Aircraft are often shared among two or more co-owners. If you’re considering this, make sure you have a written agreement documenting your arrangement. This prevents disagreements later by forcing you to think through and discuss each eventuality. Co-owners normally divide fixed or non-variable expenses based on how much of the aircraft each party owns, regardless of how much each one flies. The agreement must balance locking each owner into a commitment with providing reasonable opportunities to exit. I recommend a three year commitment, after that, the plane is sold unless all of the co-owners want to continue. Exit should be possible before then, but it will be more difficult.