Basic Acrobatics
Basic of Acro Performance
This section is a tool to assist you with flights during the Precision Landings/Aerobatics phase. It will cover basic procedures and information in regards to unusual flying attitudes and precision flying. You may want to refer to this documents while completing this phase of training. The following is a list of areas that will be discussed within this document:
Aerobatic Checklist
1. Aerobatic Cruise: Airspeed should be approximately 300-350 kts.
2. Altitude: Floor set at 5000 feet Baro for all maneuvers.
3. Clearing Turns: This will allow you to clear the area in which you are operating. A clearing turn shall be executed prior to the performance of any aerobatic maneuver. Utilize a minimum of 180 degrees of heading change. Two 90 degree turns in opposite directions will suffice. The direction of the last clearing turn shall be in the direction in which the maneuver will be performed. Continue the turn until you have the desired airspeed and sufficient ground references to maintain orientation during the maneuver.
Precision landings
A precision landing is simply landing executed with a high degree of precision. Your landings should occur consistently on or near the intended point of landing.
By this point in your training, you should be developing the exacting landing techniques and experience which will enable you to execute precision landings consistently.
Fly a normal approach to landing looking for the runway threshold (piano keys). Concentrate on air work and pattern consistency. Pay particular attention to:
a. Downwind/Abeam Position.
Maintain pattern altitude, proper airspeed on downwind . In no case shall any aircraft be established downwind in excess of 180 kts. Always commence the approach turn abeam the intended point of landing.
b. 90 Degree Position.
Fly a pattern that consistently puts the aircraft over the same point on the ground, at 400’ AGL, when you are at the 90 degree position.
c. Arrival on Straightway.
Fly a pattern that consistently puts you on the straightway at the same point over the ground. Avoid angling in or overshooting. You should arrive at this point with final approach airspeed, 1200 feet of straightway and 100-150’ AGL. The vertical velocity should be approximately 700 down.
d. Directional Alignment on Final.
Maintain your aircraft on extended centerline all the way to touchdown. Use the runway centerline as an alignment aid. Scan up and down the runway and avoid fixation.
e. Attitude on Final.
Maintain final approach attitude as you approach the intended point of landing. Remember to control rate of descent with power while controlling the airspeed with nose attitude.
f. Transition to Landing.
Approaching the point of intended landing, start a gradual transition to the landing attitude. A normal touchdown on the main gear with the aircraft in approximately the same attitude should be made on each landing.
g. Strive for consistency in each pattern.
Without consistency in the pattern, there is no basis from which to make corrections. Diving for the deck when high, and holding off when low are not the correct methods of compensating for errors which occur earlier in the approach. It must be remembered, however, that proper airspeed, altitude, and turn must be used in the approach pattern in order to execute a precision approach to a precision landing.
Unusual attitudes
Recovery from unusual attitudes shall be accomplished as smoothly and expeditiously as possible. To recover from an unusual attitude, the pilot must first determine aircraft attitude by use of visual references. To determine the attitude of the aircraft and
thus the proper recovery technique, the pilot should immediately check the position of the nose. While maintaining this
attitude, he should check the position of the wings. If inverted, roll in the shortest direction to the upright position and then complete the recovery as follows:
1. Nose Low
a. POWER - IDLE TO MINIMIZE ALTITUDE LOSS AND AIRSPEED BUILDUP.
b. WINGS - Level the wings and center the ball.
c. PULLOUT - Commence a smooth pullout. DO NOT exceed 14 units AOA or aircraft G limits
2. Nose High
a. Using aileron and rudder, roll towards, but not necessarily to 90 degrees angle of bank.
b. Using bottom rudder, fly the nose of the aircraft through the horizon.
c. As the nose passes through the horizon, roll wings level.
d. Once the wings are level, raise the nose as in a nose low unusual attitude.
Loop
The loop is a 360-degree turn in the vertical plane. During the loop the aircraft is rotated at a constant rate of pitch about its lateral axis. In this maneuver, the elevator is the principal control surface utilized. The nose pitch rate should be constant, but the aft stick force required to obtain this will vary with airspeed and G loading. Directional control is maintained using rudder input as the airspeed varies, thereby maintaining balanced flight.
Transition to aerobatic cruise and complete the aerobatic checklist. Commence a clearing turn. During the last 90 degrees of turn, lower the nose slightly and accelerate. Roll out of the clearing turn on or parallel to a section line with 250-300 kts.
1. Note the entry altitude. Check and report the entry altitude
2. Commence pull-up to obtain 5 G's in 2-3 seconds. Do not use aileron.
3. Keep the wings level.
4. Tilt head back to find the opposite horizon. recheck wings level.
5. Keep the nose moving at a constant rate. Airspeed will reach its slowest point at the top of the loop.
6. Allow the nose to fall along the section line.
7. Smoothly increase aft. stick pressure as necessary to maintain a constant pitch rate. Speed is regained. The recovery will again require approximately 5 G’s.
8. Quickly scan the altimeter during recovery in order to return to straight and level flight at approximately the same altitude, airspeed, and heading from which the maneuver was initiated.
Inverted flight
Inverted flight is a natural part of many aerobatic maneuvers you will perform during this stage (loops, barrel rolls, etc.).
1. Establish the aircraft at 250-300 kts, clean configuration. Perform the aerobatic checklist. Perform clearing turn and roll out on a suitable section line.
2. Raise the nose and roll the aircraft in either direction using rudder and aileron to the inverted position. Once inverted, neutralize aileron and rudder and utilize slight forward stick pressure to maintain altitude. Immediately note the clock sweep second.
3. Prior to 15 seconds inverted, utilize coordinated aileron and rudder to roll the aircraft back to the upright flight attitude.
Aileron roll
The aileron roll is a 360 degree roll about the longitudinal axis of the aircraft. Plan your clearing turn so as to roll out on a good section line or with the nose aimed at a prominent reference point. When performing the maneuver make your control inputs smooth, brisk, and positive. DO NOT MIX UP YOUR STICK CONTROLS!!!
1. Transition to aerobatic cruise and complete the aerobatic checklist. Commence a clearing turn and roll out with the required ground references.
2. Commence the maneuver by smoothly raising the nose to place the exhaust stacks on the horizon while keeping the wings level. Stop the nose movement by relaxing back stick pressure.
3. Roll briskly in either direction by applying lateral stick deflection and rudder in the same direction (rudder will counter the adverse yaw). The amount of stick deflection will determine your rate of roll. If the rate of roll is too slow the nose will fall below the horizon and a rolling pullout will result.
4. As you approach wings level attitude, ease out aileron and rudder pressure to recover with the wings level and the nose attitude reset for level flight.
Barrel roll
The barrel roll is a maneuver in which the aircraft is rolled 360 degrees about an imaginary point which bears 45 degrees off the nose of the aircraft. This maneuver is designed to develop your ability to maintain orientation.
1. Transition to aerobatic cruise and complete the aerobatic checklist. Commence a clearing turn and roll out on or parallel to a section line. Pick a prominent reference point on the horizon 90 degrees to either side of the nose, in the direction you intend to perform the maneuver.
2. Note entry altitude.
3. Smoothly raise the nose while keeping the wings level. Roll and pull so that the nose travels around in an arcing path toward the selected 90 degree checkpoint. After 45 degrees of turn, the AOB should be 90 degrees and the nose will be at its highest point during the maneuver (approximately 55-60 degrees above the horizon).
4. Continue rolling the aircraft at a constant rate until in a wings level, inverted attitude, heading directly at the 90 degree reference point on the horizon. Your nose should be slightly above the horizon and the airspeed between 200-300 kts.
5. Fly the aircraft through the inverted position and continue rolling at a constant rate, completing the maneuver on the original heading and altitude at aerobatic cruise airspeed. Maintain a positive G load throughout the maneuver. If you exceed the G limit, it’ll most likely happen here. If performed properly, 2.0 G’s should not be exceeded at any time.
6. The nose should appear to make an arcing path about the imaginary point on the horizon 45 degrees from your original heading. The last half of the arc will, therefore, be the same distance below the horizon that the first half is above the horizon. Remember, as the airspeed decreases toward the top of the maneuver, it will be necessary to increase the deflection of the ailerons, rudder, and elevator to maintain a constant rate of pitch and roll. Conversely, as the airspeed increases toward the bottom of the maneuver, it will be necessary to decrease the deflection of the ailerons, rudder, and elevator to maintain a constant rate of pitch and roll. Notice that this roll is started as a climbing turn, which then becomes a continuous roll at a constant rate.
7. Maintain orientation throughout the maneuver by concentrating on your reference points. Maintain a constant rate of roll and nose movement. Inscribing a small arc above the horizon in the first half of the maneuver and a larger arc below the horizon in the last half will result in too great an airspeed at the completion of the maneuver or unnecessarily high G forces to recover on airspeed.
8. During the rollout to the original heading, adjusting the back stick pressure will enable you to recover on altitude and at aerobatic cruise airspeed.
One-half Cuban Eight
The One-half Cuban Eight combines the first 210 degrees of a loop, a half roll to the upright position, and a 45 degree diving pullout to level flight on the original altitude and reciprocal heading. This maneuver offers a quick means of reversing the direction of flight while preserving the original altitude and airspeed. Remember to select a long, well defined section line which extends behind as well as in front of you.
1. Transition to aerobatic cruise and complete the aerobatic checklist. Commence a clearing turn. During the last 90 degrees of turn, lower the nose slightly and accelerate to 250-350 kts. Roll out of the clearing turn on or parallel to a section line with 250-350 kts.
2. Note the entry altitude.
3. Commence a loop.
4. As the nose approaches a point 30 degrees below the opposite horizon, slow the nose movement by releasing back stick pressure and commence a roll in either direction, using aileron and rudder. During the roll, it will take slight forward stick pressure as the aircraft passes wings vertical to hold the heading and allow the nose to continue pitching downward to a position 45 degrees below the horizon.
5. Commence a smooth pullout to straight and level balanced flight prior to the original entry altitude. Recover on the original altitude and reciprocal heading.
Split-S
The Split-s maneuver combines the first half of an aileron roll with the last half of a loop. The Split-S provides a means of rapidly converting the potential energy of altitude into airspeed while reversing the direction of flight. Once the pull is commenced from the inverted position, airspeed builds rapidly and altitude is quickly lost. If performed correctly, the altitude loss should be approximately 2500’. Remember to select a long, well defined section line which extends behind as well as in front of you.
1. Transition to aerobatic cruise and complete the aerobatic checklist. Commence a clearing turn. During the last 90 degrees of turn, reduce power to idle and apply back stick pressure as necessary to maintain altitude. Roll out and continue to maintain altitude, slowing to 230-280 kts.
2. Raise the nose above the horizon, relax the back stick pressure and roll in either direction using aileron and rudder to the inverted position. Once inverted, neutralize the ailerons and apply slight forward stick pressure to momentarily maintain straight and level flight.
3. Quickly verify that the wings are level by referencing the horizon and correct as necessary.
4. Apply back stick pressure, pulling the nose through the horizon and flying the aircraft along the section line as in the last half of the loop. You’ll probably pull about 5.5 G’s.
5. Reset aerobatic cruise power.
Immelmann (also known as a “Hail Mary”)
The Immelmann combines the first half of a loop followed by a half-roll to the wings level attitude. It achieves a 180 degree change of direction of flight and a gain in altitude of approximately 1000 feet. This maneuver offers a quick means of reversing the direction of flight while trading excess airspeed for increased altitude. Remember to select a long, well defined section line which extends behind you as well as in front of you.
1. Transition to aerobatic cruise and complete the aerobatic checklist. Commence a clearing turn. During the last 90 degrees of turn, lower the nose slightly and accelerate to 250-350 kts. Roll out of the clearing turn on or parallel to a section line with 250-350 kts.
2. Note entry altitude, commence a loop. As the nose approaches a point 20 degrees above the opposite horizon, slow the rate of nose movement by neutralizing back stick pressure.
3. Commence a roll in either direction to the upright position using aileron and rudder. Anticipate the need for slight forward stick pressure as the aircraft passes 90 degrees of roll. Rudder input should initially be opposite the direction of roll, followed by a reversal to the same direction as the aircraft passes the wings vertical position.
4. The maneuver is complete when the aircraft is once again in the level flight attitude on the reciprocal heading. You may have reduced airspeed which in turn will show the nose being a little high.