Jackson Hole ILS

[flyboy102]

I'm planning on flying into Jackson Hole (KJAC), and after looking over the approaches I noticed something odd. ILS or LOC RWY 19 has two plates, Y and Z. On Y the minimums are higher, and there's a note saying fly visual at DH from 1.8 miles out...kind of like a non precision MDA. My question is, why do these two approaches exist? And when might you ever choose to fly Y instead of Z with lower minimums?

 

[gismo]

I'm planning on flying into Jackson Hole (KJAC), and after looking over the approaches I noticed something odd. ILS or LOC RWY 19 has two plates, Y and Z. On Y the minimums are higher, and there's a note saying fly visual at DH from 1.8 miles out...kind of like a non precision MDA. My question is, why do these two approaches exist? And when might you ever choose to fly Y instead of Z with lower minimums?

Check the missed approach instructions on Z. The lower DH and vis requirements put you lower and closer to the rocks ahead if you have to abort the approach at that point.

 

[flyboy102]

I see what you mean about the missed approach being initiated closer to the ground, however the missed instructions are identical on the two approaches...

 

[N801BH]

Out here we call it "Plan A and Plan B. If ya don't like what you see at A, progress to B..

Ben.
Jackson Hole Wy.

 

[gismo]

I see what you mean about the missed approach being initiated closer to the ground, however the missed instructions are identical on the two approaches...

Sorry, I should have been more clear. The difference is in Note 2 on the Jepp chart which appears just below the missed approach instructions. It reads: "Missed approach obstructions require a minimum climb gradient of 245'/NM to 11,200; if unable to meet rate of climb see 11-1. And "11-1" refers to ILS or LOC Y RWY 19.

 

[flyboy102]

Oh ok, that makes sense, thanks for explaining!

 

[John Collins]

I'm planning on flying into Jackson Hole (KJAC), and after looking over the approaches I noticed something odd. ILS or LOC RWY 19 has two plates, Y and Z. On Y the minimums are higher, and there's a note saying fly visual at DH from 1.8 miles out...kind of like a non precision MDA. My question is, why do these two approaches exist? And when might you ever choose to fly Y instead of Z with lower minimums?

The difference between the two approaches is the Z has a lower DH and requires a higher climb rate on the missed approach segment.

The Y approach has a "Fly Visual 187 degrees 1.8 NM" segment. This approach has a DH at 612 ft. From the DA, the standard missed approach 200 ft/NM climb rate is applicable. The visibility requirement is 2 NM. Because the Fly visual note is included, the runway or other visual ques listed in FAR 91.179 need not be in sight for you to descend below the DH, but you must have flight visibility of 2 NM and you must maintain visual conditions.

If you have the 2 NM, the altitude and direction of flight is at the pilots discretion, as long as they remain in visual conditions, clear of clouds. Terrain is avoided visually. If you must execute a missed approach after the DH, you will not have the 200 ft/NM missed approach, and need to determine in advance what your plan is going to be. Bottom line is that you should be pretty sure you are going to complete the landing when you make your decision at the DA.

 

[OtisAir]

While you're there, stop by the million dollar bar! There is a million silver dollars laminated into the bar top and ceiling and the bar stools are saddles! It's been about 20 years since I was there so I hope it's still there.

 

[Ghery]

While you're there, stop by the million dollar bar! There is a million silver dollars laminated into the bar top and ceiling and the bar stools are saddles! It's been about 20 years since I was there so I hope it's still there.

It's been a few years for me, but a lot less than 20, and it was still there then (2002?).