i have buzzzed a lot of tandems as well as flown around them to with in 5-10 feet( carving) and no one has ever had a problem, passengers love it every tm has said it was the best visuels to see some in front of them and then to just dissapear of into the next tandem up the hill.
Prior, Preparation, Planning, Prevents, Piss,Poor,Peformance Deal with it