We have a DA-40 TDI that's fully IFR equipped. It's really a 2.5-person only plane with full tanks (and we don't even have long range tanks). Three average adults with full tanks will push it over its MTOM.
And our Center of Gravity problem is the same. Two adults up front brings you forward of the limits. We calculated how much counterweight was needed and have made a sealed and marked bucket of sand, 17 kgs exact, that goes into the aftmost baggage area when flying with two adults up front only. That brings things within limits exactly.
Doing a few mock W&B calculations, and showing the bucket of sand is part of our mandatory checkout procedure.
The other way that you can bring the aircraft out of its limits is by initiating a fuel transfer and then forgetting to stop it in time. The difference between left and right may be no greater than 8 USG (I believe - it's been a while) and I can testify that quite some sideways force on the stick is required, particularly during landing, if you exceed that difference.
Last edited by BackPacker; 15th Jul 2009 at 07:34.