The Commerce Department said new orders for manufactured goods in May, up three of the last four months, increased $9.9 billion or 2.1% to $485 billion. This followed a 1.3% April increase. Excluding transportation, new orders increased 0.6%.

Most of the increase in May was due to a big jump in volatile commercial aircraft demand. Still, businesses also ordered more machinery, computers and household appliances.

A category of orders that’s viewed as a proxy for business investment plans — which excludes the volatile areas of transportation and defense — rose 1.5%. That was even stronger than solid gains in the previous two months.

This measure of business investment hadn’t increased for three straight months since the fall of 2011. The consecutive gains suggest U.S. manufacturing could improve in the second half of the year.

To read the Commerce Department report click here.