236 SYMPOSIUM ON AERONAUTICS. 



Case I. — Side-gust — sharp. v^=J(i — e-'^^). 



/„ = /(— I + .oi473^-'0, /.o = — .98527^ 



I^ = J( — .001028)^-^', -^.^o^ — .001028/, 



/'^=/(. 00514)^-^', /'^o= -00514/, 



/r = /(. 002706)^-", I r 0^=^.002706 J, 



Coi = • .000384/, Coo = .0005364/, 



Coo = .000809/, <^24 = .0002445/. 



The equations of motion are 

 iooo<^// = — .384^''2"6f _|_ .536^-«"2«_ i.028£r=* 



_[_^-.3268«(^_gQgj (.Q5 1.215? -f .2445 sin I.2I50- 



This is all negligibly small. For the same reason certain terms may 



be neglected in v and r. 



^^j--QQ^g.02i36t _|_ .oo2^-^"2« — I _[_ .01473^-=* 



^ g-.s2c&t^gg cos 1.215? — .2022 sin 1.215O1 

 ioor/J = — .oie'^^*^^' -{- .2yie-^^ — ^-•2-''^' (.257 cos 1.215? 



-f 1.009 sin 1. 215?). 



The effect of the sharp side-gust is to carry the machine side- 

 ways with it, but not very powerfully at first — much of the air blows 

 through the machine — the dominating term at first being 



v=^ — .2/c"-^2*^^^ sin 1.215?; 



after a few seconds the dominating term is v = — /, with the very 

 slowly growing divergent term effective only after a considerable 

 time. There is a slight yawing oscillation, but the extreme angle 

 of yaw is only about 0.01/ radians or J/2 degrees — the angle being 

 computed as 



looxP/J = f loor/J-dt = .4(1 - e-o^^^O -f .054(1 -C-") -.8316 



_|_ g-.32fi8<(_82i6 cos 1. 215? + .0122 sin 1.215?). 



The actual sidewise velocity is compounded of v and the amount 

 — 1 1 5-5"/' due to the yaw. Hence 



=X'(" 



IlS.5xly)dL 



