  The present paper attempts to show an alternative approach with regards to
rational Pythagorean-hodograph (PH) curves and especially more natural approach
for rational PH helices (i.e. rational helices). It exploits geometric features
of rational helices to obtain a simpler construction of these curves and apply
this to related subjects. One of these applications is Geometric C1 Hermite
interpolation (i.e. interpolation of end points with associated unit tangents)
by rational helices. Furthermore, we investigate the existence of rational
rotation minimizing frames (RRMFs) on rational helices. A rational
approximation procedure to rotation minimizing frames (RMFs) is suggested.
Subsequently, we deploy the approximate frame for modeling a rational sweep
surface. The resulting algorithms are illustrated by several examples.
