I am trying to think about this logically, think about the heart like a pump and the aorta is the pipe the fluid flows through from the pump, a dialation of the pipe should not affect the function of the pump. Now changes in altitude in a flight may affect the levels of oxigen in your blood, if your body has a need for extra oxigen the heart does try to compensate by pumping harder (high altitude sickness is an extreme example of that) and cause distress in the heart, obstructions would also cause the heart to pump harder (but you are being seeing by s a Cardilogist, so I assume he/she has checked you for possible obstructions). Anxiety may also be a factor, are you stressed during flights? High level anxiety may feel like your heart may explode. Now stress and anxiety may raise your BP and that would have a negative effect on the aneurysm. I just can't think how it can be the other way around (an aneurysm affecting cardiac function during specific moments), but I am not a Dr (I am an engineer by training) maybe there are fisiological factors I am not considering, but your Cardiologist would know those