Ive only toyed with the idea of a plane for myself and have tried to justify it.
I've been through the same exercise (like most everybody here) and the conclusion is simple: I (we) can not and never will be able to justify (on paper) owning a plane. It will never work out - unless you use that new math.
That being said, I can only add one thing: Who cares?
Here endith the lesson.
Jim
