investigating F-18 HUD deviation

[ginn]

I’d like to report a bug. The HUD of the F/A-18 occasionally shifts (as shown in the image). There was no wind on the server, and I selected a hot start instead of a cold start, so we can rule out user error.

I spawned using a dynamic parking hot start at Kutaisi airbase, with a loadout of two Mk-84s and two Mavericks. Everything looked fine during taxi, but as I accelerated for takeoff, the HUD suddenly shifted to the left. Again, there’s no wind on the server, so external factors shouldn’t be the cause.

When I switched to the F-16, the HUD remained stable during takeoff, which further suggests this issue is specific to the F/A-18. From my experience, this problem only happens when using dynamic parking spots — I don’t recall encountering it with traditional ramp or runway starts.

Additionally, in some single-player missions, the F/A-18 starts hot with the IFA countdown screen stuck. Thecountdown continues, but the page doesn’t disappear as it should.

8770AFD8-916C-4EE2-A0CE-C5B93FD48455.mov

多人联机打靶图20250721练飞,对空对地,编队,空加-20250726-195457.trk

[Tholozor]

If the INS goes to IFA RDR when the knob is placed in IFA, there is no GPS available (or line of sight to the satellites is blocked), and the aircraft is attempting to perform an in-flight alignment.

[ginn]

3小时前，Tholozor说：

If the INS goes to IFA RDR when the knob is placed in IFA, there is no GPS available (or line of sight to the satellites is blocked), and the aircraft is attempting to perform an in-flight alignment.

This I know. You can see in the video that in such situations, after dynamic placeholder hot alignment is completed and the INS is also aligned, the HUD still shows deviation during takeoff.

[ginn]

[ginn]

new trk

多人联机打靶图20250721练飞,对空对地,编队,空加-20250727-010250.trk

[NineLine]

I'm looking into it, seems to be something going on, thanks!

[ginn]

11小时前，NineLine说：

I'm looking into it, seems to be something going on, thanks!

This issue has been troubling me for a long time—I hope it gets fixed as soon as possible

[[ED]Ben]

Hi - i have looked at this, and I can replicate the shift only in the mission you attached. Are you able to replicate in a simple misison? 

[ginn]

20小时前，[ED]Ben说：

Hi - i have looked at this, and I can replicate the shift only in the mission you attached. Are you able to replicate in a simple misison? 

In fact, I was able to reproduce this issue on other multiplayer servers as well. However, the HUD offset doesn’t always occur to the same degree — sometimes it’s just a slight deviation. There was still no crosswind in the mission. During landing, I tried to place the FPM (Flight Path Marker) on the runway centerline, but the actual flight path of the aircraft was offset from the centerline.

[ginn]

20小时前，[ED]Ben说：

Hi - i have looked at this, and I can replicate the shift only in the mission you attached. Are you able to replicate in a simple misison? 

The cold start training mission for the F/A-18 also occasionally shows slight HUD offset. I’ll upload a track file later. This seems to be a probabilistic issue — it doesn’t happen every time, but it’s relatively easy to reproduce.

For now, my workaround is to re-align the INS every time I hot start, and I avoid switching to IFA while still on the ground, as I suspect it may be related to the issue.

[ginn]

22小时前，[ED]Ben说：

Hi - i have looked at this, and I can replicate the shift only in the mission you attached. Are you able to replicate in a simple misison? 

This is the HUD after completing the cold start training mission, with the INS knob set to NAV mode and not switched to IFA. It appears to be normal, with no visible offset.

TEAT1.trk

[ginn]

22小时前，[ED]Ben说：

Hi - i have looked at this, and I can replicate the shift only in the mission you attached. Are you able to replicate in a simple misison? 

This time, after completing the cold start and switching to IFA mode while still on the ground, the HUD did not shift. I’m not sure if this is due to a recent DCS update.

Later, I tried switching the INS knob to IFA immediately after engine start and began flying while it was still aligning. As expected, the HUD showed a slight rightward offset. I’m not sure if my procedure was correct, but the result was the same as the HUD offset I experienced during hot starts on multiplayer servers.

(Note): The video showing the HUD shifting to the right is from the cold start mission, while the other one is from a multiplayer server mission.

PVP PVE 黑海综合训练地图 v33.1-20250730-162024.trk