MI 26 - The Arch with Stops (Experienced)
Compulsory figure from the series Multi-line individual figures.
Reference diagram
Official document: ISK Compulsories Book v3.0, p. 88
Official description
Judges will particularly consider
- Speed control
- Arch
- Stops
Explanation
- IN is at <30 of the wind window on the ground.
- The kite flies up before making a clearly defined stop at ˄50<, then continuing in a semi-circle making further clearly defined stops at ˄80 and again at ˄50>
- After the second stop the kite continues into vertical downward flight
- Finally the kite makes a controlled landing at >30 of the wind window on the ground. Pilot calls OUT.
Our reading
What follows is our reading of those documents, not an official document: the diagram and the description above are what counts.
Animation
Sequence
Doubts & discrepancies
Uncertain readings of the diagram or the official text, and disagreements between sources, to be validated. The animation follows the reading we chose, which is not an official interpretation.
- écartHow many stops? The diagram marks only two (“Stop #1” at ^50<, “Stop #2” at ^50>), and point 3 of the text speaks of the “second stop” before the descent. But point 2 announces three (^50<, ^80, ^50>). The animation adds the stop at ^80, in the middle of the arch.
Common to the whole family of figures
- douteOverall speed: we chose a constant speed of 15 units per second (about 4.4 m/s with 37 m lines), without any flight measurement. The ISK requires a constant speed (§II.V) without giving a value.
- douteKite size: our assumption is a wing 2.30 m wide, i.e. 8 grid units (1 unit ≈ 0.29 m with 37 m lines), with the proportions of the Hadzicki wing drawn in kite-physics; the dual-line wing has the same span. For the reference competition, we only found the scale of the grid (ISK §II.C: about 0.3 m for 38 m), not a kite size. At this size, the wings of a team overlap at times (MT 01, 02, 06 and 09). Lead: a smaller kite.
- douteWe added a brief stop (0.25 s) before and after each rotation on the spot, and at each corner where the wing goes from one translation to another with a different leading-edge orientation. It does not appear in the list of steps, and the rules do not ask for it: they only mention the stops marked on the diagram or cited in the text.
Keep going
In the series Multi-line individual figures
- MI 23 - Slide and Square (Intermediate)
- MI 24 - Basic Elevator (Novice)
- MI 25 - The Arch (Intermediate)
- MI 26 - The Arch with Stops (Experienced) — you are here
- MI 27 - Up, Down, Up (Intermediate)
- MI 28 - Square (Intermediate)
- MI 29 - Quadrato (Intermediate)
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