Pilot's Operating Handbook for Cessna 188 AGwagon

The following services are offered by most Cessna Dealers: FACTORY TRAINED PERSONNEL to provide you with courteous, expert service. FACTORY APPROVED SERVICE EQUIPMENT to provide you with the most efficient and accurate workmanship possible. A STOCK OF GENUINE CESSNA SERVICE PARTS on hand when you need them. THE LATEST AUTHORITATIVE INFORMATION FOR SERVICING CESSNA AIRPLANES, since Cessna Dealers have all of the Service Manuals and Parts Catalogs, kept current by Service Letters and Service News Letters, published by the Cessna Aircraft Company. We urge all Cessna Owner's to use the Cessna Dealer Organization to the fullest. A current Cessna Dealer Directory accompanies your new airplane. The Directory is revised frequently, and a current copy can be obtained from your Cessna Dealer. INTRODUCTION The Cessna Agwagon "A" is designed specifically as a safe, efficient, easy-to-fly aerial application airplane. The flying characteristics have been carefully developed so that the airplane can be maneuvered near the ground for long periods with maximum safety and minimum effort. In addition, the rugged structure and equipment are simple and easy to main- tain, further enhancing the reliability and efficiency of the airplane. In line with this philosophy it is important that the pilot obtain a thorough knowledge of the airplane and its equipment, as well as an under- standing of operational techniques. Toward this end the Owner's Manual emphasizes the basic design principles of various systems in the airplane, while minimizing operational information that is conventional and well known to agricultural pilots. The Agwagon "A" is offered with a standard 230 HP engine and stan- dard fixed-pitch propeller or optional constant-speed propeller, or with an optional 300 HP engine and associated constant-speed propeller. For convenience throughout the manual, these configurations will be referred to as (230 HP Engine, FPP), (230 HP Engine, CSP), and (300 HP Engine). Recognizing that a great variety of dispersal equipment will be in- stalled (and possibly modified) according to the operator's desires, most of the performance data in Section V has been presented for a "clean" airplane without dispersal equipment installed. This data is provided for each engine and propeller option. Additional data is included to show dif- ferential factors which must be considered for some typical dispersal equipment installations. Since these differential factors will vary with different types of equipment installations, each operator should use the data as a guide and make allowances according to the type of equipment installed on his airplane. i ii PRINCIPAL DIMENSIONS 10'-10° 7'-7" MAX * TABLE OF CONTENTS SECTION I - OPERATING CHECK LIST. Page= 1-1 SECTION II - DESCRIPTION AND -12° 25'-3' ** OPERATING DETAILS 2-1 SECTION III - OOPERATING LIMITATIONS.... 3-1 -10'-10". * Maximum height with optional flashing beacon installed. **Length with constant-speed propeller (no spinner) is 25'-9 1/2"; Length with constant-speed propeller and spinner is 26'-3 1/2". ***Track with oversized tires is 7'-11 1/2". SECTION IV CARE OF THE AIRPLANE OWNER FOLLOW-UP SYSTEM SECTION VI- OPTIONAL SYSTEMS ALPHABETICAL INDEX - ---4-1 4-10 SECTION V OPERATIONAL DATA 5-1 6-1 Index-1 40-4½" This manual describes the operation and performance of the Agwagon "A" with the standard 230 HP engine and the optional 300 HP engine. Equipment described as "Optional" indicates the equipment is optional on airplanes with the standard 230 HP engine. Some of this equipment is standard on airplanes equipped with the optional 300 HP engine. *** 7'-10%' iii iv 4 Section I OPERATING CHECK LIST 25 EXTERIOR INSPECTION a. Turn master switch "ON" and check fuel quantity indicator(s), then turn master switch off. Check magneto switches "OFF." Check fuel shut-off valve knob "ON" (full b. c. in). d. Same as 4b, if optional wing tank fuel system is installed. (4) d. NOTE Visually check filler caps, in- spection plates and removable panels for security, and general condition of aircraft and ag- ricultural equipment during walk-around inspection. Section I lists, in Pilot's Check List form, the steps necessary to operate the airplane. For a more comprehensive description of opera- ting details and the airplane's equipment, systems, and controls, refer to Section II. All airspeeds given in Sections I, II and III are indicated airspeeds unless otherwise noted. BEFORE STARTING THE ENGINE. (1) Exterior Inspection (2) Seat and Seat Belts -- Check. Adjust and lock. (3) Brakes -- Test and set. (1) Mixture -- Rich. -- "ON." " Off. b. c. istics will result.) Check fuel vent for stoppage if aircraft is equipped with optional wing fuel tank system. Check propeller for nicks, oil leaks, and security. On first flight of day and after each refuel- ing, pull out strainer drain knob for about four seconds, to clear fuel strainer of possi- ble water and sediment. Check valve closed after draining. Check oll level. Do not operate on less than 9 quarts. Fill for extended flights. Check oil filler cap secure. Check fuel vent for stoppage (on aircraft with standard fuselage fuel tank system). Same as 3. Remove pitot tube cover, if installed, and check pitot tube opening for stoppage. (4) Fuel Shutoff Valve "ON" (knob pushed full in). (5) Radio and Electrical Equipment STARTING THE 230 HP ENGINE. (2) Carburetor Heat -- Cold. (3) Propeller (if applicable) -- High RPM. (4) Master Switch (5) Magneto Switches "ON." (6) Primer (7) Throttle (8) Starter 11 -- -- As required in cold weather. Cracked (after pumping twice). Engage. STARTING THE 300 HP ENGINE. (1) Mixture -- - Rich. (2) Propeller -- High RPM. (3) Throttle -- Closed. e. 1. نون Release control lock, if installed (opt). Check all items in cockpit secured, con- trol cables clear of obstructions. 2 a. b. c. d. MAINN Remove rudder gust lock, if installed. Disconnect tall tie-down. Check tail wheel tire for proper inflation. Check static source holes on each side of tailcone for stoppage. d. 3 a. Disconnect wing tie-down. D. c. Check main wheel tire for proper inflation. Check wing strut outboard fairings for damage and security. (Never fly with fair- ings removed as adverse stall character- (6) a. Figure 1-1. 1-1 (5) Brakes -- Release. (4) Master Switch "ON." -- (5) Magneto Switches "ON." (6) Auxiliary Fuel Pump Switch "START." -- Engage. 71 (7) Starter (8) Very slowly advance throttle until engine starts. (9) Auxiliary Fuel Pump Switch "OFF." BEFORE TAKE-OFF. (1) Flight Controls Check. -- (6) Elevator Control -- Lift tail wheel and assume level flight attitude for best acceleration. (7) Climb Speed -- 75 to 85 MPH until all obstacles are cleared. (8) Wing Flaps Retract after obstacles are cleared. CLIMB. -- NORMAL CLIMB (Without Dispersal Equipment). (1) Airspeed - -- 85 to 95 MPH. (2) Power -- 23 inches and 2450 RPM for 230 HP engine or 25 inches and 2550 RPM for 300 HP engine. (3) Mixture -- Lean for altitude. MAXIMUM PERFORMANCE CLIMB (Without Dispersal Equipment). (1) Airspeed 88 MPH. -- (2) Elevator Trim Tab -- Set. (3) Canopy Doors -- Closed. -- (4) Throttle Setting 1700 RPM. (5) Engine Instruments Check. -- (6) Carburetor Heat (230 HP Engine) -- 13 Check operation. (7) Magnetos Check (50 RPM maximum differential between magnetos). (8) Propeller (if applicable) -- Cycle from high to low RPM; return to high RPM (full in). (9) Wing Flaps TAKE-OFF. -- 0 to 20°. NORMAL TAKE-OFF. (1) Wing Flaps -- 10°. (2) Power Full throttle and: -- 2600 RPM for 230 HP engine, 2850 RPM for 300 HP engine. (3) Elevator Control -- Lift tail wheel and assume level flight attitude for best acceleration. (4) Climb Speed -- 70 to 80 MPH. (5) Wing Flaps -- Retract. RESTRICTED CATEGORY TAKE-OFF (Dispersal Equipment Installed). (1) Wing Flaps 10°. 11 Apply. Full throttle and: (2) Brakes (3) Power 2600 RPM for 230 HP engine, 2850 RPM for 300 HP engine. (4) Mixture Lean for field elevation (300 HP engine). 1-2 (2) Power -- Full throttle and: (3) Mixture 2600 RPM for 230 HP engine, 2700 RPM for 300 HP engine. Lean for altitude. NOTE The climb speeds listed above in "Normal Climb" and "Maximum Performance Climb" check lists will decrease approximately 13 MPH with dispersal equipment installed. BEFORE LANDING. (1) Mixture -- Rich. Apply before closing throttle. (2) Carburetor Heat (230 HP Engine) (3) Propeller (if applicable) -- High RPM. (4) Airspeed-- 80 to 90 MPH (flaps up). (5) Wing Flaps -- As desired. (6) Airspeed-- 75 to 85 MPH (flaps down). NOTE Increase the above listed airspeeds by 5 MPH if landing at maximum RESTRICTED CATEGORY weight. 1-3 AFTER LANDING. (1) Wing Flaps -- Up. (2) Carburetor Heat (if applicable) SECURE AIRCRAFT. -- Cold. (1) Mixture Idle Cut-Off (pulled full out). (2) All Switches-- Off. (3) Brakes-- Set. (4) Control Lock-- Attached. 1-4 Section II DESCRIPTION AND OPERATING DETAILS The following paragraphs describe the systems and equipment in the airplane. Operating procedures that are not obvious are described in de- tail. ENGINE CONTROLS. The throttle is the outboard lever in the control quadrant located on the left side of the cockpit (figure 2-1). Friction on the control may be increased by rotating the knurled knob on the control quadrant in a clock- wise direction. The mixture control (230 HP Engine) is a conventional double-button type push-pull control, located just aft of the throttle quadrant. To pro- vide full rich mixture, push the control full in. To lean the mixture, squeeze the two buttons together and pull the control out to the desired position. A push-pull mixture control with a vernier feature is used for the 300 HP engine. For precise mixture adjustments, screw the control in or out to the desired position. For larger adjustments, depress the thumb button and push or pull the control as desired. The full-out position of the control is the idle cut-off position. The conventional push-pull type carburetor air control (230 HP Engine) is located on the lower left side of the instrument panel. This control actu- ates a butterfly valve in the carburetor air box which selects the source of engine induction air (figure 2-2). Pulling the control to the full-out posi- tion cuts off the flow of filtered ram air to the carburetor and causes non- filtered, heated air to be ducted to the carburetor. The carburetor air control should be in the full-in position for normal operation, except dur- ing power-off or low-power descents. In atmospheric conditions that are conducive to carburetor icing, select the minimum amount of carburetor heat for normal operation that will keep ice cleared from the carburetor. 2-1 COCKPIT CONTROLS and 5 6 7 8 9 $1 INSTRUMENT PANEL 2 3 4 5 6 8 9 10 11 19 18 17 16 15 14 13 12 1. Left Switch and Control Panel 11. Right Switch and Control Panel 2. Circuit Breakers 12. Emergency Cockpit Door Release Handle 3. Liquid Measure Conversion Table (One on Each Side of Cockpit.) 21 20 19 18 17 16 15 14 13 12 11 10 4. Airspeed Indicator 13. Fan Brake Control 5. Altimeter 14. Control Stick 6. Turn-and-Bank Indicator (Opt.) 15. Right Cockpit Heat Outlet Turn Coordinator (Opt.) 16. Right Rudder Pedal 7. 1. Spray Valve Control Handle Adjustment Knob 2. Spray Valve Control Handle 11. Radio 12. Left Rudder Pedal 3. Throttle 13. Left Cockpit Heat Outlet 4. Ash Tray 14. 5. Spray Pressure Gage 15. Wing Flap Control Handle 6. Manifold Pressure Gage (230 HP Engine, CSP) 16. Pilot's Seat Manifold Pressure Gage/Fuel Flow Indicator (300 HP Engine) 17. Friction Control Knob 7. Tachometer 18. Propeller Control (CSP Engines Only) 8. Fuel Quantity Indicator 19. Hopper Control Crank 2-1. 9. Instrument Panel and Radio Dial Light Control Knobs 20. Engine Mixture Control 10. Microphone 21. Elevator Trim Tab Control Wheel Cylinder Head Temperature Gage (Opt.) 17. Parking Brake Handle 8. Oil Pressure Gage 18. Fresh Air Outlet 9. Oil Temperature Gage 19. Hopper Quantity Indicator Markings Hopper Control and Dump Handle 10. Ammeter 2-2 Figure 2-3 2-4 INDUCTION AIR SYSTEM Schematic 230 hp ENGINE INDUCTION. AIR FILTER INDUCTION- AIR DUCT ENGINE EXHAUST CONTROL FULL IN 音 INDUCTION AIR SYSTEM Schematic 300 hp ENGINE Q HEAT SHROUD CARBURETOR CARBURETOR AIR CONTROL COOLING GILLS INDUCTION- AIR FILTER CARBURETOR- AIR BOX -BUTTERFLY VALVE CODE ➡ FILTERED INDUCTION AIR HEATED AIR ENGINE COOLING AIR MECHANICAL CONNECTION INDUCTION. AIR FILTER INDUCTION. AIR DUCT ENGINE- EXHAUST 4 THROTTLE 4 P. BODY NORMAL OPERATION COOLING GILLS INDUCTION AIR DUCT SPRING LOADED VALVE DOORS CLOSED CODE ENGINE COOLING AIR FILTERED INDUCTION AIR ALTERNATE SOURCE INDUCTION AIR CONTROL FULL AIR- PASSAGE BLOCKED 4 * THROTTLE 4 BODY HEAT SHROUD CARBURETOR- OUT CARBURETOR AIR CONTROL COOLING GILLS OR RESTRICTED INDUCTION. AIR FILTER INDUCTION AIR DUCT CARBURETOR AIR BOX BUTTERFLY VALVE Figure 2-2. 4 Figure 2-3. ALTERNATE SOURCE OPERATION COOLING GILLS SPRING LOADED VALVE DOORS OPEN 2-5 The propeller control lever (230 HP Engine, CSP, and 300 HP Engine) is the inboard lever on the control quadrant located on the left side of the cockpit. The full forward position gives "INCREASE RPM." IGNITION SWITCHES. Two separate toggle-type magneto ignition switches are located on the lower left side of the instrument panel. Each switch is "ON" in the up po- sition and "OFF" in the down position. Operation of the ignition system is conventional. The left ignition switch controls the left magneto which fires the top spark plugs on the left bank of cylinders and the bottom spark plugs on the right bank. Conversely, the right ignition switch controls the right magneto which fires the top spark plugs on the right bank and the bottom spark plugs on the left bank. ENGINE PRIMER (230 HP Engine.) A conventional plunger-type engine primer is located on the lower left side of the instrument panel. Approximately 2-6 strokes of the primer (prior to depressing the starter button) will provide the proper fuel mix- ture for starting a cold engine. In hot weather, pumping the throttle one or two strokes may be performed in lieu of engine priming. The primer knob should be full in and locked when not in use to prevent the engine from drawing fuel through the primer system (see figure 2-5). ENGINE PRIMER (300 HP Engine). Refer to "Auxiliary Fuel Pump Switch" paragraph in this section. STARTER BUTTON. A push-button starter switch is located on the lower right side of the in- strument panel. The starter system operates in the same manner whether power is being supplied by the aircraft battery or an external power source. ENGINE INSTRUMENTS. TACHOMETER. A mechanically-driven recording tachometer is located in the instru- ment console on the instrument panel deck. The recorder is set to record engine time accurately for the particular engine and propeller combination on the airplane. For an explanation of the engine instrument markings shown on the tachometers, refer to Section III. MANIFOLD PRESSURE GAGE/FUEL FLOW INDICATOR. A manifold pressure gage is provided when the airplane is equipped with a 230 HP engine and constant-speed propeller. If the airplane has a 300 HP engine and constant-speed propeller, a combination manifold pressure/fuel flow indicator is provided. On this instrument, manifold pressure is shown on the left side of the instrument face, and fuel flow is shown on the right side. The fuel flow indicator senses fuel pressure developed at the fuel distribution valve (figure 2-6), and is calibrated in gallons per hour. Fuel flows required to give adequate engine cooling in full throttle climbs are shown on a placard near the fuel flow indicator. PROPELLER. A 90-inch aluminum, fixed-pitch, two-bladed propeller is standard equipment on the 230 HP engine. This propeller has a relatively flat pitch to permit high RPM (and power) at take-off and climb speed. An 88-inch constant speed, two-bladed propeller is optional on the 230 HP engine. An 86-inch constant speed, two-bladed propeller is provided as part of the 300 HP engine installation. On aircraft having constant speed propellers, a propeller governor maintains a selected RPM regardless of varying airspeeds or flight atti- tudes when sufficient engine power is being developed. The governor in- creases the propeller blade angle by directing pressurized engine oil to a piston in the propeller hub. Conversely the aerodynamic forces acting on the propeller blades and an internal spring cause the blades to move to low pitch when the propeller lever is moved to the "INCREASE RPM" position. OIL SUPPLY SYSTEM. Oil for engine lubrication and propeller governor operation is supplied from a sump located at the bottom of the engine. Oil is picked up by the engine-driven pump, and is pumped through the engine oil filter screen (or 2-7 2-6 2-8 - OIL SYSTEM SCHEMATIC NOTE On airplanes equipped with a fixed-pitch propeller, a plate is installed instead of the propeller governor. This plate "dead ends" the propeller governor inlet oil gallery. Also, a plug is installed in the engine crankshaft to prevent oil leakage. PROPELLER CONTROL LEVER PROPELLER GOVERNOR OIL FILLER CAP OIL PRESSURE GAGE OIL DIPSTICK- SUMP DRAIN PLUG- PRESSURE OIL SUMP OIL, RETURN OIL, AND SUCTION OIL ENGINE OIL PUMP THERMOSTAT (OPEN) TO PROPELLER THERMOSTAT (CLOSED) OIL COOLER ENGINE & ACCESSORY] BEARINGS OIL PRESSURE RELIEF VALVE OIL PUMP BYPASS VALVE ENGINE OIL FILTER SCREEN FILTER BYPASS VALVE OIL TEMPERATURE GAGE the optional oil filter) through the right oil gallery to the thermostat. When the temperature of the oil is below 150°, the thermostat causes the oil to bypass the oil cooler. As the temperature rises above 150°, the thermo- stat closes, causing the oil to be forced through the oil cooler. From the thermostat and oil cooler, the oil is directed to various engine lubrication passages and the propeller governor and back to the sump. The capacity of the engine oil sump is 12 quarts. One additional quart is required if the optional oil filter is installed. However, the oil level should never be higher than the 12-quart mark on the dipstick. Refer to inside back cover for service information. FUEL SYSTEM. Fuel from the standard fuselage fuel tank system is supplied to the en- gine from a 37-gallon aluminum tank located just aft of the engine com- partment firewall. The tank is enclosed in a plastic vapor barrier bag equipped with three drain tubes equally spaced across the bottom of the fuel tank. The tank is vented from the filler neck through a vent line routed to a point under the left side of the fuselage ahead of the landing gear attach structure. In addition, small bleed holes are located in the internal por- tion of the fuel filler cap to provide tank venting if the main fuel vent be- comes obstructed. When the Fuel flows from the tank to a shutoff valve beneath the tank. shutoff valve is open and the mixture control is in the rich position with the engine running, fuel flows by gravity through the fuel strainer to the carbu- retor on 230 HP airplanes. On 300 HP airplanes, fuel is drawn through a check valve in the auxiliary fuel pump, through the fuel strainer to the en- gine-driven fuel pump, where it is pumped into the fuel metering unit. In the metering unit, fuel is regulated by the setting of the throttle and mix- ture controls. The metered fuel is pumped through the fuel distribution valve to the injection nozzles. The remainder of the unmetered fuel is re- turned to the engine-driven fuel pump where excess fuel and vapor are di- rected through a return line to the top of the fuel tank. For operation of the auxiliary fuel pump, refer to the "Auxiliary Fuel Pump Switch" para- graph in this section. An optional wing tank fuel system is available for aircraft having the 300 HP engine. Refer to Section VI for discussion of this system. FUEL SHUTOFF VALVE KNOB (Reference Figures 2-5 and 2-6). The double-button fuel shutoff valve knob, located on the right side CODE: OPTIONAL EXTERNAL FILTER Figure 2-4. 2-9 2-10 - FUEL SYSTEM SCHEMATIC 230 hp Engine FILLER CAP STRAINER DRAIN KNOB THROTTLE LEVER MIXTURE CONTROL KNOB FUEL QUANTITY. SCREEN' TRANSMITTER FUEL SHUTOFF VALVE RAM AIR SHUTOFF VALVE KNOB - FUEL STRAINER ENGINE PRIMER TO ENGINE CYLINDERS FUEL QUANTITY INDICATOR C CODE TO ENGINE CARBURETOR ☐ FUEL SUPPLY Figure 2-5. VENT MECHANICAL LINKAGE ELECTRICAL CONNECTION 30 25 FUEL SYSTEM SCHEMATIC 300 hp Engine FILLER CAP FUEL QUANTITY INDICATOR 12 SCREEN FUEL QUANTITY. TRANSMITTER VENT CHECK VALVE FUEL SHUTOFF VALVE SHUTOFF VALVE KNOB AUXILIARY FUEL PUMP STRAINER FUEL PUMP SWITCH STARTER SWITCH TO OEMERO OFF BUS Q FUEL STRAINER START THROTTLE SWITCH (ADVANCED TO BUS POSITION) TO STARTER DRAIN KNOB MIXTURE CONTROL KNOB ENGINE FUEL PUMP FILTER SCREEN 00 FUEL FUEL UNIT AIR THROTTLE DISTRIBUTION VALVE FUEL NOZZLE SOLENOID THROTTLE LEVER CODE FUEL SUPPLY VENT EXCESS FUEL AND VAPOR RETURN FUEL MECHANICAL LINKAGE ELECTRICAL CONNECTION O O ELECTRICAL SCHEMATIC FUEL FLOW INDICATOR Figure 2-6. 2-11 of the instrument panel, is connected by a push-pull control to a conven- tional two-position on-off valve beneath the fuel tank. The valve is open when the knob is pushed full in. To close the valve, depress the button on the end of the knob and pull the knob full out. The valve is normally left "ON" except during maintenance work involving fuel system components or during prolonged storage periods. AUXILIARY FUEL PUMP SWITCH (300 HP Engine). The auxiliary fuel pump switch is a three-position toggle switch lo- cated on the right side of the instrument panel. The positions of the switch are labeled "EMERGENCY," "OFF" and "START." The "START" (down) position of the switch is used for starting. With the switch in the "START" position and the starter button depressed, the auxiliary fuel pump will erate at a low flow rate (providing proper mixture for starting) as the en- gine is being turned over for starting. NOTE The auxiliary fuel pump will not operate with the switch in the "START" position except when the starter button is being depressed (reference figure 2-6). op- The "EMERGENCY" (up) position of the switch is used for engine op- eration if the engine-driven fuel pump should fail. When the switch is in this position the pump operates at one of two flow rates, depending upon the setting of the throttle. When the throttle is at a cruise setting, the pump operates at maximum capacity, supplying sufficient fuel flow to maintain power. When the throttle is retarded (as during let-down and landing) the auxiliary fuel pump flow rate is automatically reduced, thus preventing excessively rich mixture during periods of reduced engine speed. The auxiliary fuel pump switch should not be placed in the "EMER- GENCY" position for normal operation, because, with the engine-driven fuel pump functioning, the additional output of the auxiliary fuel pump will provide a fuel/air ratio considerably richer than best power mixture. However, if fuel vapor is affecting engine operation, the vapor may be purged by placing the switch in the "EMERGENCY" position while lean- ing the mixture as required to prevent excessively rich mixture. Suc- cessful vapor purging is evidenced by smooth engine operation and steady and normal fuel flow indications with the auxiliary fuel pump switch "OFF." 2-12 NOTE If the auxiliary fuel pump switch is accidentally moved to "EMERGENCY" with the engine stopped (master switch "ON" and mixture forward of the idle cut-off When position) the intake manifold will be flooded. the manifold is flooded in this manner, engine starts should not be attempted until the excess fuel has drained from the manifold. STRAINER DRAIN CONTROL KNOB. A strainer drain control knob is located inside the left engine cowl access door on aircraft equipped with the standard fuselage fuel tank. It is connected to the strainer drain valve at the bottom of the firewall with a conventional push-pull control. When the knob is pulled out, the valve is opened and water and sediment, if any, will be drained from the strainer. The knob should be pushed full-in to close the strainer drain valve. After draining, a visual check should be made for water and sediment and to make sure the valve is closed. ELECTRICAL SYSTEM (Reference Figure 2-7). Electrical energy is supplied by a 14-volt, direct-current system or an optional 28-volt, direct-current system which is discussed in Section VI, Optional Systems. The 14-volt system consists of a 60-ampere engine-driven alternator, and a 12-volt, 25 amp-hour battery or an op- tional 12-volt, 33 amp-hour battery. The battery serves as the basic power source when the alternator is inoperative or when the alternator is not supplying sufficient current to meet the requirements of the electrical system. The alternator supplies current to the electrical system when the master switch is "ON," the engine is running, and the ammeter is not showing a discharge. The alternator is capable of producing 25 amperes at idle speed, making it far superior to a generator in keeping the battery charged in typical agricultural flight operations. The battery is located aft of the firewall on the right side of the fuse- lage. Access to the battery box is obtained by opening the right forward fuselage panel. CIRCUIT BREAKERS AND FUSES. Most of the electrical circuits in the airplane are protected by "push- 2-13 2-14 ELECTRICAL SYSTEM REGULATOR ALTERNATOR MASTER SWITCH GEN FLD BATTERY BATTERY CONTACTOR GROUND SERVICE PLUG RECEPTACLE (OPT) MAGNETOS ㄴ R MAGNETO SWITCHES GEN SCHEMATIC 20 TO LANDING LIGHTS (OPT) LOG LIGHTS 20 TO TAXI LIGHTS (OPT) TAXI LIGHTS TO NAVIGATION LIGHTS (OPT) 3 10 TO FLASHING BEACON (OPT) NAV LIGHTS B CIGAR LIGHTER WITH CIRCUIT BREAKER (OPT) U BCN LIGHT S AMMETER B STARTER STARTER CONTACTOR STARTER BUTTON AR TO INSTRUMENT LIGHTS CIRCUIT BREAKER *FUEL EMER PUMP TO FUEL PUMP SWITCH OFF START CIRCUIT BREAKER TO OPTIONAL TURN & BANK INDICATOR OR OPTIONAL TURN COORDINATOR TO STALL WARNING SYSTEM TO COMPASS, MAP, & INSTRUMENT LIGHTS (OPT) ⑩TO FUEL QUANTITY INDICATOR(S) INST TO CYL. HEAD TEMP GAGE (OPT) LIGHTS LTO STARTER BUTTON TO RADIO (OPT) RADIO TO FUEL PUMP SWITCH FUEL PUMP + CODE. CIRCUIT BREAKER (PUSH-RESET) FUSE (IN-LINE) DIODE *THROTTLE SWITCH CAPACITOR FUEL PUMP M RESISTOR *300 HP ENGINE ONLY to-reset" circuit breakers mounted on the instrument panel. The optional cigar lighter is protected by a manually reset circuit breaker mounted on the back of the lighter behind the instrument panel. A fuse mounted near the battery protects the battery contactor closing circuit. AMMETER. " The ammeter indicates the flow of current, in amperes, from the alternator to the battery or from the battery to the aircraft electrical system. When the engine is operating and the master switch is "ON, the ammeter indicates the charging rate applied to the battery. In the event the alternator is not functioning or the electrical load exceeds the output of the alternator, the ammeter indicates the discharge rate of the battery. LANDING LIGHTS (OPT). A three position, push-pull switch controls the optional landing lights. To turn the taxi lights on, pull the switch out to the first stop. To turn the landing lights on, pull the switch out to the second stop. To turn both taxi and landing lights off, push the switch full in. FLIGHT CONTROL SYSTEMS. The primary flight control surfaces (ailerons, elevator, and rudder) are controlled by a conventional control stick and rudder pedal arrange- ment. A bobweight is mounted on the control stick to give larger control pressure variation with changes in airspeed and flight load factors. The elevator trim tab is controlled by a wheel located to the left of the pilot's seat. Rolling the top of the trim wheel aft produces more nose up trim. WING FLAP SYSTEM. The wing flaps are manually operated by means of a lever located to the left of the pilot's seat. The lever provides locked positions for 0°, 10° and 20° of flap deflection. The flaps may be set in any one of the three positions by depressing the button on the end of the lever while moving the lever to the desired position. LANDING GEAR SYSTEM. The landing gear has been specifically designed for heavy-duty agri- 2-15 Figure 2-7. cultural dispersal service. It consists of extra thick chrome-vanadium steel main landing gear springs and a spring-steel tubular tailwheel spring with a steerable tailwheel. The tailwheel steering arms are connected to the rudder cables with cables and springs. Tailwheel steering of 24° left and right is available. For tighter turns in close quarters, application of toe pressure on either of the rudder pedals will cause the tailwheel to free swivel and enable the airplane to be pivoted around the wheel being braked. BRAKE SYSTEM. The hydraulic brakes on the main wheels are conventionally operated by applying toe pressure to the top of the rudder pedals. The rotation of the pedals actuates the brake master cylinders, resulting in braking action on the main wheels. The brakes may also be set by pulling the parking brake "T" handle aft. To release the parking brake, depress the button in the center of the "T" handle, and push it toward the instrument panel. PILOT'S SEAT. The standard pilot's seat is adjustable in a fore and aft direction and has an adjustable seat back tilt angle. An optional seat is available with standard seat adjustments plus a vertical height adjustment. This seat may be raised or lowered by turning the crank located below the front right corner of the seat bottom. Both the standard and optional seat are moved fore and aft by pulling up on the seat adjustment lever, located just forward and below the left front corner of the seat bottom, and sliding to the desired position. The lever is then released and the seat is moved fore or aft until the locking pin engages a hole in the seat track. Adjusting the seat back to the de- sired tilt angle is accomplished by leaning forward to remove pressure from the seat back, pulling up on the lever located on the right aft side of the seat near the hinge line, leaning back to the desired angle, and releasing the lever. Seat belts and a double-strap shoulder harness are provided. The lower ends of the shoulder harness are attached permanently to the seat belt. The length of the shoulder harness is easily adjusted by means of metal adjusters located at chest height. 2-16 COCKPIT PRESSURIZATION. Cockpit pressurization is provided to help keep dry application mate- rials from contaminating the cockpit. The system consists of adjustable pressure scoops located on each baggage door. The scoops are ground adjustable and can be positioned for varying amounts of pressurization. The full open position will provide maximum pressurization. For dusting operations, tailcone pressurization can be obtained by removing the panel behind the pilot's seat, with the pressure scoops full open. The pressure scoops can be used to give increased cockpit ventilation as well as pres- surization by opening the scoops and the optional foul weather windows. STARTING ENGINE (230 HP Engine). Ordinarily the engine starts easily after pumping the throttle one or two strokes. In cold weather, it is necessary to use 2-6 strokes of the primer with the throttle open approximately 1/2 inch. In extremely cold temperatures, it may be necessary to continue priming while cranking. Weak intermittent firing followed by puffs of black smoke from the exhaust stack indicates over-priming or flooding. Excess fuel can be cleared from the combustion chambers by the following procedure: Set the mixture control full lean and the throttle full open; then crank the en- gine through several revolutions with the starter. Repeat the starting procedure without any additional priming. If the engine is underprimed (most likely in cold weather with a cold engine), it will not fire at all. Additional priming will be necessary for the next starting attempt. If prolonged cranking is necessary, allow the starter motor to cool at frequent intervals, since excessive heat may damage the armature. STARTING ENGINE (300 HP Engine). Proper fuel management and throttle adjustments are needed to obtain an easy start from your continuous-flow fuel-injection engine. The pro- cedure outlined in Section I should be followed closely as it is effective under nearly all operating conditions, including hot and cold weather con- ditions. Slight variations from this procedure may be necessary at times to compensate for extreme conditions. 2-17