But carrying a spare engine all the time? that's a waste and someone has to pay for it.
Describing it as a spare engine gives the impression that it's surplus to requirements. I've been flying twins for 18 years and always considered them invincible, that is until I had an engine failure in one while carrying out a helipad departure. Outcome? Rejected back into the area I'd just departed without injury to aircraft occupants, members of the public nearby and no damage to the aircraft. Singles aren't an option for the sort of work your average Air Support Unit or Air Ambulance carry out. If you go through life thinking the worst is never going to happen, one day you'll be in for a nasty surprise.
I'm well aware that singles are cheaper to run than twins, but if you want to do any job properly you need the right tools. Under the current legislation operating a single in this country would severely restrict activities in built up areas and at night and would result in an inaffective aerial deterent to crime. If the government of this country are serious about reducing crime, they need to realise that the proper funding needs to be put in place to not only sustain the Air Support infrastructure we have at the moment, but also to allow for upgrades as new technology becomes available.