Aerobatic Manoeuvres

This is an extract of the schedule specifically written for the F3A Precision Aerobatics Standard routine. Manouevres may be practiced individually, in small sections or as a complete continuous schedule as required at competition level. Generally points are deducted for straying off-line (insufficient wind allowance), poorly formed manouevres and for each 15º off from the vertical entering or exiting a maneuvre. The whole routine is performed within the bounds of an imaginary "box" determined by outlying flags set 60º either side of the pilot on a line 150 metres directly in front of his position which in turn is set some 7-10 metres in front of the judges. A caller stands directly behind the pilot reading out the list of manouevres in turn to the pilot and assisting him to determine where the centre line is and the point at which a particular manouevre should be commenced or exited in order to present a symmetrical display from the judges viewpoint within the bounds of the boxed area.

Note: Where stated a vertical flight path refers to the path of the aircraft, and NOT the attitude of the aircraft which may have to "lean in" or "lean out" as correction for the wind in order to achieve an ideal vertical flight path.

Take Off Sequence

The helper should position the model on the runway. Take off into wind and climb out in a straight line at about 30º. Turn 90º away from the flight line and then perform a 270º turn at your preferred baseline height. This is now setting your depth from the flight line for your whole schedule. Continue past the centre line and perform a turn around maneuvre of your choice to set up for your first centre manouevres.

Two Inside Loops

All loops must be performed on the centre line, be perfectly round and have the same entry and exit height. Starting from level flight with the wings perfectly level open the throttle and as you pass the centre marker ease back on the elevator. As the model climbs watch the shape of the loop and adjust both throttle and and elevator as required to keep the loop round. Do not snap the throttle closed at the top of the loop or the model will flop. Ease the throttle back until the model is well over the top before closing it. Finish the loop in level flight with a normal throttle opening and prepare for the next manouevers.

Half Reverse Cuban Eight

From straight and level flight perform a 1/8 loop to a 45º upward flight path. Half way along complete a half roll to inverted, possibly using some down elevator and complete a 5/8 inside loop to level flight. A progressive reduction in the throttle setting will result in a smoother and more accurate manoeuvre.

Two Consecutive Rolls

When exiting the Half reverse Cuban Eight be prepared to commence the 2 consecutive rolls. Start this manoeuvre early enough so that the first roll is completed at the centre line. The 2 rolls may require coordination of rudder and elevator in the same way as flying a slow roll but in this case the roll rate is much quicker.

Stall Turn

From a noticeable straight and level flight, perform a quarter loop to a vertical flight path with power on making allowances for the wind, and at a reasonable height close the throttle. When the aircraft has almost stopped apply sufficient rudder to perform the turn at the top of the stall.The allowable radius at the top of the stall is half a wingspan. A turn of more than one and a half wingspans could be seen as a wingover and severely marked down.

Square Loop

With the wings perfectly level fly past the centre line and pull through a quarter loop to vertical flight. Pull through another quarter loop to fly level inverted at the upper flight level. Throttle back to slow the model down then at the correct point after the centre line pull through another quarter loop to vertical downward flight. At the correct height pull through another quarter loop to level flight at the base line height. Allowance must be made for the wind and all quarter loops must have the same radius.

Immelman Turn

This is a Half Loop with a Half Roll at the top.The Half Roll must be executed immediately after the Half Loop, ie there should be no straight and level flight between the two parts of the manoeuvre as this is one manoeuvre. Ideally the Half Loop should be a perfect half circle and the roll rate must be constant. The manoeuvre as a whole should start and end with level flight.

Two Outside Loops

Having just completed an Immelman and with the wings level at the higher flight line ease the throttle back as you push the elevator forward. As the model continues round, and just before you reach the bottom of the loop start to increase the throttle. Keep the wings level and check the shape of the loop as you go along, possibly stretching the bottom to keep it round depending upon the wind strength. The second Outside Loop should be an exact copy of the first, on centre and remembering to exit wings level throttle back in preparation for the next manoeuvre.

Half Square Loop, Half Roll Down

From straight and level flight at a low throttle setting push the elevator forward and perform a Quarter Outside Loop to a downwards flight path, Half Roll when halfway down then pull the elevator to perform a Quarter Inside Loop to finish in Level Flight. If you start this manoeuvre with insufficient height better to recover through a Split-S and lose points than lose your model. A larger Immelman and larger outside loops will get your model high enough to complete this manoeuvre safely.

Cuban Eight

Fly past the centre line and perform a 5/8 loop to 45º downline, after a short distance half roll and continue down at 45º perform a 3/4 loop to a 45º downline, after a short distance half roll and continue at 45º the a 1/8 loop to level flight. The manoeuvre should be symmetrical with the cross-over on the centre line.

Top Hat with 1/4 Rolls Up and Down

From level flight perform a quarter loop to a vertical flightpath, making a quarter roll half way up the vertical line and continue to the top of the box.Now perform a quarter loop so that the model is inverted. fly straight and level inverted for a short distance before pulling a quarter loop into a vertical downward flight path. Halfway down make a quarter roll followed by a quarter loop puling out upright with the wings level flying back towards the centre-line along the baseline. Good use of correction during the Top Hat will ensure a good position for the next manoeuvre.

Straight Inverted Flight

With the wings level and at a reasonable distance before the centre marker half roll to inverted. When you are at an equivalent distance past the centre-line half roll again to level flight.

Half Cuban Eight

With the wings level perform a 5/8 inside loop to a 45 degree down-line. Halfway down complete a half roll and pull to complete a 1/8 loop to resume level flight.

Double Immelman

With the wings level, fly along the baseline past the centre marker a short distance then pull the model into a Half Loop with a Half Roll at the top to upright and fly straight and level to the same distance past the centre line. Ease the throttle back and push into a 1/2 outside loop to the baseline. As you approach the baseline gradually increase the throttle. At the baseline immediately Half Roll to upright and fly past the centre line to complete the manoeuvre.

Humpty Bump with Options

From level flight perform a quarter loop to a vertical flight path, making a half roll half way up, push a half outside loop to a vertical downline then a quarter loop to level flight. Optionally you can make a quarter roll half way up the vertical but you will then have to perform a quarter roll on the way down ensuring that you quarter roll correctly to face the right way.

Slow Roll

The Slow Roll requires tremendous coordination between aileron, rudder and elevator if you want to do it properly. start the manoeuvre from straight and level flight and at a reasonable distance from the centre marker start a slow roll. If you roll clockwise progressively apply left rudder to keep the nose up whilst inverted. Still rolling, progressively reduce down elevator whilst applying right rudder until at knife edge then reduce right rudder until level flight is achieved. The aircraft should be inverted as it passes the centre marker.

Half Square Loop, Half Roll Up

Unless you have unlimited power you will need full throttle as soon as the slow roll is complete as the next manouevre after this one is a spin which requires maximum height....

Following the slow roll, pull into a quarter loop to vertical flight. Half way up the vertical perform a half roll. Continue with the vertical flight then push to complete a quarter outside loop to horizontal flight and throttle back ready for the spin.

Two and a Half Turn Spin Half Roll on Exit

Approach the centre of the box slowly. As the speed drops apply more and more up elevator to keep the aircraft on a level flight-path. As the aircraft stalls one wing will drop so apply rudder in that direction as this is the direction that the spin will take. The spin consists of full elevator and full rudder - NO aileron input! At approximately two turns centre the rudder and push a little down elevator to stop the spin (which make take 1/2 turn) to complete the 2 1/2 turn spin. Now point the aircraft vertically downwards then push the elevator to perform a quarter outside loop into wind. Fly level inverted for a short distance then half roll to level flight.

Landing Sequence

Following the exit from the spin manouevre make a 180º turn and begin the downwind leg, making a further 180º turn into the final approach maintaining a straight gradually descending path to the touchdown point. The model should not climb during any part of the landing procedure, but should gradually descend with the wings level apart from during the two 180º turns.

The above extract is from the Great Britain R/CAerobatic Association leaflet. For more information on the GBRCAA including how to join, click the link on the following page organisations.