Kerbal Space Program

KSP 1.1.0.1196 x64 Win
KSP 1.0.5 Win

Confirming that this happens both on 1196 and on 1.0.5. Timing it with the example craft, it occurred about every 30-40 seconds for me. It happens very fast, too fast to see the full deflection when on a good framerate, but the stabilization wobling that follows for a second or so is clearly noticeable. Also, if you enable the aero forces in flight (through Alt-F12, Physics, Aero), the sudden wobble in the arrows will be very clear.

Whatever this is, it also causes a sound, like a small far-away explosion. I kept changing sound settings, I tracked it to the ambience sound: with ambience sound set to 0% it is not audible, but with everything except master and ambience set to 0%, you can still hear this small explosive/venting sound every time the glitch happens.

Also, but this doesn't happen quite as regularly: with some regularity, and the lower the altitude the more often it seems to happen, at the same time as the pitch deflection and the sound, sometimes small isolated exhaust 'puffs' appear from a good way ahead of the craft. As if the engine had shortly teleported ahead a few hundred meters for a split second then back again, and the next second the craft is 'flying by' that spot and the few exhaust particles that were emitted there. I don't know how else to explain this, but pay attention and you will see. When they appear, it's always right after the twitch and the sound. I managed to get a few on screenshots, I include them here.

Also, but this doesn't happen quite as regularly: with some regularity, and the lower the altitude the more often it seems to happen, at the same time as the pitch deflection and the sound, sometimes small isolated exhaust 'puffs' appear from a good way ahead of the craft. As if the engine had shortly teleported ahead a few hundred meters for a split second then back again, and the next second the craft is 'flying by' that spot and the few exhaust particles that were emitted there. I don't know how else to explain this, but pay attention and you will see. When they appear, it's always right after the twitch and the sound. I managed to get a few on screenshots, I include them here.

Amazing catch! I never realized that those little cloud things were related to this! I also never noticed the sound, either. Awesome debugging skillz, swjr_swis. Thx for the added info.

I believe this happens when the "floating origin" is shifted. I created a small addon to test this, if you watch the value of "FloatingOrigin.Offset" you'll see whenever you hear the "tshh" noise the value changes.

Here's the link to the source: https://gist.github.com/mjn33/bc80d38b036923c2c6a4c4fbd6ed427b

Here's the link to a pre-built version of that: https://gist.github.com/mjn33/bc80d38b036923c2c6a4c4fbd6ed427b/raw/0e0f4403cf0f772a03bc6776eb54d4918ca0c3c4/VesselModuleMonitor.zip

This plane exhibits the behavior much more often -- at 18km altitude, mach 2, level flight.

Moving to KSP as still valid