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climbing airspeed has been reached to achieve maximum rate of climb. The best rate of climb airspeed at gross
load is 55 MPH. At lighter weights, the best climbing airspeed will be reduced proportionally.
The gross weight power off stalling speed with full flaps in the Grizzly Cub 150 is 28 MPH IAS; with flaps up the
stalling speed increases about 3 MPH.
CRUISING
The cruising speed of the Grizzly Cub at 75% of rated engine power, at gross load under standard sea level
conditions, is approximately 105 M PH. Cruising airspeed and engine RPM will depend on the propeller installed on
the airplane.
Normally the Grizzly Cub should cruise at 2400 to 2450 RPM, but the 75% of power RPM (low altitudes) can be
determined as follows:
1.
Fly the aircraft as near sea level as practicable at full throttle until maximum speed is reached. Note RPM
at top speed, level flight.
2.
Reduce the maximum RPM by 10% and cruise at 90% of full RPM. The correct cruising RPM will result in a
cruising airspeed of 105 MPH with a fuel consumption of approximately 9 gallons per hour. If the airplane is slowed
down to about 85 MPH, approximately 5 gallons per hour will be used. See fuel consumption chart.
The metal propeller with which the Grizzly Cub 160 is equipped as standard equipment is, unless specified
otherwise, a 56 inch pitch propeller that favors takeoff and climb rather than cruising speed. For training and other
purposes which do not require use of full power settings to obtain satisfactory performance, this propeller may be
operated, during takeoff, climb, and cruise, at 2200 RPM or less. This will still provide more performance than was
formerly available in 65 HP trainers, and will reduce fuel consumption and engine wear very appreciably.
The fuel consumption chart should be consulted to determine most economical cruising RPM for specific
requirements.
To lean the mixture, pull the mixture control until the engine becomes rough, indicating that the lean mixture limit
has been reached in the leaner cylinders. Then enrich the mixture by pushing the control toward the instrument
panel until engine operation becomes smooth. The mixture should be leaned when 75% power or less is being
used. If any doubt exists as to the amount of power being used, the mixture should be in the FULL RICH position
for all operations. Always enrich the mixture before increasing power settings. Use of the mixture control in
cruising flight reduces fuel consumption significantly, especially at higher altitudes, and reduces lead deposits
when the alternate fuels are used.
Unless icing conditions in the carburetor are severe, do not cruise with the carburetor heat on. Apply full
carburetor heat only for a few seconds at intervals determined by icing severity.
APPROACH AND LANDING
During the approach, trim the plane with the stabilizer adjustment until no force is required on the stick to
maintain a gliding speed of 70 MPH. Lower the flaps at an airspeed not to exceed 85 MPH. The mixture should be
full rich, fuel valve on correct tank. The carburetor heat need not be used unless icing conditions prevail, but the
engine should be cleared frequently by opening the throttle.
During the landing roll the steerable tail wheel should be used for directional control, and brakes should be used as
little as possible to avoid excessive brake and tire wear.
