[Derda508]

Many, many years ago an uncle of mine allowed me to join him for a flight in an open bi-plane (Bücker Jungmann) he restorated himself for aerobatics.
As Alpha stated: the vibrations and the noise were overwhelming, even befpre take off. Trying to simulate the sound eralistically would bring you into real trouble with your neighbours. It got even louder, when the air was rushing by. I found the headsets for communication pretty useless.
The feel of gravity and acceleration is equally strong. When doing rolls or loopings a beginner has huge problems to trust into his seat belts and not to press both feet on the pedals out of sheer terror (which would not be a good idea). Basic manouevres, like gentle turns almost everybody can master without instructions. It took a while for me to understand the crackling sound of the headset, but at some time my uncle informed me that actually I was flying the plane for about five minutes ...
In a glider noise and gravity are much less radical, but still noticeble. What I remember most is the heat and the blinding of the sun when it wandered through the canopy. Something that I found reflected somehow with the dynamic shadows in CloD, sadly impossible in Il-2.
So I think that at least 50% of the experience are missing.
Luckily, because if they could be implemented most of us would not be allowed to use such a sim for medical reasons.