1200 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1957 



f.5 

 1.4 

 1.3 

 1.2 



1.1 

 1.0 



^0.9 

 5 0.8 



0.7 

 0.6 

 0.5 



0.4 

 0.3 

 0.2 

 0.1 



0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 



cosh a 

 Fig. 37 — Variation of — j— with a. 



values we assume for the parameters which enter the calculation are thei 

 following: 



e = 0.02, 



7 = 6 knots, (a ;^ 12°), 



h = 6,000 ft, 



M = 1.2 X 10' lbs, 



A = 3.1 X 10"'. 



To solve (99), we connect on Fig. 36 the points e = 0.02 and h = 

 wh/EA = 0.0031 with a straight edge and note the intersection with 

 the intermediate y-i = y^ixs) curve for a = 12° (point A). We then locate 

 the point on the y-i versus o- curve having the same ordinate (point B). 





