U.S. factories saw slightly fewer orders for big-ticket manufactured goods in August, with a decline in aircraft orders accounting for the modest slip.

The Commerce Department says that orders for durable goods were nearly flat in August, with an $85 million fall from July to $226.9 billion. The result mostly stemmed from a steep 21.9 percent drop in the volatile category of commercial aircraft.

Total orders have slipped 0.6 percent so far this year to $1.8 trillion. Still, a critical category that reflects business investment — and excludes aircraft — advanced 0.6 percent for the third straight monthly gain.

American manufacturers have seen demand weaken this year, a drag for the overall economy. The strong dollar has hurt exports while lower energy prices have reduced orders for equipment and pipelines.