You bring back great memories of flying with my 90 lb Weimaraner, Rudy, in the 80's. He really enjoyed it and I loved taking him on poker runs and fly-ins(and he was a great chick magnet). Back then no products existed for dogs who flew in private aviation, but numerous products and sellers are available today.

This year's Oshkosh had an exhibitor in one of the hangers with some really innovative stuff. Search for 2013 exhibitors on the Oshkosh site, you'll find it, had "pets" in the company title I believe. Getting ear protection for your dog is a very good and necessary idea(if he'll wear it--might be easier for droopy ears than pointed). There are also unique wearable restraints that attach to seatbelts that are equally necessary.