directional stability. ......................... 284 
divergence ................................ 245, 342 
downspring, ................................. 270 
downwash ................................... 66 
drag 
coefficient. ........ ................. 29 
equation ................................... 29 
induced ................................... 66 
parasite. .. .. ..... ... ............. 87 
total ...................................... 92 
dynamic pressure. .... ... .... ............ : 9 
dynamic stability., ... .... .... ... ....... 245 
efficiency factor. ..... ... ...... .. ....... 89 
414