.

There would inevitably be a 2 or 3 second time lag between the ground control and the aircraft, and the pilot on thr ground would have to be specially trained to accomodate this time lag. Improved wireltss networking technology and digital signal processing might help to reduce this delay, and if there were enough "central controls" around the world we could overcome the sluggish speed of light as well.