TM-5-3740-210-12
A manually controlled flapper-type gate valve is placed in the output line of the pump at the boom tee. On the
right side of the aircraft, the extended tank outlet is utilized for bottom loading of the tank from a pump powered supply
source or for use as a quick draining of the tank. All fluid tubing and hoses have connections several inches outboard
from the aircraft to eliminate leakage into aircraft from externally extended spray boom and spray pump fluid lines.
The windmill is manually adjustable on the ground and utilizes six (6) molded nylon fan blades designed for
maximum power development at low aircraft speeds. "lade pitch settings are collectively positioned, from a single
adjusting screw, to any selected angle from 10 to 90 degrees to derive a given rotational speed or may be feathered
when desired. Overspeed rotation at high helicopter flight speeds is automatically limited by aerodynamic design.
The spray boom extends 31 feet 5.56 inches from tip-to-tip and contains threaded provisions for nozzles every
four inches, starting two feet outboard from the body of the helicopter. The boom is constructed of standard aluminum
extrusions. Its cross-section is circular with a built-in boss provided along its entire length into which any number of
threaded holes may be tapped for additional nozzle installation. The spray boom is supported vertically by a diagonal
tube strut and a supporting cable attached to the top of the tank. Fore and aft motions of the boom are restricted by
horizontally adjustable cables attached to the lower section of the tank support structure.
The spray system is manually controlled in flight by a lever mounted on a control panel attached to the tank
structure swinging down between the pilot and co-pilot seats. The system is operated by the co-pilot or other crew
member by actuation of the lever which opens and closes the control valve.
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