Every large commercial aircraft has what is known as a “black box”. In fact there are two of these devices, a flight data recorder and a cockpit voice recorder. The big problem with these devices is that they are fixed inside an aircraft and when that aircraft crashes, the black boxes crash with it.If the aircraft crashes on land, the black boxes may be destroyed by the impact or burned beyond recovery by fire. If the aircraft crashes into the ocean, it may do so in a place where recovery of the black boxes is impossible, such as in the Mariana Trench, 11 kilometres below the surface. My idea is this. Instead of having a separate flight data recorder and a cockpit voice recorder, these two devices should be combined into one compact floatable unit. Then two of them, operating autonomously in parallel, should be fitted to the aircraft with pyrotechnics that would automatically jettison them from the aircraft in the event of a crash, whether on land or sea. If an aircraft crashes on land, then the black boxes would be jettisoned away from the aircraft and clear of any fire that could destroy them. If the aircraft crashed into the ocean, the black boxes would be jettisoned on impact or by way of pressure sensors that would deploy them from around 50 feet underwater so that they would float to the surface. Each black box could be equipped with the usual emergency beacon, but also with a GPS receiver that would broadcast the exact GPS position with the beacon. That way, even if the aircraft sank in 1000 metres of water, those beacons would be in the immediate vicinity on the ocean surface, broadcasting the beacon and the exact GPS location. Apart from the two deployable black boxes, another beacon could be fitted to the aircraft to broadcast a signal with GPS data so that direction finding equipment could pinpoint the aircraft on the ocean floor. This beacon could broadcast that signal with GPS data in normal flight, so that the aircraft’s position can always be pinpointed. For security and to protect against a pilot-initiated deactivation of the black boxes, they would be fully automatically deployed and pilots would not be able to prevent this in any way. The black boxes could be located at the rear of the aircraft, for instance in the base of the rudder. The beacon could be located in an area inaccessible to pilots or crew to prevent deliberate deactivation. Both black boxes and the beacon would have continuously recharging batteries, so that even if power from the aircraft was somehow cut to them, they would still operate for at least one month, so that they would keep transmitting a signal with GPS location for that length of time. This would solve the problem of finding aircraft, such as Malaysian Airlines MH-370 that simply vanished. If an aircraft can be tracked constantly by signals and data from beacons that are fully autonomous, inaccessible and completely beyond the control of pilots and crew, then literally every aircraft fitted with such devices could be found, whether they were hijacked, deliberately diverted or crashed either on land or in the ocean. Cost would not be an issue. Large aircraft already have two black boxes, so the only difference in cost would be to fit them with new combined data and cockpit voice recorders and pyrotechnic ejectors and flotation devices. The beacon would be nothing more than a small transmitter with a backup battery. The cost of all this would be negligible when factored into the total cost of an aircraft. However, the benefits would greatly outweigh the relatively small cost of fitting or retrofitting such devices. Airlines would know that they would always be able to locate crashed aircraft. The astronomical cost of scouring oceans for months, such as in the Malaysian Airlines MH-370 incident, would be eliminated.