WASHINGTON, March 24 (Reuters) - New orders for key U.S.-made capital goods unexpectedly fell in February, suggesting some cooling in business spending on equipment after recent strong growth. Orders for non-defense capital goods excluding aircraft, a closely watched proxy for business spending plans, dropped 0.8% last month, the Commerce Department said on Wednesday. These so-called core capital goods orders gained 0.6% in January. Economists polled by Reuters had forecast core capital goods orders rising 0.5% in February. (Reporting by Lucia Mutikani Editing by Chizu Nomiyama)