Orders to U.S. factories for big-ticket manufactured goods fell 1.6% in February, the biggest drop in four months, reflecting a plunge in the volatile commercial aircraft category. Demand in a key sector used to track business investment decisions also declined in February.

The Commerce Department said Tuesday that the February decline came after a small 0.1% rise January and was the weakest showing since a 4.3% fall in October. Orders in a category that serves as a proxy for business investment plans edged down 0.1% in February after a 0.9% advance in January.

The manufacturing sector has been strained for the past few months, reflecting a global economic slowdown and rising trade tensions which have hurt U.S. exports. But there have been more hopeful signs recently.