Product= XPlane
Version= 11.31r1
OS= Windows
Summary= ILS Heading Deviation
Description= Default airport MMUN ILS for Runway 12L. Charts show a heading of 125 however this heading with no wind placed the plane just to the left of the runway. Once the plane was on the runway and aligned down the centerline the heading on the PFD displayed 126. I believe the default airport info needs to be moved one degree over.
Steps= No changes fresh install default planes
Consents to storing personal data= Yes
Using WED 2.0 and the "navaids" layer it can quickly be seen that the ILS does line up reasonably with the existing runways for the recommended version (and even all newer and declined versions) of the airport. Granted, it could be 30 or 50 feet better, but real-world CAT-I ILS accuracy at the threshold is only required to be +/- 10.5m. So @Robin could move the ILS LOC a bit south here, as imagery shows the runway is dead on and the ILS LOC antenna concrete foundations are visible.
Problems like this can be exaberated (or even be caused) by a number of issues including from using 3rd party airports, 3rd party navaid data, 3rd part aircraft (that may not use X-plane navaid data at all) and in many other cases the users unfamiliarity with autopilot or ILS operations. The later may be the case here - as ILS landings can NOT be successfull with the autopilot in heading mode.
Any discrepancy in magnetic heading displayed in X-plane vs any offical charts also depends on the magnetic variation model used in the simulator - which may differ by a (very few, usually just a few 10th) degrees for any given place in the world. So if the PFD display rounds that heading to 126, which charts round it to 125 - that can be caused by miniscule differences, even the annual change in deviation (which is NOT modelled in X-plane) can cause such discrepancies in just 2-3 years. The ILS heading in the scenery aligns with the runway down to one or two hundredth of a degree - so that as dead on as it gets.
P.S. If a pilot does autoland on a CAT-I ILS and does not go around or sidestep to the runway upon reaching decision height - that is always pilot error ... so lets call it a very good real-world training setup until the navaid is fine-tuned.
Thanks! The update to MMUN ILS 12L will be included in the next release of X-Plane that includes updated ILS data. It seemed as if all the ILS data had been shifted a few yards to the north east. - Robin
-------- Original Message --------
Subject: Bug report: Cancun Airport - Mexico
Date: Tue, 8 Jul 2014 11:57:39 -0400 (EDT)
From: marino.mugnaini@alice.it
To: bugreports@x-plane.com
From= marino.mugnaini@alice.it
IP= 79.21.52.241
Product= XPlane
Version= 10.25
OS= Windows
Summary= Cancun Airport - Mexico
Description= Hallo Ben,
this is the runway MMUN 12L (INCP freq. 110.70 MHz).
Perhaps a bug??
Steps= Normal fly.
Jennifer Roberts November 3, 2015 2:19 PM
Needs an exclusion zone added then uploaded to Gateway.
Jan Vogel February 23, 2021 8:32 AM
This airport has been updated in the meantime, this bug report can be closed.
Product= XPlane
Version= 11.31r1
OS= Windows
Summary= ILS Heading Deviation
Description= Default airport MMUN ILS for Runway 12L. Charts show a heading of 125 however this heading with no wind placed the plane just to the left of the runway. Once the plane was on the runway and aligned down the centerline the heading on the PFD displayed 126. I believe the default airport info needs to be moved one degree over.
Steps= No changes fresh install default planes
Consents to storing personal data= Yes
Jennifer Roberts February 20, 2019 4:55 PM
Hi Julian,
Can you clarify why this is not a bug? Do both the airport & navaid current locations match official sources?
Michael Minnhaar February 20, 2019 6:31 PM
Using WED 2.0 and the "navaids" layer it can quickly be seen that the ILS does line up reasonably with the existing runways for the recommended version (and even all newer and declined versions) of the airport. Granted, it could be 30 or 50 feet better, but real-world CAT-I ILS accuracy at the threshold is only required to be +/- 10.5m. So @Robin could move the ILS LOC a bit south here, as imagery shows the runway is dead on and the ILS LOC antenna concrete foundations are visible.
Problems like this can be exaberated (or even be caused) by a number of issues including from using 3rd party airports, 3rd party navaid data, 3rd part aircraft (that may not use X-plane navaid data at all) and in many other cases the users unfamiliarity with autopilot or ILS operations. The later may be the case here - as ILS landings can NOT be successfull with the autopilot in heading mode.
Any discrepancy in magnetic heading displayed in X-plane vs any offical charts also depends on the magnetic variation model used in the simulator - which may differ by a (very few, usually just a few 10th) degrees for any given place in the world. So if the PFD display rounds that heading to 126, which charts round it to 125 - that can be caused by miniscule differences, even the annual change in deviation (which is NOT modelled in X-plane) can cause such discrepancies in just 2-3 years. The ILS heading in the scenery aligns with the runway down to one or two hundredth of a degree - so that as dead on as it gets.
Michael Minnhaar February 20, 2019 8:06 PM
P.S. If a pilot does autoland on a CAT-I ILS and does not go around or sidestep to the runway upon reaching decision height - that is always pilot error ... so lets call it a very good real-world training setup until the navaid is fine-tuned.
Robin Peel March 6, 2019 1:47 AM
Thanks! The update to MMUN ILS 12L will be included in the next release of X-Plane that includes updated ILS data. It seemed as if all the ILS data had been shifted a few yards to the north east. - Robin
Im sorry but what happened to the most recently XP11 version?! It got erased!? (2020 one) Please, could you re-upload it or make one again??