Revolution and Deans both make base loaded whip antennas, the heli guys use them all the time with good results but the ranges to see and fly a heli aren't that far.
However I have seen them showing up on jets at our field lately and those guys swear by them.
http://www.wsdeans.com/products/antenna/piece.html
http://www.ronlund.com/Merchant2/mer...t_Code=RVO1010
http://www.quickuk.co.uk/acatalog/r_index.htm