As of March, more than 11,700 Boeing 737 family aircraft had been sold. Boeing also holds a healthy order book, with approximately 5,000 aircraft across different variants. How did it all start? While the latest members of the 737 family aircraft, such as the 737 MAX 9 and 737 MAX 10, are large and can accommodate over 200 passengers, the original Boeing 737-100 was significantly smaller than these.