Thank you to whomever sent the legal document. That pretty well spells out the FAA's stance.
You're welcome.
I still don't understand it. I can fly people I know to the island all day long and split the operating costs with them without an issue,
Not quite. You can fly them to the island with you when you go there for your own reasons other than to take them, and fly them back, but if you fly back and forth "all day" carrying friends, you're violating the "common purpose" criterion which is not explicitly stated in the regulations. Here's another interpretation taking about that issue, and it just happens to cover flying friends to an island:
http://www.faa.gov/about/office_org...009/bobertz - (2009) legal interpretation.pdf
but if I want to treat 2 people to a charitable lunch and absorb the costs of flying them to the island in my 172 somehow that's wrong. Completely incomprehensible.
Perhaps not so incomprehensible if you understand the background. The FAA is absolutely adamant about having higher standards when folks are paying to be flown somewhere than when they're just hitching a ride with a friend who's going there anyway. That's a major part of their "levels of safety" concept for regulating flight operations. The highest level of safety is applied to "common carriage" operations such as the airlines, a lower level of safety is applied to non-common carriage operations such as charter flights, and the lowest level is applied to pilots flying by themselves (e.g., Student Pilots flying solo).
With these charity flights, someone is paying money to be flown somewhere, and has little idea about who's doing the flying or the plane in which they'll be flown. The FAA views that rather differently than when you're taking friends flying, since the FAA figures your friends know you well enough to decide whether they want to get in a plane with you. In the charity case, they want to provide more assurance of safety to the person paying for the flight but without going through the procedures for certifying a commercial air taxi operator, hence, the strict limits on such flights.
I suppose I should just write a check to the organization equivalent to the cost of av-gas and the meals and call it a day. Doesn't provide anything for an auction but the ultimate point is to raise funds.
You can do what you want, but please try to understand the reasons for the FAA's stance on these flights. As Dean pointed out you can either donate a couple of seats on the air taxi operator's flight out along with the lunch, or instead of donating the lunch, you could donate a sightseeing ride within 25 miles of the airport of departure -- lots of folks (including me) have been doing that for many years, and the riders always seem to enjoy it.
