It may be 5 not 6 - the Independent thinks Lincs & Notts are two aircraft. But then they don't mention Yorkshire Air Ambulance specifically.. on
this page they say
Kevin Hodgson, director of operations at Great North Air Ambulance, said they had sent two air ambulances, which were joined by two from North West Air Ambulance and another two from Lincolnshire and Nottinghamshire Air Ambulance.
Two from North West in photo below from the
story on the Mail website