GRUMMAN GOOSE G21a

A. PREFLIGHT CHECKS

[ ]  The airplane should be given a careful visual inspection prior to flight to ascertain that tires and shock struts are properly inflated, control surfaces are free, fuel tank caps tight, cowling and other openable parts are secure, and no obvious damage exists.

[ ] Propellers should be examined for nicks, tow bar stowed under the rear seat, and gascolators drained.

[ ] Upon entering the plane, the pilot should make sure that all controls operate normally, that the landing gear and other controls are in proper positions, and that the main door is firmly secured.

B. Starting

[ ] Before starting the engine, turn on the master battery switch.

[ ] When the engines are cold, prime three to five strokes, making sure fuel valves are on, fuel pressures normal and fuel quantity checked. Push mixture controls to full rich and carburetor heat off. If the engines are extremely cold, they should be pulled through by hand four to six times.

[ ] Turn all magneto switches on and engage starter on left engine first. After engine starts, idle at 800 to 1000 RPM and start right engine. If battery is low, before starting right engine, run left engine over 1200 RPM to cut in the generator. This will produce extra power for starting the right engine. If the engine does not start in the first few revolutions, open the throttle on that engine while the engine is turning over with the ignition on. When the engine starts, reduce the throttle. If the above procedure does not start the engine, re-prime and repeat the process. Continue to load cylinders by priming or unload by turning the engine over with the throttle open.

[ ] If the engine still doesn't start, check for malfunctioning of ignition or fuel system. When the engines are warm, do not prime, but turn magneto switches on before engaging starter. The engines should start after rotating through about four compression strokes.

C. Warm-up And Ground Check

[ ] As soon as the engines start, the oil pressures should be checked. If no pressure is indicated within thirty seconds, stop the engine and determine the trouble. Warm-up the engines at 800 to 1000 RPM for not more than two minutes in warm weather, four minutes in cold weather. If electrical power is needed from the generators, the engines can be warmed at 1200 RPM at which point the generator cuts in. The magnetos should be checked at 1400 RPM, the drop not to exceed 100 RPM. The engines are warm enough for take-off when the throttles can be opened without engine faltering.

[ ] Carburetor heat should be checked during the warm up to make sure the heat control operation is satisfactory and to clear out the carburetor if any ice has formed. It should also be checked in flight occasionally when outside air temperatures are between 20 degrees and 70 degrees to see if icing is occurring in the carburetor. In most cases when an engine loses manifold pressure without apparent cause, the use of carburetor heat will correct the condition.

[ ] The propeller controls should be moved through their normal ranges during the warm-up to check for proper operation, then left in the full low pitch positions. Feathering checks on the ground are not recommended, because of the excessive vibration caused in the power plant installations.

[ ]Mixtures should be set full rich, except a minimum amount of leaning is permitted for smooth engine operation when taking off at high elevation.

D. Take-Off, Climb And Stalls

Just before takeoff the following should be checked:

[ ] 1. Controls free.

[ ] 2. Flaps up.

[ ] 3. Trim set.

[ ] 4. Propellers set.

[ ] 5. Mixtures rich.

[ ] 6. Carburetor heat off.

[ ] 7. Fuel on.

[ ] 8. Engine gauges normal.

[ ] After the take-off has proceeded to the point where a landing can no longer be made with wheels-down in the event of power failure, the wheels should be retracted. As the wheels come up, the throttle should be brought back to climbing power, 25" MP, and the RPM reduced to 2400. Minimum single engine speed (65 MPH) should be attained as soon as possible. The best rate of climb is obtained at 85 MPH, but to give a high forward speed as well as a good rate of climb, a cruising climb speed of 110 MPH is recommended.

[ ] The gross weight power off stalling speed of the G21a is 62 MPH with full flaps. The stalling speed increases to about 69 MPH with flaps up. All controls are effective at speeds down through the stalling speed, and stalls are gentle and easily controlled.

E. Cruising

[ ] The cruising speed of the G21a is determined by many factors including power setting, altitude, temperature, load; and equipment installed on the airplane. The normal recommended cruising power setting of the Goose is at 75% power. At 9000 feet this gives a True Air Speed of 190 MPH. This power setting is obtained under standard conditions at 2100 RPM. and 23.0" MP. Fuel consumption for both engines is 11.7 gallons per hour, or 23.4 gallons per hour total. The maximum cruising speed of the Goose is 190 MPH. The Pratt & Whitney Wasp Jr engines on the Goose can be cruised at any per-cent of power from 75% down. In general, two standard RPM settings are recommended, 2300 for high performance cruising and 2100 for moderate power settings, low noise levels, lower fuel consumption and reduced engine wear. An intermediate RPM set-ting may be desired for some power settings to obtain maximum smoothness. To avoid undesirable stresses on the propeller and the possibility of detonation in the engine, no Manifold Pressure settings over 25" should be used with an RPM of less than 2300. Use of the mixture control in cruising flight reduces fuel consumption significantly, especially at higher altitudes. 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. The carburetor heaters on the G21a are of high capacity, and are designed to provide enough heat to remove carburetor icing and related induction system phenomena under most conditions. A heat rise of approximately 100°F can be obtained with the application of fuel heat. This creates a power loss of about 20% with very little indication on the Manifold Pressure gauge, which has a maximum drop of about ½ inch MP. The power loss will show up in the performance of the airplane; and should be held to a minimum by applying only that amount of heat required to keep the carburetor or induction system free of ice. The application of carburetor heat enriches the mixture, and frequently may require resetting the mixture control for smooth and economical engine operation.

F. Approach And Landing

[ ] During the approach, the gear can be lowered at speeds under 120 MPH, preferably on the downwind leg. DO NOT LOWER GEAR WHEN MAKING A WATER LANDING! Flaps should be lowered in final approach at an airspeed under 110 MPH, and the airplane trimmed to a gliding speed of 70 MPH. Normally about 12" MP should be maintained to give a reasonable approach angle. RPM should be left at high cruising RPM or approximately 2200. This propeller setting gives ample power for an emergency go-around and will prevent over speeding of the engines if the throttle is advanced sharply.

[ ] The amount of flap used during landings and the speed of the airplane at contact should be varied according to the wind, the landing surface, and other factors. It is always best to contact the ground at the minimum practicable speed consistent with landing conditions.

[ ] Normally, the best technique for short and slow landings is to use full flap and a small amount of power, holding the nose up as long as possible before and after ground contact. In high wind conditions, particularly in strong cross winds, it may be desirable to approach the ground at higher than normal speeds, with half or no flaps.

Landing Check List:

[ ] 1) Mixtures rich..

[ ] 2) Propellers at high cruising R.P.M.

[ ] 3) Carburetor heat off (unless icing conditions exist).

[ ] 4) Fuel on proper tanks.

[ ] 5) Landing gear down (under 120 MPH), check orange indicator light on.

[ ] 6) Flaps full down or as desired (under 110 MPH).

G. Stopping The Engines

[ ] During the landing roll, the flaps should be raised and the heater turned off. After parking, the radios should be turned off, and the engines stopped by pulling the mixture controls aft to idle cut-off. The throttle should be left full aft to avoid engine vibration while stopping.  After the engines stop then the ignition and master switches should be turned off.