Overall demand for U.S. manufactured goods fell in January, but orders excluding transportation rose unexpectedly, as did a gauge of business spending plans, the government reported Thursday. The US Commerce Department said orders for durable goods—expensive manufactured items expected to last at least three years—fell 1 percent last month. Much of the decline was driven by a 20.2 percent plunge in demand for commercial aircraft, a volatile category. Orders for all transportation goods fell 5.6 percent. Excluding transportation, durable-goods orders rose 1.1 percent, the biggest increase since May, after falling 1.9 percent in December. Orders increased for computers and electronic products, fabricated metal products, and defense capital goods. But orders fell for machinery, primary metals, electrical equipment, appliances, and transportation equipment. The transportation category fell for the second consecutive month as Boeing aircraft orders plunged to 38 last month from 319 airplanes in December, and demand for automobiles declined. The closely watched core capital goods category—considered a measure of business spending plans—rose 1.7 percent in January after declining 1.8 percent the previous month, indicating that companies might be expecting more business during the spring. Despite Thursday's mixed report on durable goods, other data including industrial production and regional factory surveys have suggested that manufacturing activity has slowed in recent months.