A new helipad on the grounds of the Mater Hospital in Dublin will be vital to the transfer of critically ill patients around the country.
A simulation involving the new helipad has taken place at the hospital, the first time it has been used.
The Army Air Corp helicopter landed at the Mater Hospital just before midday.
The demonstration involved the transfer of a simulated patient by helicopter to the hospital grounds, where she was seen by doctors within minutes.
The helipad is situated just 10 meters from the emergency department.
Dr Gerard O'Connor, Emergency Consultant at the hospital, has described how important it is for patients.
"It means that when the helicopter - when the aircraft - lands, that patient is greeted immediately by our medical and nursing team," said Dr O'Connor.
"They receive critical care in our emergency department and in our trauma unit immediately.
"So that care can commence pretty much when the aircraft touches down."
The Mater was granted planning permission for the helipad three years ago, and today's demonstration has been described as a big step in making it fully operational.