Israeli plans to buy 50 US-built F-16 C 50 multi-role fighters have run into a snag. The Israelis want to use four of their own avionic sub-systems in the aircraft, but to do this they will need to use the US-designed Joint Data and Information Transfer System. The US has refused to provide this system to the Israelis unless they use the four US-built sub-systems that are attached to it in aircraft used by the US Air Force. The US has told the Israelis that their alternative is to develop their own version of JDITS, something that would take years. The Israelis had thought that the US was stonewalling on the system as part of forcing the cancellation of the Phalcon radar plane sale to China, but after this was canceled the US still refused to sell the JDITS. Israeli analysts are now convinced that the US is trying to block the Israelis from selling their sub-systems to other F-16 users in competition with factory-official US sub-systems.--Stephen V Cole