Two ILS approaches, same runway, same NAVAIDS

[rframe]

Brushing up for my CFII and wanted to run this by you guys.

If you look at KMSO, there are two ILS approaches for RWY 11:
ILS Y RWY 11
ILS Z RWY 11

These approaches are almost identical, same feeders, arcs, frequencies, step downs, etc.

The only difference is the 1600' difference in decision height and 6.5 miles visibility for minimums and missed approach.

I believe this is entirely related to climb gradients. With the ILS Y accomodating the minimum 200' per nm standard, while ILS Z gives aircraft with better climb performance much better landing minimums.

Is my understanding correct? Is there anything else to this?

 

[SurferLucas]

Brushing up for my CFII and wanted to run this by you guys.

If you look at KMSO, there are two ILS approaches for RWY 11:
ILS Y RWY 11
ILS Z RWY 11

These approaches are almost identical, same feeders, arcs, frequencies, step downs, etc.

The only difference is the 1600' difference in decision height and 6.5 miles visibility for minimums and missed approach.

I believe this is entirely related to climb gradients. With the ILS Y accomodating the minimum 200' per nm standard, while ILS Z gives aircraft with better climb performance much better landing minimums.

Is my understanding correct? Is there anything else to this?

Hit the nail on the head there. For the ILS Z Runway 11 at MSO, we have a special Single Engine Turn Procedure in place in the event we have an engine failure on the approach. We have a few of these types of approaches in our system. Wenatchee (EAT) has the same, RNO has the ILS 16R and the Silver ILS16R, etc.

 

[DE727UPS]

I believe that's all there is to it. MA climb performance.