rotates about an axis the delta blade systems extend outward radially away from the hub in a plane perpendicular to the hub 39 s axis of rotation the invention can incorporate any number of delta blade systems preferably two or three each delta blade system is spaced equidistant from the adjacent delta blade systems each delta blade system is comprised of a leading blade a trailing blade a spherical joint and a torsion bar system the tip of the leading blade is connected to the tip of the trailing blade via the spherical joint the spherical joint is connected to the hub via a torsion bar system the roots of the leading blade and the trailing blade are connected to the hub throughout this specification and claims the terms u201c root u201d and u201c proximal end u201d are used interchangeably the root of each blade is connected to the hub by any means now known or hereinafter discovered for example and not by way of limitation in one embodiment the root is connected to the hub with a ball joint or universal joint fig4 and 5 show two other alternative embodiments fig4 shows a torsion bar 46 within either the leading blade or the trailing blade connected to the hub via a crown gear 40 a bevel gear 42 and bevel gear support 44 in fig5 the torsion bar 50 is connected to the hub 56 with a gear 52 and bearing 54 one skilled in the art will appreciate that the roots of the blades can be connected to the hub in many different configurations the torsion bar system comprises a minimum of one torsion bar preferably a plurality of torsion bars fig1 depicts the invention with.