Rocky Mountain Helicopters Inc. has added three BK-117 helicopters to its fleet at a cost of $7.2 million, bringing to 120 the number of aircraft the company operates. The total includes 99 helicopters and 21 fixed-wing aircraft.

J. Russell Spray, vice president of the company's medical group, said the increase in the number of aircraft reflects an increase in the company's operations. "The growth of the medical group has been higher than projected and will require three additional aircraft to keep abreast of the demand," he said.One of the new helicopters will operate as a backup unit and the other two will be fitted with medical equipment for deployment to areas where Rocky Mountain has been contracted to provide support next summer.