STUDIES OF HUMAN FACTOR IN PANEL DESIGN 



157 



the control was not beyond the Hmits of 

 reach if the pilot stretched from the resting 

 position, but rather were out of reach be- 

 cause the pilot had to stretch in the opposite 



it should be obvious that we can now deter- 

 mine the hmits of reach of any population 

 in any kind of equipment panel without re- 

 sorting to guesswork. With the techniques 



30r 



52 



tr. o 

 o z 

 u. u 

 ^ cc 



o 



10 



SEAT 



REFERENCE 



POINT 



Fig. 4. Maximum distances which can be reached with the right hand by 97% of a selected Navy popu- 

 lation at vertical intervals from 46" above to 2" below seat level. (After King et al., 21) 



CENTER TO CENTER DISTANCE 



A, Aj : 9 I' 



B, B, = 12 



'2 



C, =13 7 



DIAMETERS 



CIRCLE A -34 6'(P 20'' V. 0, 

 CIRCLE B -4 J b"(S> 20"V. 

 ORCLE C-62 0«> I O'V 



CIRCLE A - VERY CONSERVATIVE, INCLUDES 95^ OF all PERSONNEL 

 CIRCLE B - AVERAGE MAN, SO/: ■ 



CIRCLE C -LARGEST MAN. ■■ S7. ■■ 



Fig. 5. The limits of maximum working areas on a vertical surface. (After Lipschultz and Sand- 

 burg, 24) 



direction to operate another control at the 

 same time. 



Taken together, these studies offer the 

 kind of specific data that are necessary for 

 efficient panel design. In the first place, 



available, it is possible to specify precisely 

 what areas of a panel a particular percentage 

 of the population can reach without stretch- 

 ing or straining. There should be no excuse 

 for unforeseen diflSculties on this score in 



