Step down approach question

[ricfly744]

Dear all,

Today, on my approach to KORD, I was given a base vector , an instruction to descent to 5000' and to intercept LOCALIZER to RWY 28C.
When stablished on LOC, at 5000' I was instructed: "CLEARED FOR THE APPROACH 28C".

The vertical profile for this approach, is on steps: 5000' to RZUKO, 4000' to HAZIL and 2300' at SEIKA, where the Malta Cross is, and where you get the glide slope.

Question: when cleared for the approach, at 5000', should I descent following the steps, and only intercept the GS at 2300' as by the chart, or I can maintain 5000' until I intercept the GS?
What ATC expects?

Thank you in advance for your time to answer.

[Btrbill]

The purpose of the 5000 foot turn on is to separate you from the aircraft joining the ILS finals to the other two runways. The rule is you have to be level at the altitude, established on final, and on a frequency with final monitor override prior to losing 1000 feet separation with those on the adjacent finals. The "stepdown" or crossing altitudes at the other fixes are designed to separate you from those turning final to the other runways.

To answer your question, it is completely legal for you to descend to those altitudes on the plates as you would normally do with any stepdown fix... however, most controllers are going to expect you to fly at 5000 until you join the GS and then to descend according to it.

I do not work at KORD, but I did work at both KDFW and KIAH, and they both also had triple simultaneous ILS approaches to parallel runways, just as KORD and KATL do.

Safe Skies!!

[jmmoric]

Btrbill: He was cleared to intercept the localizer at 5000', and then further cleared the approach when he was established.

That means he has to maintain 5000' intercept the localizer, and then follow the procedure as soon as he was given the approach clearance.

Every controller would expect a pilot to maintain 5000' until otherwise cleared... (the approach in this case when he was established)

One of many reasons: he was vectored above an aircraft on downwind at 4000', and there would be no room beneath until he was established.

Intercept localizer is not an approach clearance :)

[Btrbill]

jmmoric,

You said: "That means he has to maintain 5000' intercept the localizer, and then follow the procedure as soon as he was given the approach clearance."

Lets look at his statement...

"Today, on my approach to KORD, I was given a base vector , an instruction to descent to 5000' and to intercept LOCALIZER to RWY 28C.
When stablished on LOC, at 5000' I was instructed: "CLEARED FOR THE APPROACH 28C".

First off, he never would have given an instruction to intercept the localizer while on a base vector. Lets assume he was flying in from the north downwind... he would have been told, "Boeing744, Heavy, turn right heading 180, descend and maintain 5000 feet." When in position, he would have been told, "Boeing744, Heavy, turn right heading 250, intercept the 28C localizer." The reason he might not have been cleared here are many... Maybe the controller next to him working the 28R final was late in getting his guy turned in, so he asked the 28C guy to just have him join... maybe it is controller technique.. having worked this EXACT operation at two other airports, I have seen it all...

Once he was given his approach clearance, he is free to descend according to the stepdown fixes, REGARDLESS of where the GS is!!!

You said, "Every controller would expect a pilot to maintain 5000' until otherwise cleared... (the approach in this case when he was established)"

Not arguing that point at all. That was not his question though. His question was, "when cleared for the approach, at 5000', should I descent following the steps, and only intercept the GS at 2300' as by the chart, or I can maintain 5000' until I intercept the GS?"

My response was, "To answer your question, it is completely legal for you to descend to those altitudes on the plates as you would normally do with any stepdown fix... however, most controllers are going to expect you to fly at 5000 until you join the GS and then to descend according to it."

I am sorry if that confused you.

[MOE EDSK]

(When the fixes are part of the approach procedure IAF - IF - FAF)

If the step-down altitudes and the glide path intercept alt are (at) altitudes then you have to cross all the fixes and the GPIP at these altitudes. If the controller wants you to leave 5000ft on the ILS glide slope for whatever reason he has to state this specifically in the approach clearance.

If the altitudes are specified (at or above) then you are free to leave 5000ft on the ILS GS or fly the procedure as above or anything in between. Again, if the controller wants you to leave 5000ft on the ILS GS he has to include this in the approach clearance.

[mad_jock]

ricfly747.

Practically you have to double check with ATC as soon as you get the clearance.

There is no right answer, its very country dependant what they expect you to do. Sometimes keeping the 5k will put you stupidly over the glide if you don't descend to the platform height.

"confirm cleared to descend to XXXXft for glide intercept" would the question I would ask.

The reply's so far are what the posters would expect in their own country. As you well know the differences between country's can be quite marked.

The only thing you can do is ask.

[glendalegoon]

ONCE in a great while you will get information on an approach plate that makes you think

some are: MANDATORY ALTITUDES

some are at or above

We learned along time ago that you maintain your last assigned altitude UNTIL Absolutely ESTABLISHED on a PUBLISHED segment of an instrument approach. (Bless those poor TWA guys at IAD).

I do have one question for the first poster...Was your approach clearance: CLEARED ILS 28C? Was it: cleared LOCALIZER 28c, or was it cleared apch...


And here is a really good clue for next time. Get the phone number for apch control (maybe from clearance delivery on the ground) and call them up and ASK THEM what they expect you to do.

[jmmoric]

Btrbill: You're perfectly right, I re-read the question, and must admit I misunderstod the scenario :O

And you're right, once the approach clearance is given, the pilot can descend according to the procedure, unless otherwise restricted, IF in doubt, just ask :)

My answer still stands though, but to a completely different question :O

[naveedriaz69]

Hello, I ve just stumbled upon this thread while looking for LOC only appr tech.
The question was whether to fly the glide in a step descend or fly the glide slope throughout the appr. ILS's are flown on a fixed angle to clear all fixes at or above unless the fixes have mandatory altitudes to be at. And I agree, call the controller as clearances may differ country to country.

[aterpster]

In the U.S. the step-down fixes are controlling until the P-FAF.

The designers try to make flying the G/S to not bust those step-down fixes. But, on a very hot day it can happen.

It's obvious that most, if not all, those ILS stepdown fixes at ORD are not for obstacle clearance. Rather, they are to provide procedural separation from other traffic.

[piston2jet]

Given Scenario :

If we are making an ILS approach to a runway and trying to intercept the Localizer (the needle is full-scale deflection to the right), we see the Glide Slope needle coming alive and is now in the center. Our LOC needle is still far to the right, we then turn right a few more degrees to intercept it. In the mean while our GS needle deflects below the center line. Now at this moment :-

Q1 ) Can we put our a/c into landing configuration?

Q2) Can we descend below and follow the GS needle or should we wait for the LOC needle to be at least half-scale deflected and then descend rapidly to make up? ( The passengers can get scared and their ears would hurt)

Requesting members for their views & suggestions.

Thank your very much,

Regards
P2J