Earlier quoted context omitted.
It's worse than having one sensor, the chance that one of two breaks is larger than that just a single one breaks. And by alternating you ensure that the broken sensor will be used.
Was talking to my flight instructor about twin engine planes. He was adamant that they were LESS safe than single engines because 1) you are twice as likely to have an engine failure and 2) the statistics indicate (non-intuitively) that an engine-out in a twin is more likely to lead to fatalities. He said the insurance companies used to think twins were safer but they have adjusted their rates after looking at actual…
The only reason I know is because the captain informed us about it and added that since it was technically an emergency landing we would be greeted by the fire department.
He then turned the plane around and landed as if nothing had happened.
The bloke across the corridor, an old pilot, complained about how there never happened anything remotely exiting on any of his flights ;-)
[0]: to be as accurate as possible I think what he said was they'd lost oil pressure on one engine and decided to shut it down voluntarily.