Ad. 6) Make sure the flight vibrations are physically correct and happen on the real aircraft.
Why? I admit this is a bit too nerdy for most
but as I mentioned in the LL feedback post I find the existing hover vibration/wobbling artificial and distracting and I cannot see it reflected in any cockpit view videos. Take this random CAT-A takeoff on Youtube here:
Once in a hover the 135 seems quite steady to me. My point at least: there is no up/down bumping vibration. Of course if you are sitting in it you will feel -some- vibrations. That is natural and difficult to prevent.
My issue is: there is no “bouncy” up/down vibration on the real machine like in the MSFS 2024 ND EC135 model and analyzing a clip I recorded out of the sim the period of the oscillation as seen on the edge of the moving sunscreen of the instrument cluster versus the outside seems to be around 0,08sec. The inverse of that is the Hertz count, so 12,5Hz. To my knowledge the slowest shaft is the main rotor shaft. Physically viable it -could- vibrate in 12,5Hz, as this frequency is at least somewhat in the realm of the normal operating range (opposed to the turbines and the whole drivetrain, which has way higher fundamentals for each stage and rotational body) -but it doesn’t make sense to me. Does it to someone here?
Here is my reasoning: A rotational frequency of 12,5Hz would be a rotational speed of 750RPM (12,5*60). That is way too high for the rotor. It should rotate at around 395RPM in a hover. My video analysis of the vibration period lacks precision of course, it could in reality very well have been only 0,0759sec and thus 13,16Hz. That would equal 790RPM → twice the speed of the rotor. Or in noise and vibration terms: 2nd order vibrations.
-But- the EC135 has four blades! So this vibration can neither be in rotational speed or 1st order, which in itself would be a sign for an unbalanced rotor (that we don’t want!), nor can it be irregularities in the rotor blades, because there are 4 blades and thus we’d have to expect 4th order vibrations. So either it’s only 6,85Hz or 26,33Hz. An isolated 2nd order aka 1st harmonic doesn’t make any sense to me. Neither does the perceived vibration shape (up/down) that made me analyze this.
I also noticed this wobble vibration on the H125 -if- you play the career mode and do a hoist mission. If you pick up the load the H125 starts to shake as described, -also- at about the same period, hence same frequency. Although the main rotor also spins around the same speed as the EC135, with the H125 it is even more of a mystery for me, because it is a 3 bladed machine.
Another example is the Skycrane also during lifting missions (6 blades). But I didn’t mind to check the frequency.
It’s a minor thing, yes, but I wonder if there is any basis to it I overlooked or if my reasoning is correct and it’s just an overlay effect where some programmer asked the other “People might say our helicopters don’t shake much. We should just add a steady shake… what frequency should it be?” and another programmer went “I dunno… 12Hz or something??”.
For my taste it is distracting in any case, because it moves the whole cockpit relative to the camera. Just statically. It is not an isolated vibration like on a RL or sim Robinson where the compass shakes a little. Or the DCS Huey, where the instrument console shakes when reaching ETL. Like in the joke above, to me it comes across like an attempt to add “a little action”.