alphacentauri
any issues in the mode change from RNAV to ILS. For example is the mode change prior to LOC intercept or do you bring them on the final approach track under RNAV and then do the mode change.
The mode change methods may vary from one type of equipment to the next.
Many avionics have an automatic "nav-to-nav" transfer capability, but that functionality is not strictly specified by
AC 90-108, paragraph 10.
10. SPECIFIC REQUIREMENTS TO FLY RNAV SEGMENTS PUBLISHED ON ILS PROCEDURES. In order to fly RNAV transitions to an ILS final approach or RNAV missed approach segments of an ILS procedure, pilots must comply with the operating requirements of this AC. RNAV systems used for this type of operation must allow for a means to become established on the ILS final approach course with minimal overshoot or undershoot.
In the case of the JAC ILS, the WOMRU waypoint is on the centerline of the LOC and the course change at WOMRU is less than 20-degrees, so there should be no problem with intercepting the LOC, even without automatic nav-to-nav transfer -- or even without a Flight Director <gasp!>.
Obviously, the Final Segment is flown by reference to the LOC and GS.
Please remain mindful that this procedure can be flown by any IFR-rated pilot. The airplane doesn't have to be built by Boeing or Airbus... it doesn't even have to be a transport category aircraft. A light single engine airplane equipped with an IFR GPS and an ILS receiver would be eligible.
Hope this clarifies a bit -- it's not necessary to "over-think" and make the procedure more complex than it actually is.