The traffic decline at the world's airlines is impacting Boeing ( BA), which has a net total of minus 10 orders this year. The aircraft manufacturer took just four orders in February and 18 in January, according to Boeing's Web site. And 32 orders for 787 jets have been canceled this year. The only U.S. carriers that have placed orders this year are Alaska ( ALK), which has ordered one 737, and Southwest ( LUV), which has ordered five, Boeing said. The bulk of Boeing's orders are from Ryanair, which has ordered 13 737s. However, undisclosed carriers have canceled orders for 32 Boeing 787s. Cancellations are considered likely to increase, given the global economic slowdown, and Delta ( symbol) could potentially take fewer aircraft than planned. When it acquired Northwest, Delta inherited an order for 18 of the 787s. A Delta spokeswoman noted the carrier has not canceled its order. However, in a recent filing with the Securities and Exchange Commission, Delta said it had dropped the aircraft from its 10-K report on new orders. "We have excluded from (the report) our order for 18 B-787-8 aircraft," Delta said, because Boeing has said "it will be unable to meet the contractual delivery schedule for these aircraft." Delta said it is "in discussions with Boeing regarding this situation." In January, Boeing said the backlog at Boeing Commercial Airplanes is $279 billion. The company intends to reduce its workforce this year by 6% or 10,000 positions.