Look particularly for the clean initial stall. If the aircraft lifts and rolls or flicks into the autorotation this indicates clearly that it must have been flying at above stalling speed, and you must then give the figure a Perception Zero mark. A smooth and accurate transition from the spin directly into the down line without any aileron assistance is also crucially important.
A 'wrong-direction' (90°, 180° or 270° out) exit on the "A" or "B" axis of course hard zero’s the figure, and on the "A" axis this will be followed by further zeroes until the mistaken direction is corrected Note in the figure shown here that the Aresti symbol shows a negative down-line because without the spin the basic manoeuvre would require a 'push' entry from horizontal.
In a well executed Spin you should see
A clearly visible stall in positive or negative horizontal flight, on the correct heading and without any roll or yaw. The nose should drop without the CGT rising, while at the same moment yaw and roll should begin and lead immediately to autorotation. The rotation should stop and coincidentally the nose should drop to the vertical (ZLA) with the aeroplane on the right heading. There must be no perceptible aileron roll to establish the correct final down-line axis. Note also the curved trajectory of the down-line. The aircraft should draw a vertical line (ZLA) and then execute a constant radius pull or push through to horizontal flight on the right heading. This clearly shows the decay in forward energy of the aeroplane, from stall-speed to a virtual stop before the final pull.
- Is the CGT maintained up to the point of dropping into the spin? Height gain or loss is wrong.
- Entry heading, and roll & yaw prior to the stall: 1 point/5°
- The spin entry - does it stall > yaw > drop into the spin properly, or is it flicked or forced? (PZ)
- As the spin stops, is it on heading without aileron 'assistance' - 1 point/5° if not.
- Verticality of the down-line: 1 point/5° for axis, roll or yaw accuracy.
- Rolls on the down-line must follow the spin after a short pause, ie. they are not 'centred'.
- Exit line (or it could be a 3/4 loop, 45° up or another vertical etc.) - CGT or ZLA criterion as usual.