Request a copy of the co-op's by-laws and rules. Read them thoroughly and check to see what is included in the share cost. Check how many hours per month you are allotted with the co-op, and what the monthly hanger and maintenance fees are.
Read all of the aircraft's maintenance logs. If unsure of how to read them for accurate information in the condition of the aircraft, hire an aircraft mechanic to go over the logs and the aircraft. Things to look for are ADs, or Airworthiness Directives. ADs placed on the aircraft are done so through the FAA inspections and may add additional cost to monthly maintenance.
Meet each member of the plane share co-op. Personalities are important when purchasing a share in an aircraft. If you clash with members, the co-op may not be a good idea. Check to see what the attitudes of the members are regarding aircraft safety, flying and risk taking. Shy away from co-ops with "cowboy" pilots. Stay safe.
Ask what the re-sell terms are. If you should opt to sell your co-op share in the future what are the rules governing this. If too restrictive, consider a different club.
Inspect the aircraft and hanger. Talk with the actual aircraft mechanic and pay to test fly the aircraft. Once you feel the decision is the proper decision for you and your flying, have your lawyer go over all documents during the purchase.
