Crop-dusting pilots use lazy eights as course reversals. It's an efficient way to execute 180° turns while dusting a field.

The purpose of the lazy eight is to develop the proper coordination of the flight controls across a wide range of airspeeds and attitudes. This involves the pilot developing a feel for the aircraft while it exhibits consistent and constant changes in control forces.

Flight controls are never constant: The lazy eight develops the proper coordination of the flight controls across a wide range of airspeeds and attitudes. Throughout the maneuver, flight controls are never constant.

Course reversals with climbs and descents: S-turns across the road, which is a ground-reference maneuver, are made of opposing 180° turns. The lazy eight adds both a climb and descent to each 180° segment. The first 90° is a climb; the second 90° is a descent.

Select reference points: Prominent reference points must be selected on the natural horizon at 45°, 90°, and 135° from the direction in which the maneuver is started for each 180° turn.

Maneuver entry: Gradual climbing turn: From level flight, a gradual climbing turn is begun in the direction of the 45° reference point, where the maximum pitch-up attitude is reached, as well as a 15° bank angle.

• As airspeed decreases, the rate of turn increases.
• Also, as airspeed decreases, more rudder input will be required to counter left-turning propeller forces.

Avoid rapid roll entry: If the lazy eight is started with too rapid a roll rate, the 45° point may be reached before the maximum pitch-up attitude is reached.

Avoid steep bank entry: If the climbing turn portions of a lazy eight are entered with banks that are too steep, the turn rate will be too fast for the rate of climb. The 180° change of direction will be reached with excessive airspeed.

The 90° point: Beyond the 45° reference point, the pitch-up attitude should begin to decrease slowly toward the horizon until the 90° reference point is reached, where the pitch attitude should be momentarily level with a bank angle of 30°.

• Airspeed should be 5-10 knots above stall speed.

Opposing aileron and rudder inputs: At the 90° point, where airspeed is lowest, it's possible for opposing aileron and rudder pressures to be required to maintain coordinated flight.

• This is because of the increased right rudder pressure required to overcome propeller forces at lower airspeeds.

Descending to the 135° point: On the descending portion of the turn, the bank should slowly roll out as the pitch attitude decreases.

Lowest pitch attitude: The lowest pitch attitude should occur at the 135° reference point.

Arriving at the 180° point: The wings and nose should be level at the original airspeed just as the 180° point is reached.

Change directions: A climbing turn is then started immediately in the opposite direction to complete the second half of the lazy eight.

Procedure

• Select a heading and an external reference
• Establish level flight at or below maneuvering speed (Va) or manufacturer's recommended entry speed Begin a gradual climbing turn is begun in the direction of the 45° reference point.
• At 45° reference point, establish maximum pitch-up attitude and 15° bank angle.
• At 90° reference point, level pitch attitude, 30° bank angle, and airspeed 5-10 knots above stall speed.
• At 135° reference point, lowest pitch attitude.
• At 180° reference point, a return to original airspeed and altitude.

Too much roll — too early: Beginning the turn with too rapid a rate of roll would cause the 45° point to be reached before the maximum pitch-up attitude.

Banks too steep — too much airspeed: If a pilot initiates the climbing turn portions of the lazy eight with banks that are too steep, the maneuver may be performed with turns that are at a rate too fast for the rate of climb. The result would be completing each 180° change of direction with excessive airspeed.

Too much pitch — stall: If a pilot initiates the climbing turn portions of the lazy eight with excessive pitch, the maneuver may be performed with a pitch attitude that is too steep, leading to a stall at the top of the climbing turn.

Common errors when performing lazy eights include:

• Not clearing the area
• Maneuver is not symmetrical across each 180°
• Inadequate or improper selection or use of 45°, 90°, 135° references
• Ineffective planning
• Gain or loss of altitude at each 180° point
• Poor control at the top of each climb segment resulting in the pitch rapidly falling through the horizon
• Airspeed or bank angle standards not met
• Control roughness
• Poor flight control coordination
• Stalling at any point during the maneuver
• Execution of a steep turn instead of a climbing maneuver
• Not scanning for other traffic during the maneuver
• Performing by reference to the flight instrument rather than visual references

Completion Standards

Commercial Pilot & CFI Airmen Certification Standards (ACS)

• Select an altitude that will allow the maneuver to be performed no lower than 1,500 feet AGL.
• Maintain coordinated flight throughout the maneuver.
• Approximately 30° bank at the steepest point.
• Constant change of pitch and roll rate and airspeed.
• Altitude at 180° point: ±100 feet from entry altitude.
• Airspeed at the 180° point: ±10 knots from entry airspeed.
• Heading at the 180° point: ±10 degrees.
• Continue the maneuver through the number of symmetrical loops specified, then resume straight-and-level flight.