How much are you really protected on an IAP

Well, the office is kind of slow today, so I figured I’d bring up some approach plate training.

For those of you that may be new or missed my other posts, I am an Instrument Procedures Designer. None of my work is done in the United States, but foreign procedures instead.

So, have you ever wondered, while flying an IAP to your destination airport, possibly through a think cloud layer in which you couldn’t see out the windows and wonder “how much error/protection is built into this procedure to keep me from slamming into the mountains or cell phone towers I know are out there?”

Well the answer, quite a bit actually. Below are three procedures with both the areas overlayed on google earth and the approach plate.

First up SEQM ILS Y RWY 18

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In this approach, you can see that there are mountains and dangerous terrain all around you, how much space do we give a pilot for any error that may occur? Well, that’s some very complicated math depending on the approach type but here is the visualization. With this, the plane is in the center of each segment.

For this overlay, I have removed the MSA and holding patterns as they blocked the view of the approach.

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Next up is SPJC VOR Y RWY 15

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With this overlay, I left the MSA up on one of the attachment so you can visualize what that looks like when using that during your flying. I once again, removed all holding patterns.

With MSA.

Without MSA

And finally, everyone’s second favorite airport
TNCM RNAV GPS RWY 10

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And the overlay, with holdings removed.

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On each of these you will see three different colors, which represent different portions of the approach. You will also see the fixes and you can use to know your position via the chart. Green is the Initial and Intermediate segments (IAF and IF) while blue is the final segment (FAF and circling). You may also notice that an approach only had half a side for circling, that is because for that approach, you are not authorized to circle where there is no blue. And then finally the yellow is the missed segment.

Got any questions? Let me know and I’ll do my best to answer them!

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Great post! I’ve always wondered this as I am starting my instrument training!

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You talk about MSA. Is it minimum safe altitude as shown at the top right corner on the chart?

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Yes, I am referring to that.

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How did you get into this business? this is really interesting lol

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It’s a long story, but basically I started to hate ATC and every day I walked into work I couldn’t wait to walk out. So a job became available and I applied. Was sent to school for it, which was extremely difficult and started working.

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He had me do all his math homework for him and somehow he got hired.

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I mean… it worked though

This is really cool and useful! Do you work for Jeppesen?

Our departure procedures recently got reviewed. Would you ever worry about climbouts being protected for a VFR aircraft conducting instrument approaches?

In what situation? VFR aircraft can fly IAPs all the time under there own navigation for practice but can also fly them with headings and such! If a VFR aircraft is flying in controlled airspace and wants to fly the approach on its own, then no separation service will be provided to the VFR plane meaning that, that plane has to watch out for other traffic. IFR departures are protected and usually restricted to a certain altitude or even a heading assignment!

I’m not really following what you’re saying.

I’m also curious how you know they were recently reviewed? That’s not something that is normally advertised.

Unless your referring to a flight check, that dude is testing the navaids.

I work for a global organization. Jeppesen has tried to recruit me, but until their pay increases, I won’t go there.

This career field is extremely small worldwide.

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Please tell me you remembered to charge your phone before it died?

Radar approaches with vectored climbouts.

We had flight check the other week as he was checking the new recommended altitudes. We had our QA review like we do every 2 years and NAVFIG came down for a TERPS review and some training for us. He said that he never worries about VFR. We asked because our climbouts for radar approaches are initially 800’ then 1500’ for approaches during VFR, straight to 1500’ when IFR.

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Yeah u can fly IAPs with vectors but don’t have to if you are a VFR aircraft!

Radar approaches are positive control meaning you are receiving headings and glidepath calls to runway threshold for PAR or headings to MDA for ASR they aren’t normal IAPs.

So what are we talking about? Radar approaches or IAPs? They aren’t the same thing! Yes, an ASR and PAR approach you receive instructions from ATC like every 5 sections! But, on an IAP, ATC give headings and altitudes u til established on the final approach course and then it’s your job to follow the glide slope down! ATC does give headings and altitudes to PAR and SAR approaches as well!

Our TERPS review was on both we also have an approach control, as we are class C, which always give vectors for ILS and such, we are instructed to always give radar vector departure procedures on either. I’ve only ever seen a published missed twice in my 2 years here.

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