Questions have been raised after a watchdog highlighted concerns over the speed of response by police helicopters.
It took on average 30 minutes and 58 seconds for helicopters to arrive on scene but there were significant differences between police force areas, a report by Her Majesty's Inspectorate of Constabulary and Fire and Rescue Services (HMICFRS) found.
In Nottinghamshire, it took the National Police Air Service (NPAS) 40 minutes and nine seconds to dispatch an aircraft to the county - one of the slowest response times nationwide.
Chief Constable Alec Wood, chairman of the National Police Chiefs Council's operations co-ordination committee, said: "We requested this study by HMICFRS and will use its findings to shape a new strategy for police air support that will resolve the issues with our current provision and take advantage of new technology.
"We have already started to progress some of the recommendations and have recently surveyed all forces to help inform our plans.
"NPAS has been the first specialist capability that has been nationally managed, a complex task involving 43 forces with varying requirements."
Here is a breakdown of the average helicopter response times for police force areas across England and Wales, from slowest to fastest:
:: Cumbria - 66 minutes, 33 seconds
:: Dyfed-Powys - 57 minutes, 42 seconds
:: Lincolnshire - 51 minutes, nine seconds
:: West Mercia - 41 minutes, 39 seconds
:: Derbyshire - 41 minutes, 14 seconds
:: Norfolk - 40 minutes, 20 seconds
:: Nottinghamshire - 40 minutes, nine seconds
:: Staffordshire - 38 minutes, 36 seconds
:: Gloucestershire - 37 minutes, 16 seconds
:: North Wales - 37 minutes
:: Cambridgeshire - 36 minutes, 42 seconds
:: Kent - 35 minutes, nine seconds
:: Devon and Cornwall - 34 minutes, 16 seconds
:: Wiltshire - 34 minutes, one second
:: Bedfordshire - 34 minutes
:: Warwickshire - 32 minutes, 21 seconds
:: Hertfordshire - 32 minutes, 14 seconds
:: Gwent - 31 minutes, 24 seconds
:: North Yorkshire - 30 minutes, 59 seconds
:: Hampshire - 30 minutes, 43 seconds
:: Suffolk - 30 minutes, 29 seconds
:: Sussex - 30 minutes, 10 seconds
:: Cheshire - 29 minutes, 29 seconds
:: South Yorkshire - 29 minutes, four seconds
:: South Wales - 28 minutes, 36 seconds
:: Lancashire - 28 minutes, six seconds
:: Northamptonshire - 26 minutes, 31 seconds
:: Avon and Somerset - 26 minutes, one second
:: Merseyside - 25 minutes, 26 seconds
:: Leicestershire - 25 minutes, 18 seconds
:: Essex - 24 minutes, 58 seconds
:: Thames Valley - 24 minutes, 16 seconds
:: British Transport Police - 23 minutes, 48 seconds
:: Surrey - 23 minutes, 44 seconds
:: Dorset - 22 minutes, 55 seconds
:: Durham - 19 minutes, 13 seconds
:: West Midlands - 18 minutes, 38 seconds
:: Cleveland - 18 minutes, 12 seconds
:: West Yorkshire - 18 minutes, three seconds
:: Northumbria - 17 minutes, 36 seconds
:: Greater Manchester - 16 minutes, 32 seconds
:: Metropolitan Police - 10 minutes, 37 seconds