a byron fan assembly puts out 12 to 14 pounds of thrust pending on the outlet of the thrust tube you can buy them on ebay or here on rc univerise i am all for the byron fan because its a pusher fan so the motor is in front of the fan and does not interfere with the air flow in the thrust tube you being a areospace engineer understand the propertys of air flow and restrictions of air from stationary obstacles interfering in the airstream just my opinion good luck with your project keep us posted on your design of aircraft donniercjet