David, you're missing the point. While in flight, they could be stored by the passenger using them. At the end of the flight, the flight attendant can collect them prior to the passengers' leaving the cabin. Once collected, give them to the Rockwell Collins folks (or their designees) for battery recharging, etc. When the next flight is ready for boarding, they can again be handed out, either by flight attendants or gate personnel. I see no need for the bulk of them to be stored in the cabin; perhaps just a few contingency spares for units that fail in service or for impulse renters. Most can be stored at the boarding area or shipped in the cargo compartments if needed elsewhere.
Always tell the truth. Then you'll never have to remember what you said the last time.
