I've never taken my Powertap wheel with me when traveling with the Ritchey Breakaway because of the bulge in the hub.
When packing with the Ritchey-recommended method (see Oleg's blog post), in which the rear wheel goes in first with the cassette in the bulge in the case, the front wheel goes in immediately after, each hub fitting in gaps of the spokes of the opposite wheel.
Wheels go first in Ritchey packing method. Note hubs extend between spokes. (Oleg's Cycling Adventures)
The Powertap wheel, however, has a bulbous extension on the non-drive side of the hub which prevents them from extending between gaps in the spokes. Without that, the stack height of the wheels is too large. So for years I would just do without the Powertap when traveling.
But then I saw Oleg's post on packing the Ritchey using the S&S case method. I was skeptical at first, but sure enough, it all fit without problem. I'm spatially challenged, so needed check, double check, and triple check to make sure the orientation of each piece is correct. But while it took me considerably longer than Oleg's 12 minutes to pack my bike, it worked.
packed, S&S method
The key with the Ritchey case is to don't leave the case lying on its side when packing, but lift it up to allow the sides to extend slightly beyond the boundary of the hard sides. Then it will zip shut.
One piece of advice I picked up off BikeForums is to carry water bottles in my carry-on bag instead of in the case. Apparently the bottles may be a magnet for TSA inspection. I've had TSA inspect my Bike Friday way back, several times, but I've had better luck with the Ritchey. In any case, you absolutely don't want that to occur, especially with the Ritchey, because it's a puzzle getting it back together, and small errors can lead to a damaged frame, wheels, or components.
So we'll see how it goes during my upcoming trip.