Within the UK EMS is performed principally by Air Ambulance Units.
All taskings must come via a regional Ambulance Service control centre to satisfy the legalities of claiming exemptions under the Air Navigation Order, Rules of the Air and JAR-OPS where operations operate under it.
An emergency helicopter flight which proceeds directly to the scene of the incident/accident is known as a primary mission.
For these taskings, more correctly known as HEMS (Helicopter Emergency Medical Service) taskings, exemptions from the ANO to permit low flying for recon, approach and take off over congested areas, flight in closer proximity to 3rd parties & reduced flight visibility.
Relaxations may also be applied regarding aircraft performance providing deviation from optimum performance is for the shortest possible period.
These dispensations may only be claimed where life is percieved as being lost and "where immediate and rapid transportation" is required.
If immediate and rapid transportation is not neccessary and the injury/illness is not felt to be life threatening an exemption may not be claimed and therefore the helicopter may only alight and depart from areas which do not require the pilot to claim any dispensations, or from pre-surveyed landing sites within the Helicopter and Hospital Helicopter Landing Site guides.
Where this is the case the tasking is more correctly referred to as an Air Ambulance Tasking.
These flights are subject to normal public transport rules and performance criteria.
Because of the definition of a HEMS task as being one in which the helicopter proceeds directly to the scene of an incident, if a casualty has been moved from the accident scene to another location deemed to be more suitable for helicopter alighting, any attempt to land there will not permit the pilot to use dispensations and may be impossible to perform legally.
Similarly, when landing at hospital sites public transport performance must be maintained unless the patients condition is deemed to be life threatening.
Occasionally the only way to do so it to land at larger sites permitting a flight profile which is safer in the event of a forced landing.
As someone remarked above, it is not good practice to bring more casualties to an incident, however there is a disturbing trend amongst Ambulance Services to respond HEMS helicopters to trivial complaints and then place the crews under moral and ethical pressure whether to breach the rules established for their safety and that of the patient and others.
Frequently, this will occur because if not lifted the patient faces a long and distressing wait in a field for a land ambulance.
HEMS crews work hard to keep themselves and others safe but there is inherent risk in flying, which those who inappropriately task these resources do not worry about because they just want to clear up jobs and they are not risking their life and license when it all goes wrong trying to lift a broken ankle of a football pitch....................
