5 hours ago, ryanbatc said:

And most people may not know, that irl, many PAPIs are NOT coincident with the glideslope on the ILS.

Why would they do that? I thought there were calibration checks to ensure they are correct.

In the UK the Civil Aviation Authority (CAA) organises checks by specialist contractors to check all navigation equipment and lighting systems such as PAPI's. So what is the point if they don't coincide with each other and maybe give conflicting information?

2 hours ago, bobcat999 said:

Why would they do that?

Chatgpt knows:

Yes. It's true that many PAPI systems are intentionally not exactly coincident with the ILS glideslope. There are several reasons for this, and in many cases the difference is by design rather than an error.

The main reasons are:

Obstacle clearance

The PAPI may be set at a slightly higher angle than the ILS (for example, PAPI at 3.2° while the ILS is 3.0°).

This provides additional clearance over obstacles close to the runway threshold.

It also helps protect aircraft with lower cockpit heights.

Eye-to-wheel height

An ILS guides the aircraft based on the glideslope antenna, which effectively provides guidance for the aircraft's flight path.

A PAPI is designed so that the pilot's eyes see the correct indication.

Since different aircraft have different distances between the pilot's eyes and the landing gear ("eye-to-wheel height"), a single PAPI angle cannot perfectly suit every aircraft.

A slight offset helps ensure that the main landing gear crosses the threshold at an appropriate height.

Large aircraft considerations

Very large aircraft (e.g. wide-body jets) have much greater eye-to-wheel heights than small aircraft.

If they flew a standard PAPI exactly "on slope," their wheels might be lower than intended at the threshold.

Many operators of large aircraft therefore use procedures such as:

follow the ILS until visual,

then transition carefully to the visual aiming point,

or, at some airports, use specific guidance in the aircraft operating manual.

Independent design criteria

The ILS and PAPI are designed under different international standards.

The ILS glideslope is established by radio-navigation requirements.

The PAPI is positioned and adjusted according to visual guidance standards, runway geometry, threshold crossing height, obstacle environment, and operational needs.

Their design objectives overlap but are not identical.

How big is the difference?

Typically, the difference is small:

ILS: 3.00°

PAPI: 3.20°

or

ILS: 3.00°

PAPI: 2.95°

A difference of 0.1–0.3° is fairly common. While that sounds tiny, over several nautical miles it corresponds to tens of feet of altitude.

Which should a pilot follow?

In instrument meteorological conditions, pilots fly the ILS glideslope until reaching visual references at or below decision altitude. Once sufficient visual references are established, they transition to a normal visual landing, using cues such as the runway perspective and the PAPI.

If the ILS and PAPI don't agree, this isn't necessarily a malfunction. Pilots generally continue to fly the published instrument procedure until visual, and then use judgment while respecting any airport-specific procedures or aircraft limitations. If the discrepancy is unusually large or unexpected, it should be treated cautiously and, if necessary, reported.

In short, a PAPI and an ILS are not required to coincide exactly. They are separate guidance systems with different design criteria, and a small angular difference is often intentional to account for obstacle clearance, threshold crossing height, and the wide range of aircraft eye-to-wheel geometries.

18 hours ago, MattNischan said:

Just ILS. There is no globally available data source for PAPI positioning. Some notes I've made about this topic on the official forums about our work here this sim update:

And

So if I’m using payware airports with navigraph data I won’t see a change any way ?

5 hours ago, bobcat999 said:

Why would they do that? I thought there were calibration checks to ensure they are correct.

PAPI's are not part of the ILS. They are a VISUAL component to guide a pilot to the runway during final approach. That's where a lot of simmers are confused. In real life if you're flying an ILS to minimums you aren't even looking at the papi, you're looking at places on the runway itself for touchdown.... just slightly beyond the 1000 footers. The PAPI is more for a visual approach and assists with guiding you to that place.

@turbomax @ryanbatc

Got it! Thanks to both of you.

5 hours ago, turbomax said:

Chatgpt knows:

How do you know all of that is correct?

Edited July 17Jul 17 by Tuskin38

On 7/9/2026 at 10:57 PM, MarcG said:

So for you it's acceptable to continually release updates with regressions? Game breaking ones at that? Of which there is 6 years of evidence, all there on the internet to be seen.

Is it wrong to want standards to improve? Is it wrong to want a product/development team to get better in areas that it's/they are lacking?

Are you able to answer those questions in an adult manner, or is cheap sarcasm your only response?

Well, let's just say I'm not making a fuzz about it like you do most of the time. Of course it is not wrong to want a product to get better. That's what I want too, there is still a lot of room for improvement. But again, I do not know what is going on behind the scenes, I can not even start to imagine how complex this software is. So how would I be able to judge the skills of Asobo? How would it help in any way if I call the developers incompetent? In my view your judging and degrading comments about the team do not really contribute much to solving the issues. But that's just me 😉
I'm pretty satisfied with the lack of sarcasm in my reply. How about you?

1 hour ago, Tuskin38 said:

How do you know all of that is correct?

Judgement, cross checks, natural intelligence, prayers. 😄

How do I know all of avsim posts are correct?

Edited July 17Jul 17 by turbomax

59 minutes ago, Rimshot said:

Well, let's just say I'm not making a fuzz about it like you do most of the time. Of course it is not wrong to want a product to get better. That's what I want too, there is still a lot of room for improvement. But again, I do not know what is going on behind the scenes, I can not even start to imagine how complex this software is. So how would I be able to judge the skills of Asobo? How would it help in any way if I call the developers incompetent? In my view your judging and degrading comments about the team do not really contribute much to solving the issues. But that's just me 😉
I'm pretty satisfied with the lack of sarcasm in my reply. How about you?

I just find the acceptance of blatant shortcomings to be extraordinary, it's that acceptance that equates to poor development strategies because the developers think "oh well it's good enough", well it's not good enough to constantly release updates with regressions that affect peoples enjoyment of the software....6 years and counting.

My frustration and annoyance with Asobo is driven by my love for the product, no different to shouting at the TV when the head coach of my favourite football team makes a substitution and we go on and lose the game! It's the same thing, it's the same obvious areas that just smack you in the face and you wonder "why" can't they see it the same.

BTW I've done my time sending in bug reports, posting in the bug threads on the official forum, so yes I have tried to play a part but eventually I just gave up when the same mistakes, issues and downright ignoring kept happening.

Finally, as said a hundred times, MS/Asobo have been brilliant on one hand and inept on the other - but I still have absolutely brilliant moments in the game regardless. 🙂

4 hours ago, fakeflyer737 said:

So if I’m using payware airports with navigraph data I won’t see a change any way ?

I don't know what Navigraph does as far as harmonizing the data with the simulator scenery. The stock data build process has the benefit of having all of the scenery on hand in source form when building the navdata. You will still see the fixes to the ILS radio for erroneous deviation swings near the last 100ft or so, as that is an issue in the sim radio itself.

But the rest of the issues are just how the navdata relates to the actual scenery (and, to the real world). Lots of the data in the ARINC for ILS is actually not needed for aircraft at all, it's only there for simulation purposes. The antenna position (vertical and lateral) is not required for avionics IRL, as they just tune the radio. So, these things don't get surveyed particularly often, and as budgets get tighter the intervals get longer and accuracy gets worse. So, there are a great many cases where the ARINC data says the runway bearing is X, but the ILS bearing is Y, and it's possible neither of them are actually the real bearing exactly. Or the antenna position is some lat/lon/alt, but if you look at the TCH, that can't be true with either the in-sim scenery runway end height and/or the ARINC runway height.

As a result, the navdata in this case cannot possibly be the source of truth, when all of those truths add up to something that isn't internally consistent or consistent with the sim scenery. So, now, during the stock navdata build process, we're fine tuning those data points to align with the actual sim scenery.

2 hours ago, MarcG said:

My frustration and annoyance with Asobo is driven by my love for the product, no different to shouting at the TV when the head coach of my favourite football team makes a substitution and we go on and lose the game! It's the same thing, it's the same obvious areas that just smack you in the face and you wonder "why" can't they see it the same.

I think England's second half against Argentina falls into that category. Every man/woman/child/dog/cat/armadillo on the planet except Thomas Tuchel knew that trying to defend a 1-0 lead was suicidal.

24 minutes ago, Christopher Low said:

I think England's second half against Argentina falls into that category. Every man/woman/child/dog/cat/armadillo on the planet except Thomas Tuchel knew that trying to defend a 1-0 lead was suicidal.

Precisely my point!

16 hours ago, MarcG said:

I just find the acceptance of blatant shortcomings to be extraordinary, it's that acceptance that equates to poor development strategies because the developers think "oh well it's good enough", well it's not good enough to constantly release updates with regressions that affect peoples enjoyment of the software....6 years and counting.

My frustration and annoyance with Asobo is driven by my love for the product, no different to shouting at the TV when the head coach of my favourite football team makes a substitution and we go on and lose the game! It's the same thing, it's the same obvious areas that just smack you in the face and you wonder "why" can't they see it the same.

BTW I've done my time sending in bug reports, posting in the bug threads on the official forum, so yes I have tried to play a part but eventually I just gave up when the same mistakes, issues and downright ignoring kept happening.

Finally, as said a hundred times, MS/Asobo have been brilliant on one hand and inept on the other - but I still have absolutely brilliant moments in the game regardless. 🙂

Your statement mirrors my position exactly. I couldn't have put it better.

didn't see it mentioned in the patch notes, but what ever issue was shrinking the click spots on the A300 and A310 is fixed.