Larry,
CIES has not finished development on the RV sensors to my knowledge. They are not completely comfortable with a solution that cannot gauge the first fuel gallons of fuel from full tanks (single float sensor in the wing root, same as Van's system with the SW sender). I have told them that I think the Van's community is willing to accept the non-gaugeable at the top and they should go ahead and start offering the single sensor system. No idea if they are planning to do it or not. They seem to want to offer a dual sensor unit with the second sensor installed on the outboard tank rib. Personally, I would not like the dual sender solution as it would double cost, increase weight, and take what would be a super easy installation into a major PITA. My last conversation with them on the RV topic was at Oshkosh this year. I have offered up my RV6 as a beta test subject!
I am using CIES senders in an FAA STC'd fuel system project for a part 27 rotorcraft and am sold on the technology and the quality of the unit.
