The Federal Aviation Administration certified the Boeing 737 Max 7 after nearly a decade of delays. The Max 7 is the smallest model of the family of aircraft, which has been a favorite among airlines, CNBC reported. While airlines can begin scheduling flights with the aircraft, it may take months before they work them into flight schedules. Southwest Airlines called the certification an "important step" toward modernizing its 737 fleet with improved interiors and more fuel-efficiency. Boeing is still awaiting certification of its 737 Max 10, the largest of the line, as well as the manufacturer's largest aircraft, the 777X.