Flying Tourbillon

The flying tourbillon distinguishes itself from the classical tourbillon through one precise constructive detail: the cage is anchored on only one side, without the upper bridge closure. The technique was perfected in 1920 by German watchmaker Alfred Helwig, and since then it has remained one of the most copied and most misunderstood solutions in haute horlogerie.

In the traditional tourbillon, the cage is held between two bridges, one lower and one upper: a solid structure, geometrically stable, but one that obscures the view of the mechanism. Removing the upper bridge completely frees the sight line, but introduces a real engineering challenge: the upper pivot of the cage must support alone the stresses that in a balanced system are distributed across two points. The solution passes through tighter tolerances, lighter materials, and often titanium cages or exotic alloys that reduce the rotating mass.

From my bench I have seen how this construction has two immediate effects: on the aesthetic side, the cage appears suspended in the void, an effect that works better on open or skeletonized dials; on the technical side, reducing the mass of the cage lowers the moment of inertia and can favor subtler movements. The Bianchet Rotondo UltraFino reaches 3.85 mm in height also thanks to this choice. Piaget, whom I know well from my years on those ultra-thin calibres in the seventies, used this logic systematically.

The flying tourbillon can be fixed in position, as in the Audemars Piguet Code 11.59 at 6 o'clock, or orbiting: in the Jaeger-LeCoultre Master Grande Tradition calibre 948 it travels the entire dial in 24 hours, becoming itself a time indicator. There is also the inclined variant, as in the David Candaux DC7, where the cage is tilted 30° relative to the dial plane to compensate for gravity effects across multiple wearing positions.

A related but distinct concept is the flying governor, the speed regulator of minute repeaters: similar name, completely different function. It controls the rhythm of the chimes, not the accuracy of the balance wheel. Ulysse Nardin's flying carousel in the Freak also takes up the idea of a structure without an upper bridge, but applies it to an entire segment of the movement that serves as a hand.

Be careful with terminology in catalogues: «flying tourbillon» always indicates the same thing; «orbital tourbillon» adds the rotating motion around the dial, which is a separate additional complication.