On Friday, January 22, 2016 at 12:19:47 PM UTC-5, kirk.stant wrote:

My gut feeling is that any length long enough to be useful would be pretty draggy!

I figure the wing tip is already very draggy. How much worse could it get? I'm thinking about 12" would work as the tape acts like a signal mirror picking up the sun glint. The wing tip turbulence means it passes through a lot of different angles.