Some Mercy Flight patients experiencing severe blood loss will now have a better chance at survival.

The helicopter ambulance service will start carrying type O blood on all its ambulatory flights.

The change comes after a bill was passed last year allowing air ambulances to transfuse blood while in transit. New York was the last state to allow it.

It's estimated that one-third or more of patients in air ambulances need blood transfusions but they had to wait until getting to a hospital to receive it.

"It is our belief that this initiative will save lives and serve as a template for the expansion of pre-hospital blood transfusion across New York state, for the benefit of the most critically ill and injured patients, when minutes matter," said Dr. Michael O'Brien, Mercy Flight associate system medical director.

The blood will come from the Western New York donation center, ConnectLife.