Negotiators from the United States and Japan started the fourth official civil aviation talks Oct. 20 in Washington but found a considerable gap between their positions over a four-year interim accord.On the first day of the talks, the negotiators remained at odds over the expansion of aviation rights for so-called nonincumbent carriers, which face restrictions under the current bilateral aviation treaty, a Transport Ministry official said. The U.S. demanded more than 100 flights per week for those carriers, while Japan wanted 70 flights a week, according to the official.Because there was no progress on this matter, they discussed the possibility of asking for a judgment at a political level if the current vice ministerial talks become bogged down, the official said. Although the negotiators hope to reach an accord by Oct. 24, the official suggested two scenarios: either negotiations continuing into next week or the political judgment being sought.On the second day, negotiators will discuss the issue of beyond rights, which allow airlines to fly to third countries via Japan or the U.S., and the "safety net" issue. The safety net provides aviation rights as demanded by the U.S. as a guarantee when the interim accord under current discussions expires and if the following accord is not duly reached.Along with the negotiations, the two governments are looking into such matters as code sharing and charter services at the working group level.