Operations Manual
Coot A



Section I Operating Check List




Exterior Inspection

1. (a) Turn on master switch and check fuel quantity.

(b) Ignition switch = OFF

(c) Check airspeed static hole on side of the hull for obstructions.

2. (a) Check oil level. Do not operate with less than 6.5 quarts of oil. Fill for extended flights.

(b) Check propeller, cooling fan and spinner for nicks, cracks and security.

(c) Check pitot tube opening for obstruction.

(d) Check carburetor air filter for restriction.

(e) Check engine and pylon for security and for fuel and oil leaks.

3. (a) Check main tire for proper inflation.

4. (a) Disconnect wing tie-down.

5. (a) Check aileron hinge points for security.

(b) Remove aileron gust lock if installed.

6. (a) Check fuel cap for security.

(b) Check fuel tank vent opening and opening in the fuel cap for obstructions.

7. (a) Remove rudder and elevator gust locks if installed.

(b) Check rudder and elevator hinge points for abnormal wear.

(c) Disconnect tail tie-down.

8. (a) Check aileron hinge points for security.

(b) Remove aileron gust lock if installed.

9. (a) Disconnect wing tie-down.

10. (a) Check main tire for proper inflation.

11. (a) Check airspeed static hole on side of fuselage for obstruction.

(b) Pull fuel strainer knob to clear fuel strainer of water, If installed, remove plug from fuel drain in the bottom of the hull.

12. (a) Check nose wheel tire for proper inflation.


Before Starting Engine

  • (1) Adjust seat belts and shoulder harness.

    (2) Test brakes.

    (3) Fuel valve = ON

    (4) All switches = OFF

    (5) Landing gear operator = LOCKED

    (6) Circuit breakers = IN


    Starting Engine

  • (1) Carburetor heat = COLD

    (2) Mixture = RICH

    (3) Master switch = ON

    (4) Turn on electric fuel pump. Minimum pressure should be 4 PSI.

    (5) Pump throttle to prime engine as required. If required, prime engine with engine primer.

    (6) Throttle = 1/4 OPEN

    (7) Propeller area = CLEAR

    (8) Ignition switch to START. Release switch when engine starts.

    (9) If oil pressure is not up in 10 seconds, shut down the engine.

    (10) Alternator switch = ON

    Oil pressure at idle is approximately 25 PSI.

    Oil pressure at cruise RPM is 75 to 85 PSI.

    Normal operating oil temperature is 165-230 degrees F.

    (11) Radio = ON

    (12) Rotating beacon = ON



  • Before Take-Off

  • (1) Mixture = RICH

    (2) Throttle = 1700 RPM

    (3) Oil pressure = 60-75 PSI

    (4) Fuel pressure = 2-5 PSI

    (5) Cylinder head temperature = 400 -500  F

    (6) Oil temperature IN THE GREEN

    (7) Voltmeter = 14 VOLTS

    (8) Ammeter = CHECK

    (9) Magnetos = 125 RPM DROP or 35 RPM DROP between magnetos.

    (10) Carburetor heat = CHECK OPERATION

    (11) Trim tab = TAKE-OFF setting.

    (12) Flight controls CHECK

    (13) Canopy LATCHED

    (14) Flight instruments SET



    Normal take-off

  • (1) Carburetor heat COLD

    (2) Throttle FULL OPEN

    (3) Elevator control LIFT NOSE WHEEL AT 50 MPH

    (4) Climb speed = 70-80 MPH

    (5) Landing gear AS DESIRED



  • Landing


  • (1) Approach Airspeed = 80 MPH

    (2) Landing gear DOWN AND LOCKED

    (3) Carburetor heat APPLY FULL HEAT UNDER 2,000 RPM

    (4) Landing Airspeed = 50-60 MPH



  • (1) Approach Airspeed = 80 MPH

    (2) Landing gear UP AND LOCKED !

    (3) Carburetor heat APPLY FULL HEAT UNDER 2,000 RPM

    (4) Touchdown Airspeed = 45-50 MPH


    Secure Aircraft

  • (1) Mixture IDLE CUT OFF

    (2) All switches OFF


  • Section II Operating Check List


    Fuel System




    Fuel is supplied to the engine from one fuel tank that is installed in the hull behind the main spar. The fuel is pumped to the carburetor by the electric or engine-driven fuel pump.



    Instrument Panel




  • (1) Start switch

    (2) Master switch

    (3) Airspeed

    (4) Altimeter

    (5) Tachometer

    (6) Radio

    (7) Magnetic compass

    (8) Rate of climb

    (9) Turn and bank

    (10) Throttle

    (11) Landing gear control

    (12) Landing gear locked light

    (13) Landing gear up light

    (14) Landing gear down light

    (15) Handle

    (16) Landing gear actuator

    (17) Landing gear motor disengage handle

    (18) Fuel pump (circuit breaker)

    (19) Beacon

    (20) Bilge pump

    (21) Alternator

    (22) Radio

    (23) Instruments

    (24) Landing gear

    (25) Panel lights (fuse)

    (26) Cylinder head temperature switch

    (27) Cylinder head temperature

    (28) Voltmeter

    (29) Fuel-oil pressure

    (30) Oil temperature

    (31) Fuel quantity

    (32) Carb heat

    (33) Mixture control

    (34) Speaker "on-off" switch

    (35) Speaker

    (36) Engine fuel primer

    (37) Landing gear motor control breaker

    (38) Landing gear lock-unlock operator

    (39) Misc. and headset jacks are located on left side of cabin

    (40) Nav lights (circuit breaker)

    (41) Cabin light


    Electrical System

    Electrical energy is supplied by a D.C. system powered by an engine-driven alternator. A 12-volt battery is located in the bow of the hull. The master switch controls all electrical circuits except engine ignition.

    The ammeter indicates the flow of current from the alternator to the battery or from the battery to the 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 fails, the ammeter will indicate the discharge rate of the battery.

    Circuit breakers and switch circuit breakers on the lower right side of the instrument panel protect the electrical circuits. The circuit breakers are to be pushed in to energize the circuits. When the circuit breaker switch handle is in the up position. the circuit is energized. Labeling below each circuit breaker indicates the circuit protected.


    Flashing Beacon

    The flashing beacon should not be used when flying through clouds or overcast. The flashing light reflected from water droplets in the atmosphere, particularly at night, can produce vertigo and loss of orientation.


    Ventilation System

    An adjustable ventilator in the pilot's overhead can be adjusted to provide fresh air as needed.


    Parking Brake System

    To set the parking brake, apply brake pressure and pullout the parking brake knob. Push in the parking knob to release the brakes.


    Landing Gear System


    The landing gear system is operated by positioning the landing gear control as desired. When the landing gear control is positioned for retraction or extension, an electrical motor drives a jack screw that moves the linkages that retract or extend the landing gears. The landing gear locks are engaged by the landing gear control. The landing gears are stopped at full retraction or extension by limit switches. If motor failure occurs. the pilot can manually disengage the motor and hand crank the landing gears to the desired position. Landing gear position lights and the motor 15 amp circuit breaker are located on the landing gear position panel.



    The landing gear control is located on the left side panel near the instrument panel. Grip the handle and move it back and up to clear the detent. The handle will be perpendicular to the side panel. Move the handle to the desired landing gear position. Push the handle down and slightly forward so it is in the detent. When the landing gear position light is illuminated. move the handle slightly-back and up and return it to the locked position. push the handle down and slightly forward into the detent. The locked position light should illuminate.

    Should the landing gear electrical system fail, the landing gears can be retracted or extended as follows:

  • 1. Position the landing gear control to the desired position.

    2. Remove the jackscrew crank from the holder on the bottom of the landing gear position console.

    3. Insert the crank into the jackscrew.

    4. Firmly push the motor disengage handle in and slightly turn it to the left. The handle will remain in.

    5. Crank until the jackscrew is lined up with the desired position light.

    6. Move the gear control to the locked position.

  • Should the landing control not lock or unlock, accomplish the following:

  • 1. Position the Landing gear control out of the detent.

    2. Firmly grip the lock position indicator knob and move it to unlock or lock position.


    Starting The Engine

    The engine should start with one or two strokes of primer in warm temperatures, to six strokes in cold weather, with the throttle open about 1/4 inch. In extreme cold temperatures, it may be necessary to continue priming. If flooding occurs, excess fuel can be cleared from the cylinders by the following procedure:



    When taxiing, speed should be held to a minimum and all controls should be utilized in accordance with the above taxi diagram.

    The Coot has a free-swiveling nose wheel and the brakes are used to steer.


    Water Operations (General)

    The Coot A has excellent water performance and water handling characteristics. The proximity of the wing to the water develops a ground effect due to the wing tending to climb up on the effective wedge of air that is compressed slightly when the aircraft is taking off or landing and is close to water. This effect permits the aircraft to get up out of the water at unusually low speeds. On landing. the aircraft has a tendency to "float" just before touch-down and thus it slows appreciably before landing on water. With two people on board. take-offs in water are approximately 400 feet in light winds.

    The bilge area behind the seats should be periodically checked for water during extended water operations. Turn ON the bilge pump switch to remove the water. The landing gears can be extended to taxi from the water to the beach. Before the gears are retracted. taxi the aircraft in the water a few seconds to allow the nose wheel to line up with the nose wheel well.


    Before Take-Off

    Warm-up will normally be conducted during taxi. The engine is closely cowled and the cooling fan should preclude overheating during long taxi times and water operations. However, precautions should be taken to prevent over heating.


    Magneto Check

    The magneto check should be made at 1700 RPM. Move the switch to R and note the RPM. Move the switch back to BOTH. Then move the switch to L and note the RPM. Move the switch back to BOTH. The difference between the two magnetos should not be more than 35 RPM. The drop of each magneto should not exceed 125 RPM.

    An absence of RPM drop may be an indication of faulty grounding of one side of the ignition system or should be cause for suspicion that the magneto timing is set in advance of the specified setting.



    Check full-throttle engine operation early in the take-off run. Any signs of rough engine operation or sluggish engine acceleration is good cause for discontinuing the take-off. If this occurs, make a full-throttle static run-up. The engine should run smoothly at 2300 ± 50 RPM with the carburetor heat OFF and the mixture control in full rich.

    During strong crosswind take-offs. accelerate to speeds higher than normal, pull off abruptly to prevent possible settling back to the runway while drifting. When clear of the ground, make a coordinated turn into the wind to correct for drift.


    Climb Speeds

    Normal climbs are conducted 70-80 MPH with full throttle and the mixture control at full rich. The best rate of climb speeds range from _____MPH at sea level to ____ MPH at 10,000 ft. The best angle of climb speed is made with full throttle. These speeds vary from ____ MPH at sea level to ____ MPH at 10,000 ft.



    Normal cruising is done at 65% to 75% maximum engine take-off power.



    The stall characteristics are conventional. The stall should break straight ahead with little or no control inputs.

    Typical stall speeds are 48 to 53 mph, checked with a GPS.



    Normal landings are made with power off. Approach speeds are made at 75-80 MPH.


    Short Field Landings

    Make a power off approach at 58 MPH and land on the main wheels first. Upon touchdown, lower nose gear and apply heavy braking as required.


    Crosswind Landings

    Use wing low, crab or a combination method of drift correction and land in a nearly level attitude.


    Cold Weather Operation

    Prior to starting on cold mornings, pull the propeller through several times by hand to limber the oil. In extremely cold weather (0  F. and below) an external pre-heater is recommended to reduce wear on the engine and the electrical system.

    With preheat:

  • (1) Ignition switch OFF and the throttle closed, prime the engine for up to ten strokes as propeller is being turned by hand.

    (2) Use normal start procedure.

  • Without preheat:

  • (1) Prime the engine eight to ten strokes while the propeller is being turned by hand with the throttle closed. Leave primer charged and ready for stroke.

    (2) Clear propeller.

    (3) Master switch ON

    (4) Ignition switch to BOTH

    (5) Pump throttle rapidly to full open twice. Return to 1/4 inch position.

    (6) Engage starter and continue to prime engine until it is running smoothly, or alternately, pump throttle rapidly over first 1/4 of total travel.

    (7) Pull carburetor heat to full after engine starts. Leave on until engine is running smoothly.

    (8) Lock primer.

  • If the engine does not start during the first few attempts, or if engine firing diminishes, it is probable that the spark plugs are frosted over. Preheat must be used before another start is attempted.

    Pumping the throttle may cause raw fuel to accumulate in the intake air duct, creating a fire hazard in the event of backfire. If this occurs, maintain a cranking action to suck the flames into the engine. An outside attendant with a fire extinguisher is advised for cold starts without preheat.

    During cold weather operations, no indication will be apparent on the oil temperature gauge prior to take-off if outside temperatures are very cold. After a suitable warm-up period (2 to 5 minutes at 1,000 RPM), accelerate the engine several times to higher engine RPM. If the engine accelerates smoothly and the oil pressure remains normal and steady, the airplane is ready for take-off.

    When operating in sub-zero temperature, avoid using partial carburetor heat. Partial heat may increase the carburetor air temperature to 32  F to 70  F range, where icing is critical under certain atmospheric conditions.



    SECTION 3 Care of the Airplane


    Ground Handling

    The airplane is safely maneuvered by hand with a tow-bar attached to the nose wheel. When using the tow-bar, do not exceed the turning angle of the nose wheel in either direction. or damage to the gear can occur.


    Mooring The Airplane

    Tie down the airplane for strong crosswinds as follows:

  • (1) Set the parking brake.

    (2) Install a surface control lock between each aileron and wing edge.

    (3) Tie ropes or chains to wing and tail tie downs. The tensile strength of the ropes or chains should be a minimum of 700 PSI.

    (4) Install pitot tube cover.

    (5) Tie the stick back. using the seat belts.


    Windshield and Windows

    The Plexiglas windshield and windows should be cleaned with Plexiglas cleaner or scratch remover. Follow the instructions on the Plexiglas cleaner container. Do not use gasoline, benzene, alcohol, acetone, carbon tetrachloride, lacquer thinner or glass cleaner on Plexiglas. These chemicals will attack the Plexiglas and may cause it to craze.


    Painted Surfaces

    The painted surfaces can be washed with water and mild soap. Do not use harsh abrasive soaps or detergents. To keep the surfaces bright and protected from exposure to sun light. the airplane can be waxed with a good automotive wax. A heavy coat of wax on the leading edge of the wing and propeller, tail, and bow will reduce abrasion encountered in these areas.

    Standard solvent or any paint prep solvent can be used to clean up stubborn oil or grease.


    Propeller Care

    The Coot utilizes a variable-pitch propeller, usually of constant-speed type. Inspect the blades for pitting from water spray. Carefully file out pitting as required. Clean propeller with solvent to remove grass and bug stains.


    Interior Care

    Clean the interior regularly with a vacuum cleaner. Oil spots can be cleaned up with household cleaners. Do not use volatile chemicals such as those mentioned under the Windshield and Window care paragraph. The plastic trim and instrument panel need only be wiped off with a damp cloth.


    Inspection Service And Inspection Periods

    The FAA requires that all airplanes have a periodic (annual) inspection. The owner can perform the periodic inspection. However, the owner should be very familiar with maintenance procedures prior to attempting an annual inspection. A rated mechanic should be consulted to insure utmost safety.


    Aircraft File

    1. The following documents are to be displayed in the aircraft at all times:

  • (a) Passenger warning placard

    (b) Airworthiness Certificate (Form FAA -1362B)

    (c) Aircraft Registration Certificate (Form FAA -SOOA)

    (d) Aircraft Radio Station License (Form FCC -404)

  • 2. The following documents are to be carried at all times:

    (a) Weight and balance

    (b) Aircraft equipment list

  • 3. The following document is to be made available upon request:

    (a) Aircraft Log Book.


    Daily Servicing Procedures

    Fuel Tank

    Service after each flight with 100LL grade fuel.


    Fuel Strainer

    Before the first flight of the day and after refueling, pullout the fuel strainer knob (behind the passenger seat) for about four seconds to clear strainer of water or sediment.


    Oil Dipstick

    Check oil level before each flight. Service with aviation grade engine oil SAE-5O. Do not operate the aircraft with less than 6 quarts.


    Servicing Requirements

    Brake Fluid MIL-H- 5606 (Hydraulic Fluid)

    Tire Pressure: Mains - 45 PSI

    Nose 50 PSI

    Engine Oil: SAE-50

    Fuel: 100 LL

    Control Surface Bearing: Lubricant STP or equivalent

    Landing Gear Linkage: Lubricant STP or equivalent

    Landing Gear Motor Gear Box and Chain: Lubricant STP or equivalent

    Battery: 12V DC, 35 Ampere capacity


    Servicing Intervals

    Each 25 Hours

  • (1) Battery: check and service. It should be checked more often (at least every 30 days).

    (2) Engine Oil: Change oil and clean oil screen. Change oil every 4 months even though 25 hours have not accumulated.


    Each 50 Hours

  • (1) Accomplish items in 25 hour maintenance.

    (2) Carburetor Air Filter - Clean or replace.

    (3) Fuel Strainer - disassemble and clean.

    (4) Landing Gear Linkages - lubricate (oil)

    (5) Landing Gear Motor Gear Box and Drive Chain - lubricate (oil).

    (6) Landing Gear Operator Shaft - lubricate (grease).

    (7) Rudder Petal Bearings - lubricate.


    Each 100 Hours

    (1) Accomplish items in 50 hour maintenance.

    (2) Brake Master Cylinders : check and fill.

    (3) Fuel Tank Sump : remove and clean screen.

    (4) Spark Plugs : clean, test and re-gap.

    (5) Wheel Bearings : remove, clean and lubricate with grease.

    (6) Control Service Bearings : lubricate (oil).

    (7) Carburetor Fuel Screen : remove, clean, reinstall.

    (8) Grease nose wheel shaft.



    SECTION IV Weight and Balance


    Example Weight and Balance



    Scale position








    Net weight


    Left wheel










    Right wheel










    Nose wheel










    Aircraft empty weight as weight






    Moment = Weight ´ Arm










    Left wheel








    Right wheel








    Nose wheel













    Empty weight C.G. = Total moment ¸ Total weight


    C.G. =


    Total moment




    = E.W.C.G.




    Total weight




    (110" specified)


















    Pilot and passenger








    Gross weight








    Current Weight and Balance

    Serial Number_______________________________ N________________



    Scale position








    Net weight


    Left wheel






    Right wheel






    Nose wheel






    Aircraft empty weight as weight




    Moment = Weight ´ Arm










    Left wheel





    Right wheel





    Nose wheel









    Empty weight C.G. = Total moment ¸ Total weight


    C.G. =


    Total moment


    = E.W.C.G.


    Total weight

     (15% - 30 % M.A.C.)
















    Pilot and passenger





    Gross weight