All things equal - which approach are you taking

[midlifeflyer]

We do RNAV RNP approaches down to RNP 0.10 and with RF-legs.

Some of us can do GLS approaches which are a form of LAAS, though they call it something else now.

The E-175 can do LPV approaches but not RNP, AFAIK.

I'm sure that's all correct.

 

[TCABM]

Airlines already run on razor thin profit margins. They’re not going to spend money on things that they don’t see financially fit for the operation.

8% (DL’s 2023 full year number) ain’t bad; a lot of auto/property insurers hope to get half that to call it a good year.

 

[orca64]

Simple question - i think?

Let's say I am flying into an airport, weather is going to be OVC005 and the airport publishes an ILS and RNAV approach into the favored runway. All approaches have mins of 200' AGL - all approaches basically have the same published missed - climb straight to 1500, left turn to 3000 to hold (The ILS has a heading - the RNAV is a direct to .. but both to the IAF/IF basically). Nothing NOTAM'd INOP and the aircraft is well equipped to handle basically anything. The ILS even has a feeder similar to the T structure of the RNAV - so no difference there either.

So which approach would you choose? ground based or space based? If weather is low with rain etc, do you gain efficiency or reliability using one versus the other? Anything else I'm not considering?

ILS.

There are no CAT 2 or CAT 3 RNAV approaches. There never will be.

Simple, easy to fly, extremely accurate, very difficult to spoof by external means. No worries about area outages or signal degradation.

No modern navigational equipment needed. You don’t have to load the approach in the box. Just TIM, and fly the bars down to minimums.

So easy, even a cave man can do it.

 

[kaiser]

Fantastic discussion! it gave me lots to consider. I ended up deciding on the RNAV, as well as a 2nd pilot. The trip went well and we landed with OVC004 and "reported" 2 1/2 sm viz with mist - though I think it was probably closer to 1 3/4 miles before i caught the lights (on high!!!). Lowest viz approach ever for me I think - very fun.

Either way, the one thing I did discover is that regardless of the approach, nothing beats having a 2nd pilot to tell you when they have the lights / runway in sight. Made the whole thing super simple and allowed us to catch it above DA. I suppose single pilot I'd just look up right at DA and hope to see something, but when #2 said lights in sight, I looked up and it definitely took me a good 3 seconds to catch them.

 

[eman1200]

weird, that 2nd pilot wasn't me............. hhhmmmfff

 

[kaiser]

weird, that 2nd pilot wasn't me............. hhhmmmfff

move to chicago!

 

[ja_user]

With some avionics suites/installations, there is no difference in the button pushing between either approach. Not in the setup, the missed or anything else. Yes the needles turn green for ILS, but you also have to make sure the magenta sequences, so it really doesn't matter... You take whichever is getting advertised...

Now where is this airport where there are no Notam's impacting the approaches?

 

[midlifeflyer]

You take whichever is getting advertised

why?
Perhaps you always take what’s advertised. I ask for what I want.

 

[ja_user]

why?
Perhaps you always take what’s advertised. I ask for what I want.

Unless there is a compelling reason, sure… it makes little difference

 

[midlifeflyer]

Unless there is a compelling reason, sure… it makes little difference

We all have our own choices.

Besides I see way too many pilots who are not assertive with ATC, so I wish more asked just as an exercise. I get looked at funny by trainees when I tell ATC what I want. I remember a 20 gazillion hour retired airline pilot who was shocked when I once asked for a different runway than advertised. Who ever heard of such a thing?!?!

 

[ja_user]

We all have our own choices.

Besides I see way too many pilots who are not assertive with ATC, so I wish more asked just as an exercise. I get looked at funny by trainees when I tell ATC what I want. I remember a 20 gazillion hour retired airline pilot who was shocked when I once asked for a different runway than advertised. Who ever heard of such a thing?!?!

Oh I agree on that completely, ask for what you want/need. Happens all the time, no big deal.


Back to the original topic, I really like some of the newer GPS/ILS approaches that use the same fix names for FAF, etc. Makes the controller jobs easier, and less confusion then them clearing you to a fix on the GPS, when you have the ILS loaded, etc..

 

[midlifeflyer]

Back to the original topic, I really like some of the newer GPS/ILS approaches that use the same fix names for FAF, etc. Makes the controller jobs easier, and less confusion then them clearing you to a fix on the GPS, when you have the ILS loaded, etc..

You might also begin to see a lot more controller use of approach clearances direct to the IF instead of vectors to intercept final as they get more appreciative of the reduction of workload that gives them without impacting on traffic flow.

 

[jordane93]

8% (DL’s 2023 full year number) ain’t bad; a lot of auto/property insurers hope to get half that to call it a good year.

Yea but they still generally won’t spend money on things that they don’t think will have a decent ROI

 

[TCABM]

Yea but they still generally won’t spend money on things that they don’t think will have a decent ROI

Very few companies will.

Honestly, I was just surprised DL’s margin was as high as it was last year. For perspective, Walmart ran a 2% net profit margin in 2023; BofA ran 24% for the same year.

 

[mryan75]

RNAV backed up by ILS.

This is the correct answer.

 

[flyingcheesehead]

The interior regions of the US have had about all the ILS approaches shut down 5 years ago except the MON airports.

Huh?

I'm in the "interior regions of the US" and I'm not aware of any ILS approaches being decommissioned yet, and I just went and looked and even the ones I've flown to podunk uncontrolled municipal airports are still there.

Yes, they will go away if not enough people fly them. Military or air carrier service, significantly better minimums (>50ft), and at least 6200 operations using them per year will be kept. GA airports where they get used <1400 times per year, they'll go away. In between, remains to be seen.

But, if there's an LPV approach with the same minimums, I'd rather the FAA decommission the ILS and spend all the money it takes to maintain them (I've heard ~$1 million per year) for something more useful, like certifying an unleaded universal replacement for 100LL.

ILS on the Block - IFR Magazine

In 2015, the FAA began looking to rationalize ILS approaches. In this context, rationalize means cut. The following year, the FAA developed a cost/benefit quantitative model and conducted an analysis at about 2900 airports with few or no RNAV SIDs or STARs. The finished product was a plan to...

www.ifr-magazine.com

Dial ILS freq in the receiver. Follow the needles. Couple autopilot if available.

I don't think that it takes less to set-up and activate an RNAV approach.

RNAV: Load the approach.
ILS: Load the approach, verify (and possibly tune, depending on your equipment) the frequency, turn the marker beacons back on on your audio panel, wait until you're in range, verify the ID, wait until you're on vectors or intermediate leg, switch to green needles and verify course guidance, switch autopilot to APR again if you were already cleared for the approach.

It's not hard to fly an ILS, but it absolutely takes less to set up and activate an RNAV approach and there are plenty of potential stumbling blocks, some of which cannot be done until the last couple of minutes prior to the FAF.

As such, I don't think I've flown an ILS in my personal airplane since 2017 outside of currency/IPC flights. RNAV all the way.

 

[John Collins]

Huh?

I'm in the "interior regions of the US" and I'm not aware of any ILS approaches being decommissioned yet, and I just went and looked and even the ones I've flown to podunk uncontrolled municipal airports are still there.

Yes, they will go away if not enough people fly them. Military or air carrier service, significantly better minimums (>50ft), and at least 6200 operations using them per year will be kept. GA airports where they get used <1400 times per year, they'll go away. In between, remains to be seen.

But, if there's an LPV approach with the same minimums, I'd rather the FAA decommission the ILS and spend all the money it takes to maintain them (I've heard ~$1 million per year) for something more useful, like certifying an unleaded universal replacement for 100LL.

ILS on the Block - IFR Magazine

In 2015, the FAA began looking to rationalize ILS approaches. In this context, rationalize means cut. The following year, the FAA developed a cost/benefit quantitative model and conducted an analysis at about 2900 airports with few or no RNAV SIDs or STARs. The finished product was a plan to...

www.ifr-magazine.com

RNAV: Load the approach.
ILS: Load the approach, verify (and possibly tune, depending on your equipment) the frequency, turn the marker beacons back on on your audio panel, wait until you're in range, verify the ID.

It's not hard, but it is more.

I agree, but there are even more ways to mess up an ILS, especially if you are using automation. The ILS frequency needs to be tuned and made the current frequency in the Nav Receiver. The CDI has to be changed to select VLOC when on final and back to GPS during the missed approach. There are just more things the pilot needs to do or consider with an ILS that doesn't need to be accomplished with an LPV. Once you are on the GS or GP, things are the same, at least until the DA. I only practice ILS regularly as a backup to the case where LPV is unavailable.