Help with KOAK ILS 28R missed approach instructions

B

Beatle1967

Filing Flight Plan
Joined
Oct 26, 2019
Messages
12
Display Name
Display name:
Beatle1967
I’m looking for some help interpreting the missed approach from KOAK ILS 28R. I would post a link to the plate, but the forum won’t allow it because I am under 5 posts. In any case, the missed approach instructions are as follows:


Climb to 1900 then climbing right turn to 3000 on heading 340 and SGD VORTAC R-165 to REBAS /SGD 14.3 DME and hold.


It seems that unless I take more than 10 miles to climb to 1900 before turning to 340, there’s no chance of intercepting the SGD 165 radial. So what’s the deal? Is it expected that I proceed direct to REBAS after reaching 3000? The graphical depiction of the missed approach appears to be in conflict with the textual part.


Thanks in advance!
 
Last edited:
I think we may have discussed this there are actually several approaches where making the turn at the initial altitude will actually take you away from the radial.the general consensus was to be situationally aware and adjust to create a reasonable intercept. (Of course, the likelihood of actually flying the published missed in this approach is minimal, but that's not the question)
 
midlifeflyer said:
I think we may have discussed this there are actually several approaches where making the turn at the initial altitude will actually take you away from the radial.the general consensus was to be situationally aware and adjust to create a reasonable intercept. (Of course, the likelihood of actually flying the published missed in this approach is minimal, but that's not the question)
Click to expand...
This is my favorite in my area. The climb before the turn is only 445'. In a 172, you"d still be over the runway.
upload_2022-2-1_18-9-48.png
 
Interesting. From 440’ missed to 1900’ is a 1460’ climb.
Assuming my plane climbing at 95kt for 500fpm it would take around 3 minutes get you to just under 5 miles from the airport to reach 1900’.
Approximating distances on the chart between some of the fixes, you could see where the turn may bring you close enough for the gauges to pick up the radial and correct to find where you are heading. (Mental math-but I think I’m close)
 
To bottom line this- the turn to 340 should not be made upon reaching 1900, rather it should be delayed until the radial intercept is possible.
 
In these cases, the removal of the heading, allowing the pilot to choose an appropriate intercept heading, would be a better choice for the design.
 
@aterpster can probably confirm or deny this, but the missed approach procedure is based on a 200 ft/mile climb, so climbing from DA to 1900 feet would put you in a pretty good position for that shallow intercept angle. If your airplane climbs faster than that, you’ll end up with the confusion described.
 
MauleSkinner said:
@aterpster can probably confirm or deny this, but the missed approach procedure is based on a 200 ft/mile climb, so climbing from DA to 1900 feet would put you in a pretty good position for that shallow intercept angle. If your airplane climbs faster than that, you’ll end up with the confusion described.
Click to expand...
The procedures specialist designs for a climb gradient of 200 feet per mile starting at the MAP (DA point for ILS, usually threshold for NPA). Simple designs are not usually possible in highly congested Class B airspace. And, the "bet" is that ATC will intercede with vectors.
 
I get very close to 10 miles from MAP to the 165 radial. That’s based on the MAP being 1/2 mile from the runway threshold. I don’t know exactly what the Ground Point of Interception of the the Glideslope is, but I’m sure that 1/2 mile is going to be very close. I’m disregarding the 9’ airport elevation and calling it sea level. It’s a 3 degree Glideslope, so the ‘geographic’ location of DA is going to be very close to that. 1900-200(da) gives 1700 feet of climb needed before starting the turn. This is not like some Missed Approaches where the procedure will take you across a radial that you need to turn to get back on it.
upload_2022-2-2_8-26-11.png
 
midlifeflyer said:
This is my favorite in my area. The climb before the turn is only 445'. In a 172, you"d still be over the runway.
View attachment 104246
Click to expand...
That's one of them ones where it takes you through the radial and you have to get back to it. We dissected a couple of these here not all long that ago, but I can't find them. They gotta TERP it out assumming the 200 feet per mile thing. But yeah, in some combinations of slow speed and/or very high rates of climb, you ain't gonna go 'through' the radial. I suppose they could make the Missed Approach Procedure a couple paragraphs long with a buncha 'if's' to account for that some planes may not cross the radial with some alternate headings for those that don't. But I doubt it. So, like some other things, where it's not all wrapped up for you and all you have to do is follow the instructions by 'rote,' you have to 'think' and apply the 'logic check.'
 
Last edited:
luvflyin said:
That's one of them ones where it takes you through the radial and you have to get back to it. We dissected a couple of these here not all long that ago, but I can't find them. They gotta TERP it out assumming the 200 feet per mile thing. But yeah, in some combinations of slow speed and/or very high rates of climb, you ain't gonna go 'through' the radial. I suppose they could make the Missed Approach Procedure a couple paragraphs long with a buncha 'if's' to account for that some planes may not cross the radial with some alternate headings for those that don't. But I doubt it. So, like some other things, where it's not all wrapped up for you and all you have to do is follow the instructions by 'rote,' you have to 'think' and apply the 'logic check.'
Click to expand...

Perhaps this one with a 15,000' runway?
VCV ILS 17.jpg
 
luvflyin said:
That's one of them ones where it takes you through the radial and you have to get back to it. We dissected a couple of these here not all long that ago, but I can't find them. They gotta TERP it out assumming the 200 feet per mile thing. But yeah, in some combinations of slow speed and/or very high rates of climb, you ain't gonna go 'through' the radial. I suppose they could make the Missed Approach Procedure a couple paragraphs long with a buncha 'if's' to account for that some planes may not cross the radial with some alternate headings for those that don't. But I doubt it. So, like some other things, where it's not all wrapped up for you and all you have to do is follow the instructions by 'rote,' you have to 'think' and apply the 'logic check.'
Click to expand...

My preference would be to just leave the heading off. "Climb to 2000 then climbing right turn to 3000 to intercept the XXX R-YYY to ZZZZZ should be sufficient for any instrument-rated pilot. However, sadly it's probably not.
 
aterpster said:
Perhaps this one with a 15,000' runway?
View attachment 104266
Click to expand...
Yeah. That was one of them. Lot of talk about just where was the Missed Approach Point as I recall. The VCV VOR being so close seemed to be confusing things. And lotsa talk about if you have RNAV, why not just go direct to ETHER instead of getting back to the 269r.
 
RussR said:
My preference would be to just leave the heading off. "Climb to 2000 then climbing right turn to 3000 to intercept the XXX R-YYY to ZZZZZ should be sufficient for any instrument-rated pilot. However, sadly it's probably not.
Click to expand...
VCV ILS 17 would read like this:

"Climb to 3500, then climbing right turn to 6000 via heading to intercept VCV VOR/DME R-269 to ETHER INT and hold."

Or "...heading-to-intercept..."
 
RussR said:
My preference would be to just leave the heading off. "Climb to 2000 then climbing right turn to 3000 to intercept the XXX R-YYY to ZZZZZ should be sufficient for any instrument-rated pilot. However, sadly it's probably not.
Click to expand...
Yeah. There was one though that had you going through the radial(most planes anyway, real high performance climbers may not). After going through the radial, it was important to get back on the radial within a certain distance because of obstructions between the turn point and the next fix. A heading to join would probably be appropriate in that case.
 
RussR said:
In these cases, the removal of the heading, allowing the pilot to choose an appropriate intercept heading, would be a better choice for the design.
Click to expand...
Funny... in those I've tried, that's pretty much what a GPS-based missed approach does.
 
luvflyin said:
That's one of them ones where it takes you through the radial and you have to get back to it.
Click to expand...
Not on that one. As I drew it (and have flown it in a simulator), you'd never get to the radial at all by following the instruction.
 
midlifeflyer said:
Not on that one. As I drew it (and have flown it in a simulator), you'd never get to the radial at all by following the instruction.
Click to expand...
I didn't mean 'you' personally in your 172. The procedure is designed assuming planes will go through it though. Hence, the 015 heading.
 
The missed approach for the Rwy 25R ILS at Livermore (LVK) has a similar problem. Given that you only have to climb 600 feet above DA before turning, you would have to be flying a really poor climber for the prescribed 020 heading to get you to the OAK 060 radial before passing the holding fix, especially if there is any headwind.

LVK - 06075I25R.png
 
Palmpilot said:
The missed approach for the Rwy 25R ILS at Livermore (LVK) has a similar problem. Given that you only have to climb 600 feet above DA before turning, you would have to be flying a really poor climber for the prescribed 020 heading to get you to the OAK 060 radial before passing the holding fix, especially if there is any headwind.

View attachment 104279
Click to expand...
Yeah. That's a good one for the where exactly is the Missed Approach Point discussion if you miss early for some reason.
 
Last edited:
luvflyin said:
Yeah. That's a good one for the where exactly is the Missed Approach Point discussion if you miss early for some reason.
Click to expand...
Even if you miss at DA while established on the glideslope, there is a problem, based on the AATDs that I use. I've "flown" that missed many times, and it always requires fudging the heading after the initial turn. I even plotted it out once, using typical GA climb rates and speeds to confirm that the simulators were correct.
 
Palmpilot said:
The missed approach for the Rwy 25R ILS at Livermore (LVK) has a similar problem. Given that you only have to climb 600 feet above DA before turning, you would have to be flying a really poor climber for the prescribed 020 heading to get you to the OAK 060 radial before passing the holding fix, especially if there is any headwind.

View attachment 104279
Click to expand...
Oooh! That's a good one.
 
@Palmpilot you were saying (2 weeks ago, I know) that 020 would put you on the east side of ALTAM before you hit the 060 R?

From the diagram the 40 degree intercept doesn’t look that way (it’s not to scale, right?).

By “fudging the heading” you fly straight north a bit, or have direct ALTAM in the GPS or something like that?
 
Terry M - 3CK (Chicago) said:
@Palmpilot you were saying (2 weeks ago, I know) that 020 would put you on the east side of ALTAM before you hit the 060 R?
Click to expand...

It has happened that way every time I have "flown" that missed approach using my club's AATD (sim). Eventually I confirmed this by plotting it to scale, using reasonable assumptions for the climb performance and turn rate of a Cessna 182.

From the diagram the 40 degree intercept doesn’t look that way (it’s not to scale, right?).
Click to expand...

Comparing the approach plate to the sectional, it looks to me like the location of the holding fix is to scale. However the point at which the turn to the 020 heading is depicted does not take into account the climb performance of the average GA aircraft. The missed approach procedure calls for the turn to be initiated at a specific altitude, not a specific point over the ground. If the approach lights are not in sight at DA, then the climb will begin immediately after, and even with no wind, at 500 FPM and 90 knots it only takes 1.8 NM to climb from 600 MSL to 1200 MSL.

Of course headwind will make the problem even worse.

By “fudging the heading” you fly straight north a bit, or have direct ALTAM in the GPS or something like that?
Click to expand...

It would be easy with a GPS, but if you didn't have one, then in addition to the OAK VOR radial, you would need to have the OAK DME tuned in, or the SAC 177 degree radial (based on the sectional or enroute chart). Of course you should get ATC's concurrence with what you plan to do, or ask for a better vector than what's on the chart.

Or I suppose you could just play dumb and use the OAK DME to estimate when you should begin the inbound turn after you miss the holding fix. ;)
 
I was thinking the turn in a missed might be terrain avoidance too.

Climb until safe then turn to remain safe. Maybe not true there.
 
Terry M - 3CK (Chicago) said:
I was thinking the turn in a missed might be terrain avoidance too.

Climb until safe then turn to remain safe. Maybe not true there.
Click to expand...

The top of the ridge off the 25R departure end is about 7 NM away and less than 1400 feet above DA, so that wouldn't be a factor, given that the missed approach requires a minimum climb gradient of 358' per NM to 3600.
 
Livermore is an interesting study of ATC/FAA vs. the pilot. I have the records. The ILS used to have the same minimums as today without a climb gradient because the missed approach turned to the east and avoided all terrain. But, that caused heartburn for ATC. That resulted in the current design. And, the ILS 25R is supposed to have a line of minimums for those who cannot make the climb gradient. But, the FAA granted a waiver to that requirement.
 
aterpster said:
Livermore is an interesting study of ATC/FAA vs. the pilot. I have the records. The ILS used to have the same minimums as today without a climb gradient because the missed approach turned to the east and avoided all terrain. But, that caused heartburn for ATC. That resulted in the current design. And, the ILS 25R is supposed to have a line of minimums for those who cannot make the climb gradient. But, the FAA granted a waiver to that requirement.
Click to expand...
There's a note to use the localizer approach, which has higher descent minimums, if you can't make the climb gradient on the ILS chart.
 
Anytime I read about proper procedures operating out of of KOAK, I just ask myself, what would Jerry do? ;)
 
You must log in or register to reply here.
Back
Top