I have been saying this since MH370 and AirAsia....why not fit GPS spot locators in the tail of aircraft? The type that hikers use are waterproof, report every minute (could be set to 10 seconds) and could be attached to an uninterruptable power supply in the tail. Even if ship power goes out, these units have batteries that can power them for days. Every aircraft in the world (private aircraft notwithstanding) can have position known to GPS precision at all moments up to any impact (and if on land, could keep running for days.) If submerged to a seabed you would lose the location due to depth and signal, but you would know where an aircraft hit the water....And cost? This can be done for LESS than 100 dollar per plane, per year.