[NEW YORK] The major systems on Boeing's 787 Dreamliner jets are safe and well-designed, but federal regulators need to provide more oversight of the far-flung supply networks that are building these and other planes today, according to a report released on Wednesday.

The study was prepared by experts from the Federal Aviation Administration and Boeing itself after problems with smoke and fire coming from new lithium-ion batteries led to a four-month grounding of the innovative jets last year.

The report was ordered by Michael P Huerta, the head of the FAA, who said on Wednesday that the 787, which relies on new technologies to reduce fuel costs, "meets its intended level of design safety". The joint FAA and Boeing team did not look at the problems with the batteries, which have been redesigned to minimise hazards.