His visit to the plant in the northwestern state of Washington comes days after Beijing announced a deal to purchase 80 Boeing jets valued at around $5 billion.
Mr. Hu arrived in Washington state Tuesday and toured the headquarters of U.S. computer software giant Microsoft with company founder and chairman Bill Gates.
The Chinese president travels to Washington D.C. later Wednesday, and meets Thursday with President Bush at the White House.
Those talks are expected to focus on U.S. demands that China reform its currency, China's human rights record, trade, and the nuclear programs of North Korea and Iran.
Demonstrators gathered outside Mr. Hu's hotel in (the city of) Seattle, protesting his visit and rallying for Tibet, Taiwan independence, and the Falun Gong spiritual movement, a group which Beijing calls an evil cult.Some information for this report was provided by AFP, AP and Reuters.