1930 Nothing Discourages a Boeing 40-B4 Ad 

Model 40B with NACA Cowling 

Model 40B with Passengers 

Boeing Model 40 with Special Passenger 

B-17s Modified as YB-40s at Douglas' Tulsa Plant with B-25s and A-24s 

Boeing Model 40B flying over mountain 

Boeing Model 40B in Flight Above Mountain 

Passengers and Pilot with the Boeing Model 40B Transport 

Model 40B-4 Mailplane Radio Ship Model 

Eddie Allen in the Cockpit of a Model 40B-4 

Model 40B-4 at Plant I Hangar 

Model 40B-4 Mailplane Manufacturing 

Model 40B at Boeing Hangar 

Model 40B mailplane