As this thread swings from mandatory twin pilot IFR to landing on scene at night it is important to remember that EMS is totally different in the UK from the US.
In the US many helicopter systems are bolted on to hospitals because they are needed to provide adequate population numbers for specialist services. Many systems operate secondary transfers, often involving patients with low levels of pathology, again so regional centres can exist outside big cities. Neonates need to be transferred far more frequently over longer distances and trauma is far more common and severe.
In the UK we dont have community hospitals and since 1997 more and more hospitals have provided all but the most specialist services so that the trauma concept of 1990 has been abandoned and the much lower number of trama victims are taken to the local hospital. Neonatal transfers are less common, involve shorter distances, and paediatricians normally manage most transfers with specialist ground vehicles. Inter ITU transfers by helicopter have been shown to save lives, but the specialised equipment is quite different from a HEMS helicopter and to put it bluntly the NHS wont pay.
So in the UK there is little evidence of lives saved; the London hospital's HEMS was very carefully audited but the only 'life saving' was severe head injuries and the cost was many times that of even heart transplantation. As a result we are likely to continue to see EMS helicopters used by ambulance services as opposed to hospitals, for rural areas and to help ambulance managers meet time targets. That is not to say they do not have major benefits including pain reduction and freeing ground units but life saving doesnt stack up financially or logistically.
As such running daylight only systems seems to be sensible, together with a proper chinese wall such that despatchers and pilots do not know the medical indications of the mission. The idea of landing on scene at night terrifies me and the potential benefits are questionable. However, having flown in the back of these ships both sides of the atlantic I despair at the holier than thou attitude towards the US with its totally different needs and driving forces. I am sure most US operators wouldnt turn away full IFR ships and would like the opportunities to reject more flights, but hospital operators asnd indeed patient needs demand otherwise - for the present at least.