Originally Posted by
Blondie2005
However, I am absolutely flabbergasted that my phone and tablet can be tracked by GPS if they go astray, but according to an article on the BBC planes cannot, and black boxes cannot.
Your tablet can't be tracked if the wi-fi is turned off. Your phone can't be tracked if it's in 'airplane mode'. Neither can be tracked if they're 2,000m underwater.
Similarly, you can't track an aircraft by ADS if it's not sending ADS messages anywhere, due to transmitter failure or whatever. Had they continued sending ADS messages, we'd already know where they were to within a few tens of miles.