H-34 Choctaw/Systems

1 Helicopter

1.1 General

The Shergood H-34/S-58 is a piston engine helicopter designed for transportation of cargo and for search-and-rescue operations in day, night, visual and instrument conditions. The helicopter is powered by a 1,525 hp Wright R-1820-84 Cyclone rotary engine mounted in the nose of the aircraft. A drive shaft from the engine feeds diagonally up to the main transmission mounted under the main rotors. Fuel is carried by three cells on the belly of the aircraft. An entrance door is located on the forward right side of the main cabin with a hydraulic winch mounted over the door.

1.2 Gross Weight

The maximum gross weight is 13,300 pounds.

1.3 Pilot-Side Instrument Panel

Figure 1: Pilot-side instrument panel

1. DME	2. RMI	3. Attitude Indicator	4. Tail-Number plate
5. Airspeed Indicator	6. Altimeter	7. Radio Altimeter	8. Checklist
9. Fuel Indicator Selector	10. Fuel Indicator Test	11. Fuel Indicator	12. Turn/Slip Indicator
13. RPM Indicator	14. Manifold Pressure	15. HOBBS Time	16. #2 VOR
17. VSI	18. #1 VOR	19. 8-Day Clock	20. Tail Wheel Lock

1.4 Copilot-Side Instrument Panel

Figure 2: Copilot-side instrument panel

1. Tail-Number plate	2. Airspeed Indicator	3. Attitude Indicator	4. RMI
5. Airspeed Indicator	6. Turn/Slip Indicator	7. Altimeter	8. 8-Day Clock
9.Manifold Pressure	10. VSI	11. Radio Altimeter

1.5 Center Instrument Panel

Figure 3: Center Instrument Panel

1. Pri. Hyd. Press	2. Aux. Hyd. Press	3. Main Trans. Oil Press	4. Main Trans. Oil PrTr,ss
5. Chip Indicator	6. Main Switch Panel	7. Checklist	8. DC Volts/Amps
9. Carburetor Temp.	10. Cylinder Temp.	11. Oil Temp/Press, Fuel Press	12. UFH Radio
13. Transponder	14. Parking Brake

1.6 Overhead Panel

Figure 4: Overhead Panel

The overhead panel includes various miscellaneous switches including most of the lighting controls, and controls for the hoist and heating systems.

2 Landing Gear System

The S-58 has a fixed landing gear system with two main wheels in the front and a tail wheel in the rear.

2.1 Parking Brake

A parking break is located in front of the co-pilot seat under the center console (Item #14 in Figure 3). Activating the parking brake will increase resistance to ground movement. Click the handle to toggle its position, or use the chat command:

s brake

to toggle it.

2.2 Tailwheel Lock

A tailwheel lock is located on the pilot side below the pilot console. Click the handle to toggle its position, or use the chat command:

s taillock

to toggle it. The tailwheel lock should be used during rotor engagement to prevent the helicopter from turning on the ground during the high-torque stages of engagement.

3 Engines and Related Systems

Figure 5: Engine: 1) Supercharger, 2) Carburetor, 3) Aux. Hyd. Pump, 4) Dual Magnetos, 5) Wiring Harness, 6) Starter

Figure 6: Piston

The S-58 is powered by a 1,525 hp Wright R-1820-84 Cyclone, a 9-cylinder rotary engine mounted in the nose of the aircraft (see Figure 5). A drive shaft oriented at 45 degrees passes through he main cabin up to the main transmission. The cylinders (see Figure 6) are arranged around the drive shaft of the engines at 40 degree intervals. Each cylinder two spark plugs, each powered by a different engine driven magneto.

3.1 Throttle

right

Figure 7: Throttle

The throttle is controlled by a twist grip on the end of the collective (see Figure 7).