Boeing Model 401 helicopter

[hesham]

Hi,

http://www.aviastar.org/helicopters_eng/boeing_model401.php

 

[hesham]

From, ROTARY WING AIRCRAFT HANDBOOKS AND HISTORY VOLUME 14,

they spoke about Stearman helicopter Project under design in 1943,and I know this company became a
part of Boeing before that time,but I don't know if they meant this concept or what ?.

 

[hesham]

From Boeing (Planemakers 1).