In 1973 Frontier had sold off it's fleet of 727-100s and 200s in favor of 737-200s. The balance of the fleet was comprised of Convair 580s. The airline hired the first female pilot for a major airline in the year. Profits were strong as Frontier reached it's ultimate financial health. Note the presence of numerous subsidized routes to small towns such as Ponca City, Oklahoma and Hays, Kansas.