Gentlemen
The mentioned turn is not to perform a back course procedure for rwy 27..it is to reverse course an commence an ILS approach for rwy 09
We normally arrive trough a point called INDUR which according to the jeppesen STAR must be crossed at or above FL140 and it used to be at or above FL160..therefore a direct ILS approach on to rwy 09 was not always possible ( acft heavy...need for eng&wing anti ice in winter...etc )
so you proceed to ZVR vordme holding an loose altitude in the hold and when it is jugged feasible to commence your approach, you leave ZVR holding on radial 140 deg to 4.3 DME turn left back to the vor then leave the vor on radial 249 deg reducing speed to 190 kts max to 9.3 DME then turn right to intercept the ILS FRONT course to ryw 09
regards
bf