T course. M is now the resultant of the Thrust and the Momentum, and you will note that this results in a

decrease in the angle our old friend the neutral lift line makes with M, i.e.,
a decrease in the angle of incidence and therefore a decrease in lift. We will suppose that this decrease

is 2 degrees. Such
decrease applies to both main surface and stabilizer, since both
are fixed rigidly to the aeroplane. The main surface, which had 12 degrees angle, has now only 10 degrees, i.e., a loss of ONE-SIXTH. The stabilizer,

which had 4 degrees angle, has now only 2 degrees, i.e., a loss of ONE-HALF. The latter has therefore lost
a greater PROPORTION of its angle of incidenc e, and consequently its lift, than has the main surface. It must then fall relative to the main surface. The