When someone is seriously injured, EMS personnel need to decide whether transportation by ambulance or helicopter will get the patient to the trauma center sooner. There are several considerations:

• Ground travel time to the nearest trauma center (e.g., distance, traffic congestion)
• The helicopter's estimated time of arrival (ETA), transfer time, and flight time to the trauma center
• Whether multiple patients are involved

Factors which should be taken into account are:

• Ground transport should be used for an un-entrapped patient who is within 30 minutes ground travel time from a trauma center.
• Entrapped patients are an exception to the 30-minute rule, if the helicopter can reach the scene while the patient is being rescued or extricated.
• Consider requesting a helicopter for incidents involving more than three critical patients.