D-EEHT


Section III

Operating Procedures

Starting the engine

Before priming, set the parking break by depressing the tops of both rudder pedals, and pulling out on the parking brake control knob. It is good practice to have all radios and lights off, both to limit battery drain during the start and to protect avionics from voltage surges.

Note
Normally, one to three strokes of the priming pump is sufficient for quick starting. In temperatures below 40°F, however, four to six strokes may be necessary. During extremly cold days, starting will be aided by pulling the propeller through four or five revlutions by hand. Switches must be OFF when pulling the propeller. Preheating the engine or oil before starting in sub-zero temperatures will speed the start and conserve the battery charge.

With the parking break set, place the mixture in the full rich position; turn master switch and alternator switch ON; clear propeller area; set ignition switch to both; and engage the starter. If the engine fails to start on the first attempt, a second attempt should be made without priming. If the day is hot and the second attempt fails, it is possible the engine is over-primed. Pull the mixture control to full lean, throttle 1/4 open, and turn the engine with the starter. When the engine starts, push the mixture control to full rich. If the day is cold, it is more likely the engine is under-primed. In this event, a few extra strokes of the primer should provide a prompt start.

Check the oil pressure as the engine starts. If no oil pressure is indicated within 30 seconds (60 seconds on a very cold day), stop the engine and determine the source of trouble. Oil pressure should indicate approximately 25 psi with the engine at idle.

Warm-Up and Ground Check

Engine warm-up should be at 800 to 1200 RPM. The magneto check is run at 1800 RPM using the BOTH-RIGHT-BOTH-LEFT-BOTH sequence. Maximum RPM drop per magneto should not exeed 175 RPM, or 50 RPM differential between magnetos. The carburetor heat should be checked for operation at this time, then returned to the full OFF position. The engine is ready for take-off when it will take full throttle without hesitating or faltering.

Take-Off

Before beginning the take-off roll, align the airplane with runway. Aligning the nose wheel with the take-off direction will allow minimum brake usage during the initial ground roll. When full power is applied for take-off, directional control is maintained with light toe pressure on the brakes. At speeds above 15 - 20 MPH, the rudder becomes fully effective and break steering is NOT necessary. Continued use of brake steering will only prolong the take-off roll.

Accelerate to 55 MPH before applying a light back pressure on the control wheel to lift off. Raising the nose wheel too soon or to an excessive angle may increase take-off ground distance. When airborne, accelerate to the desired climb speed.

Soft field Take-Off

After alignment in the take-off direction and with the elevator held in the full up position, apply take-off power smoothly. As the airplane accelerates and the elevator becomes effective, the nose load will lighten reducing nose wheel drag. As the nose raises, the elevator should be eased forward so the nose wheel is held just clear of the ground. After lift-off, accelerate to the best angle of climb speed (78 MPH at sea level) or best rate of climb (91 MPH at sea level) depending on obstacles.

Note:
Avoid prolonged engine run-up in loose gravel, since the propeller will tend to pick up stones and debris causing blade damage.

Short field take-off

After alinement in the take-off direction, advance the throttle without hesitation, and begin the take-off roll with the elevator neutral. Use light smooth brake pressures to maintain low speed directional control. At 60 MPH apply elevator back pressure for rotation, then climb at 73 MPH while in ground effect below 50 ft. If terrain or further obstacles are to be cleared after take-off and above the 50 foot obstacle, accelerate to the best angle of climb speed (78 MPH at sea level). When obstacles are cleared, accelerate to the dsired climb speed.

Note
Speeds given are for gross weight, sea level conditions.

Climb

A normal climb speed of 100 MPH is recommended once over ground obstacles. This offers good visibility, excellent over-the-ground speed and rate of climb. The best rate of climb speed varies from 91 MPH at sea level to 85 MPH at 10,000 ft. The best angle of climb speed varies from 78 MPH at sea level to 81 MPH at 10,000 ft. Refer to Section V performance charts for additional information.

Note
The mixture should be full rich during take-off and climb at altitudes below 5000 ft. MSL. However, during take-off or climb from high-altitude airports, the engine should be leaned to achieve best power (maximum RPM).

Cruise

The maximum recommended cruise power setting is 75% of the rate horsepower. True airspeeds, wich are determined by the particular altitude and power setting chosen, can be obtained from the tables in Section V.

Fuel consumption can be reduced significantly, especially at high altitudes, by leaning the mixture in cruising flight. For optimum fuel consumption in cruise at 75% power or less, lean the mixture as follows:

The Cruise Performance fuel consumption given in Section V is based upon this leaning technique.

Note
If engine runs rough during cruise with carburator heat on, it may be due to an over-rich condition. To correct for engine roughness in such a situation, lean to smooth engine operation.

Stalls

The AA-5´s stall characteristics are conventional in all configurations. Elevator buffeting occurs approximately 3 MPH above the stall and becomes more pronounced as the stall occurs. An audible stall warning horn begins to blow steadily 5 to 10 MPH above the actual stall speed.

Note
Rudder is the primary control for yaw and roll through the stall. In addition, the aileron is effective for roll control. Both controls should be used as necessary to control roll and yaw through the stall.

For specific stall speeds at maximum weight with flaps up and down, refer to the Stall Speed Table in Section V.

Normal Approach and Landing

Trim the airplane to an approach speed between 75 and 80 MPH, depending on weight and wind conditions. Normal approach speed is 75 MPH. Maximum flap speed is 120 MPH. Any flap setting may be used for landings.

As a general rule, it is good practice to contact the ground at a minimum safe speed consistent with existing conditions. After touchdown, hold the nose wheel off as long as possible on roll-out. Lower the nose gently and apply brakes as needed. Retract the flaps after touchdown to minimize the possibility of skidding when braking.

In gusty or crosswind conditions, many pilots prefer to increase their airspeed slightly above the normal approach speed; this decision, however, can only be made by the pilot in light of his own experience and training.

Note
A pilot-induced maneuver may be encountered during landing by contacting the nose wheel first with exessive touchdown speed. The porpoise could be accentuated by a wavy or rolling runway surface. Should a porpoise occur, use the following technique to recover:

A power-off tail-low touchdown attitude is the best assurance of a porpoise-free landing, and excessive touchdown speed is not required with direct crosswind up to 13 MPH.

Short field landing

When making a landing where obstacleclearance or ground roll is a factor, the AA-5 should be trimmed to an approach speed of 70 MPH with flaps fully extended. Touchdown should be made on the main gear at the slowest safe airspeed. Best braking can be obtained by applying light pressure immediately after touchdown and continiously increasing brake pressure just enough so the wheels do not skid.

Soft field landing

For soft fields, the AA-5 should be trimmed to an approach speed of 70 MPH with flaps extended. Use power as necessary to control glide path consistent with existing conditions. Touchdown in a rough or soft filed should be in a nose-high pitch attitude at the slowest safe airspeed. The nose wheel should be held off the surface as long as possible, and braking should be the minimum required for directional control and safety. (Maximum braking on soft surfaces may lead to excessive gear loads.).

Balked landings (Go-arounds)

Should a landing be balked, apply full power immediately; carburetor heat OFF; establish a positive rate of climb; retract the flaps and trim for normal climb.

Slips to landings

Slips are very effective in the AA-5. Rapid descents with high sink rates can be obtained through a properly executed slip. It is recommended, however, that slips be practiced at altitude until the pilot is familiar with the AA-5. The recommended slip speeds are 75 to 85 MPH, depending on load, pilot proficiency, and local conditions. Pilots should make themselves familiar with the airplane at a variety of slip speeds.

Ground handling and tie-down

The AA-5 is easily on the ground by hand with the aid of a tow bar attached to the nose wheel fork. Tie-down rings are provided under each wing tip and under the tail. Proper tie-down is the best insurance against damage to the airplane by gusty or strong winds. Installaton of the control wheel lock helps avoid damage to the movables surfaces under such conditions.

Care should be taken when using the parking breaks for an extended period of time during which an air temperature rise could cause the hydralic fluid to expand, which in turncould damage the brake system and/or cause difficulty in releasing the parking brake. For prolonged parking, tie-down and wheel chocks are recommended.

Additional engine operating information

Refer to the "Operating Instructions" section of the "Lycoming Engine Operator´s Manual" for additional information on fuel mixture leaning procedures, the use of the carburetor heat and general good engines operating procedures to assure maximum engine performance.