Yearbook^ of Agriculture 1949 



Spray Apparatus for N3N and Stearman Airplane 



1 Tank 70 to 80 gallons capacity, sloping bottom to provide positive drainage. 



2 1V4- by 1-inch centrifugal pump will handle solutions, emulsions, or suspensions. 



3 Relief valve, water type, adjustable, set for 25 psi; must have adequate capacity to 



maintain constant spray output at varying air speed. 

 4 Shut-off or control valve, quick acting cam type. 

 5 Nozzle boom, not less than 1 inch o. d. tubing, mounted beneath lower wing; fittings 



provided for 60 nozzles. 



(N3N and Stearman PT-17), which 

 can carry about 80 gallons of spray 

 and operate at 75 to 90 miles an hour. 

 They are not ideal for the purpose, 

 but they perform reasonably well, and, 

 being war-surplus items, their initial 

 cost is much less than that of many 

 nonmilitary models. 



Several other types of planes also 

 have been employed the light, high- 

 wing monoplanes that fly at 60 miles 

 an hour and carry only 25 gallons of 



spray, up to multiengine transports 

 that fly at 150 miles an hour and carry 

 1,000 gallons of spray. 



Helicopters, tested in experimental 

 work, may prove useful in specialized 

 operations because of their ability to 

 fly low and slowly and to maneuver in 

 small areas. 



SPRAYING APPARATUS because ae- 

 rial spraying is such a new and rapidly 

 expanding field has not been stand- 



