U.S. and European Union officials are making last-ditch efforts to negotiate a settlement to their long-running dispute over hush kits bringing Stage 2 aircraft into compliance with current Stage 3 noise limits. Both sides want the deeply divisive matter resolved at the September 25 meeting in Montreal of the International Civil Aviation Organization assembly. The meeting is expected to confirm Stage 4 noise limits that would take effect for new aircraft starting in 2006, requiring them to be 10 dB quieter than existing Stage 3 requirements.