IFR Approaches - "We're just up havin' fun"( Full ATC)

[wayneda40]

Today good friend Blake and I shoot a couple approaches through the marine layer. As we approached the first final approach course we were too fast in trail of a Cherokee, so received a vector back around… and then 3 scheduled flights got priority... so back around, and back around again. But, hey, no complaints here… we’re just up havin’ fun! Welcome aboard! Wayne, GeezerGeek Pilot

 

[luvflyin]

Today good friend Blake and I shoot a couple approaches through the marine layer. As we approached the first final approach course we were too fast in trail of a Cherokee, so received a vector back around… and then 3 scheduled flights got priority... so back around, and back around again. But, hey, no complaints here… we’re just up havin’ fun! Welcome aboard! Wayne, GeezerGeek Pilot

When I saw Southwest at the terminal I said huh? I see they been flying in there for a few months now. Anyway, were you aware the Approach Clearance at SBA was illegal?

 

[wayneda40]

When I saw Southwest at the terminal I said huh? I see they been flying in there for a few months now.

SBA has done a nice job over the past few years in picking up flights (incl as you note, most recently Southwest) to useful locations (PHX, ORD, DEN, DFW, SEA etc).

Anyway, were you aware the Approach Clearance at SBA was illegal?

Interesting... what element of the clearance? Separation?

Thanks for checking in,
Wayne

 

[luvflyin]

SBA has done a nice job over the past few years in picking up flights (incl as you note, most recently Southwest) to useful locations (PHX, ORD, DEN, DFW, SEA etc).


Interesting... what element of the clearance? Separation?

Thanks for checking in,
Wayne

You were west of HABUT when the clearance was given. Not on a published segment. Controller is required to include an altitude to maintain until established on a published segment. No real big thing here, but if you are ever in the goo in an unfamiliar area I would think twice before just accepting a clearance like that.

 

[wayneda40]

You were west of HABUT when the clearance was given. Not on a published segment. Controller is required to include an altitude to maintain until established on a published segment. No real big thing here, but if you are ever in the goo in an unfamiliar area I would think twice before just accepting a clearance like that.

I see that now at 07:55, and indeed no "maintain x000 until established" was issued. In this case our prior altitude instruction was "maintain 3000" and we were well below the glideslope, so descending was not in the cards. A good heads up on your part. Thx.

 

[luvflyin]

I see that now at 07:55, and indeed no "maintain x000 until established" was issued. In this case our prior altitude instruction was "maintain 3000" and we were well below the glideslope, so descending was not in the cards. A good heads up on your part. Thx.

Yeah. Let’s say you didn’t have Glideslope and were doing the LOC and you were of the ‘dive and drive’ crowd. Would you have started the ‘dive’ right at HABUT? Starting out 500 feet lower than the Approach was designed for?

 

[midlifeflyer]

Yeah. Let’s say you didn’t have Glideslope and were doing the LOC and you were of the ‘dive and drive’ crowd. Would you have started the ‘dive’ right at HABUT? Starting out 500 feet lower than the Approach was designed for?

Sure, I would have "dived" all the way from the "maintain 3,000" down to 2,700 after crossing HABUT.

 

[luvflyin]

Sure, I would have "dived" all the way from the "maintain 3,000" down to 2,700 after crossing HABUT.

Lol. Yeah, that was kinda dramatic of me. Just tryin to illustrate a point.

 

[midlifeflyer]

Lol. Yeah, that was kinda dramatic of me. Just tryin to illustrate a point.

You are right that the controller should have said the altitude. But I think there are a number of these in procedure instructions/clearances where the statement is a bit of belt and suspenders (perhaps needed). Most of the time it simply states what we should do if it weren't stated - maintain the last assigned altitude until on a published course.

 

[luvflyin]

You are right that the controller should have said the altitude. But I think there are a number of these in procedure instructions/clearances where the statement is a bit of belt and suspenders (perhaps needed). Most of the time it simply states what we should do if it weren't stated - maintain the last assigned altitude until on a published course.

Yup. The redundancy is built into the system

 

[RussR]

This approach (SBA ILS OR LOC RWY 7) actually is a bit tricky and requires the pilot to be on their toes anyway.



If you look at the altitudes at GOYED and HABUT, they aren't very much below the glideslope. Rather, they're flirting with the maximum descent gradient allowed in the intermediate segment, which is 3 degrees (same as the glideslope here), or 318 ft per nm.

From GOYED to NAPPS is 2.9 nm: 2.9 x 318 = 922 ft, which means the glideslope at GOYED is at about 2722 ft - just barely above you at 2700.
From HABUT to GOYED is 3.4 nm: 3.4 x 318 = 1081 ft, which means the glideslope at HABUT is at about 2722+1081= 3803 ft.

Throw in a little altimeter error and a little bit of delay in starting a descent (from either fix), and poof! You're intercepting the glideslope from above.

My normal procedure would be to just maintain 3500 (or 3000 if that's how I was cleared as in the example) until glideslope intercept, then fly it down. This is one procedure where that would work really well, and avoid those other problems.

 

[luvflyin]

This approach (SBA ILS OR LOC RWY 7) actually is a bit tricky and requires the pilot to be on their toes anyway.

View attachment 98065

If you look at the altitudes at GOYED and HABUT, they aren't very much below the glideslope. Rather, they're flirting with the maximum descent gradient allowed in the intermediate segment, which is 3 degrees (same as the glideslope here), or 318 ft per nm.

From GOYED to NAPPS is 2.9 nm: 2.9 x 318 = 922 ft, which means the glideslope at GOYED is at about 2722 ft - just barely above you at 2700.
From HABUT to GOYED is 3.4 nm: 3.4 x 318 = 1081 ft, which means the glideslope at HABUT is at about 2722+1081= 3803 ft.

Throw in a little altimeter error and a little bit of delay in starting a descent (from either fix), and poof! You're intercepting the glideslope from above.

My normal procedure would be to just maintain 3500 (or 3000 if that's how I was cleared as in the example) until glideslope intercept, then fly it down. This is one procedure where that would work really well, and avoid those other problems.

Interesting Approach. You are supposed to comply with the altitude at GOYED and yeah, on a hot day you may have to get back down to the Glideslope. I’m really scratchin my head trying to figure out why GOYED is even there. Below a pic of that Approach from a longtime ago. No new significant terrain or obstructions. And look at the RNAV (GPS) RWY 7 Approach. ECEVA is at the same place as HABUT.

 

[midlifeflyer]

My normal procedure would be to just maintain 3500 (or 3000 if that's how I was cleared as in the example) until glideslope intercept, then fly it down. This is one procedure where that would work really well, and avoid those other problems.

My variation on your normal is to look at the glideslope needle when it activates on the extended FAC. If it is above me (so far it always is but I try to expect the unexpected) I hold altitude. Pretty much given up diving down to intercept altitude.

 

[luvflyin]

My variation on your normal is to look at the glideslope needle when it activates on the extended FAC. If it is above me (so far it always is but I try to expect the unexpected) I hold altitude. Pretty much given up diving down to intercept altitude.

If the Glideslope took you below 2700 before reaching GOYED, would you stay on it?

 

[RussR]

Interesting Approach. You are supposed to comply with the altitude at GOYED and yeah, on a hot day you may have to get back down to the Glideslope. I’m really scratchin my head trying to figure out why GOYED is even there. Below a pic of that Approach from a longtime ago. No new significant terrain or obstructions. And look at the RNAV (GPS) RWY 7 Approach. ECEVA is at the same place as HABUT.

The reason for the intermediate stepdown fix at GOYED is due to the high terrain north of the course. The evaluated area for an ILS intermediate segment starts at 4 nm either side of centerline, with an additional 2 nm secondary area ("buffer") at the IF (HABUT). This width shrinks down starting there until reaching the FAF.

Just a simple measurement using Skyvector shows that the high terrain starts closer than 6 nm from the course.

How old is that other chart you have (without GOYED)? If it's old enough, the criteria may have changed (although the criteria for VOR/ILS intermediate segments hasn't changed for a long, long time).

For RNAV (GPS) procedures, the width at the Intermediate Fix is 2 nm either side of centerline, with a 1 nm secondary area. So, half the width of a VOR/ILS procedure. Therefore, the RNAV (GPS) RWY 7's area is nowhere close to that high terrain and a stepdown fix is not needed.

 

[Palmpilot]

If the Glideslope took you below 2700 before reaching GOYED, would you stay on it?

I'm going to predict that his answer will be "no," because I'm pretty sure that he is aware of the airline pilots who were sanctioned for doing that outside a stepdown fix on approach to LAX.

 

[Daleandee]

W.W.J.W.D.?

What would Jerry Wagner do?

 

[luvflyin]

The reason for the intermediate stepdown fix at GOYED is due to the high terrain north of the course. The evaluated area for an ILS intermediate segment starts at 4 nm either side of centerline, with an additional 2 nm secondary area ("buffer") at the IF (HABUT). This width shrinks down starting there until reaching the FAF.

Just a simple measurement using Skyvector shows that the high terrain starts closer than 6 nm from the course.

How old is that other chart you have (without GOYED)? If it's old enough, the criteria may have changed (although the criteria for VOR/ILS intermediate segments hasn't changed for a long, long time).

For RNAV (GPS) procedures, the width at the Intermediate Fix is 2 nm either side of centerline, with a 1 nm secondary area. So, half the width of a VOR/ILS procedure. Therefore, the RNAV (GPS) RWY 7's area is nowhere close to that high terrain and a stepdown fix is not needed.

1980. I wouldn’t have thought there would be that much difference between a Localizer and GPS. A VOR radial, yeah.

 

[midlifeflyer]

If the Glideslope took you below 2700 before reaching GOYED, would you stay on it?

I'm going to predict that his answer will be "no," because I'm pretty sure that he is aware of the airline pilots who were sanctioned for doing that outside a stepdown fix on approach to LAX.

The prediction is correct but the reason is not.

My answer is "no" because I know you can't go below step-down minimums outside the PFAF, independent of whether some other pilots were sanctioned because they didn't know that.

 

[midlifeflyer]

W.W.J.W.D.?

What would Jerry Wagner do?

Funny you mention that because his ubiquitous 28R approach into OAK is pretty much the poster child for stepdowns outside the FAF. This is the ILS but the RNAV is pretty much identical.

 

[Palmpilot]

The prediction is correct but the reason is not.

My answer is "no" because I know you can't go below step-down minimums outside the PFAF, independent of whether some other pilots were sanctioned because they didn't know that.

The LAX enforcement is what made many of us aware of the issue, and I figured that you had seen the threads about it. I didn't mean to imply that the requirement was unknown to you before that.

 

[RussR]

1980. I wouldn’t have thought there would be that much difference between a Localizer and GPS. A VOR radial, yeah.

The difference isn't between the localizer and the GPS. Rather, it's between VOR and GPS. The starting width of the ILS/LOC intermediate segment is the same as the starting width of a VOR Intermediate segment, because before you get to the Localizer, you're on some kind of a segment based on VOR (like in this case - either from LOBER or GVO). And those widths start out at the 4+2 either side of centerline, tapering down once you turn onto the localizer, down to the localizer width at the FAF.

 

[AlleyCat67]

I would have gotten nervous being vectored out over open ocean for so long in a single engine. But I guess if you fly SBA, you have to get used to that.

 

[luvflyin]

The difference isn't between the localizer and the GPS. Rather, it's between VOR and GPS. The starting width of the ILS/LOC intermediate segment is the same as the starting width of a VOR Intermediate segment, because before you get to the Localizer, you're on some kind of a segment based on VOR (like in this case - either from LOBER or GVO). And those widths start out at the 4+2 either side of centerline, tapering down once you turn onto the localizer, down to the localizer width at the FAF.

Hmm. Do you think adding the Lead Radial is what triggered it?

 

[Palmpilot]

I would have gotten nervous being vectored out over open ocean for so long in a single engine. But I guess if you fly SBA, you have to get used to that.

The instructor I used for the instrument rating referred to the Monterey ILS as "the shark approach."

And up here, if the sharks don't get you, the water temperature probably will.