KMSO ILS Y 11 Missed Approach

[sellener777]

Interpretation on this missed procedure. Thought I briefed it, but ran into confusion actually flying it. Went missed at 5000 several miles from threshold. Hit 6200ft well before airport and therefore nowhere near radial 150.

Kept the climb and a continous right turn till 8500 then a left to 9100.

So the right turn happened before the vor.

It was flown referencing naco plates and specifically the profile view.

I get straight out to 6200.....the rest was confusing to me.



The text reads better but still not sure of navigation after climbing through 6200. If im 2 miles from vor when i hit 6200, and start a right turn i would never intercept r150?

After looking it over my best guess is they want you to climb straight out till u hit r150 then follow r150 untill above 8500 (which in a jet u will be) before u turn left to vor. Unless Im missing something? Clear as mud?

[Medtner]

That was an interesting case.

You could do the right turn 2 miles before the VOR, but it'd have to be a very slight one to intercept R-150.

The confusion stems, afaik, from the lack of a clear missed approach point. Eyeballing it tells me that getting from 5000 to 6200, being a matter of seconds in a powerful jet, would happen before the VOR in most instances. If, however, the procedure called for the VOR to be a flyover point (a ring around the VOR-symbol), it would be clearer.

This is a very good question. It's not an academic point either - in a terrain like this it could be critical. If a small piston plane could barely get to 6200 before the VOR, and then turned the long way around 390 degrees to intercept, it could be an accident waiting to happen. SA would of course be needed, but having the VOR a flyover point, or at least specifying in the notes how to intercept the R-150 would make it clear as day, whereas this is, indeed, clear as mud.

BTW: looking at the ILS-Z rwy 11, I get an idea what have happened. The profile view shows the MAP visually starting before the runway, as on the ILS-Y. However, in the ILS-Z the MAP is at 211 feet AGL, which is basically at the runway environment, and thus a climbing right turn would take you past the VOR anyway.
The ILS-Y, in the top-down view, has the drawing of the missed start at the VOR, which isn't correct. The missed should be waaay before that, being at 1822 feet AGL. So there is a big inconsistency here, and thus it looks right if you only compare the drawing with the text. They may have neglected to take into accound the fact that a spectacular minimum (I'm tempted to call it a maximum) like that will mess up the missed approach procedure.

[Ray Salmon]

The missed approach point on an ILS is the DA. Notice they want you climbing straight ahead to 6200 ft before making a turn, then turning right to intercept the 150 radial and continuing the climb to 8500. Then they want you to make a LEFT turn towards the VOR while continuing the climb to 9100 ft. They clearly want you on the protected side of that hold which is the east side. It's also the sector with the lowest MSA. If you reach 6200 before the 150 radial, then I would continue the climb straight ahead until crossing the 150 radial, then make a right turn to intercept it as depicted by the curved dotted line. Once you reach 8500, then start a left turn towards the VOR as instructed. Making an intercept turn to join the 150 radial (above 6200) before reaching the VOR would also comply with the textual instructions, but I wouldn't make the turn too early.

The procedures are designed to minimum TERPS criteria which is about 152 ft/nm on a missed approach climb (unless a steeper climb gradient is required, which is where the ILS Z 11 comes in). That's why this approach has such a high DA. You can't get the altitude needed for the missed approach using standard TERPS criteria unless you start the climb at 5022 ft. At DA, you're about 7.7 DME from the MSO VOR. Doing the math at 152 ft/nm, you're reaching 6200 ft right as you cross the VOR.

[rtataryn]

Yeah, the missed approach drawing on the plan view is completely off if you're flying anything other than an anemic piston on a hot summer day. By only looking at the graphic on the plan view you'd expect to execute the missed after the VOR and then keep the right turn going until intercept. No way that would happen in a jet. I've flown this approach before RW in a Turbo Cirrus and hit 6200 ft well before the VOR. It's a slight right turn to intercept the 150R while climbing and then at 8500 ft make an immediate left turn direct to MSO to hold at 9100. As always, the text version trumps any graphic version. I've seen several graphics out there on SIDs and approach plates that only add confusion. When in doubt, the text takes priority.