New police air service takes off
A new National Police Air Service is replacing localised police helicopter operations in England and Wales.
The service of 25 helicopters at 23 bases, some not operating round the clock, is expected to save £15m a year as seven other bases are closed.
The Association of Chief Police Officers hopes for 20-minute response times for 98% of the population.
But some police crew members fear the service will be stretched and slower responses could endanger lives.
Helicopters are used by police to track criminals, monitor major incidents and locate missing people.
It is estimated that the national service will cut the cost of running air support from about £63m to £48m a year.
Policing Minister Damian Green told the BBC the key was to have the helicopters in "the right place" and "deployed faster".
"Crime or the need to search doesn't stop at county boundaries. It is actually the deployment and the speed of deployment that makes a difference," he said.
Mr Green rejected the suggestion that the change would result in response times increasing or lives being put at risk or lost.
"There will be more helicopters available more of the time because you've got the resilience of having a national structure," said Mr Green.
"They will be deployed faster and there will be more aircraft available to do it, so people will get a better service now.
"This is a police-driven decision. They wanted a national air service because they knew they could provide a better service with this type of structure than the previous fragmented structure we had."
West Yorkshire Police have opened a centralised aircraft despatch centre, based in the Bradford area, for the new service.
Hampshire Police Chief Constable Alex Marshall said of the old system: "Artificial boundaries have meant that helicopters are restricted to operating within their own force area or consortia.
"A truly national, borderless service will ensure effective coverage of urban and rural areas."
Lives 'at risk'
Brian Greenslade, of the Association of Police Authorities, said: "From catching criminals to ensuring the safety of crowds, helicopters and other means of air support are essential tools in the fight against crime, but they are costly and in some areas used infrequently.
"This programme should ensure that forces retain the right capability to call on air support to protect the public whilst sharing its considerable costs."
But one police crew member, speaking anonymously to BBC News, said lives would be "put at risk or possibly lost" because it would take too long to get to incidents.
He said the new service, which is being phased in from 1 October and will include three reserve helicopters, was focused on cost rather than capability.
However, that claim has been denied by Supt Richard Watson, from the National Police Air Service (NPAS), who said while there were fewer aircraft, they were flying the same number of hours.
"We have made some changes to the bases so they're more strategic bases covering a greater area. Under NPAS the principle is the nearest aircraft attends. It's borderless tasking," he said.