GoneWest why don't you take thrust out of the equation and consider a glider. It has a downward force due to its Mass and Gravity.
Newtons third law of motion states that every force has an equal and opposite force known as the reaction.
So now we have a glider with weight acting vertically down and the reaction acting vertically upwards. 2 Forces.
No, that's an abuse of Newton's third law. The 'equal and opposite reaction' phrasing of the law is concise, but leads to this sort of confusion. Newton's third law says that if Body A exerts a force on Body B, Body B exerts and equal and opposite force on Body A.
In the case you cite, the 'reaction' is the gravitational force that the glider applies to the earth, equal to the weight of the glider and applied vertically upward -- it has nothing whatsoever to do with the aerodynamic forces.