Northstar Aerospace (USA) Inc., a maker of aircraft gear and transmission assemblies, filed for bankruptcy protection to facilitate a sale, Bloomberg News reported yesterday. The Belford Park, Ill.-based company listed assets of as much as $50,000 and debt of as much as $100 million in chapter 11 documents filed yesterday. Northstar Aerospace (Canada) Inc. and certain of its Canadian subsidiaries are applying today for an initial order from the Ontario Superior Court of Justice (Commercial Division) under the Companies’ Creditors Arrangement Act, according to a statement. The company in February announced it had entered into a forbearance agreement with lenders under which the creditors won’t take action until Feb. 17. The case is In re Northstar Aerospace (USA) Inc., 12-11817, U.S. Bankruptcy Court, District of Delaware (Wilmington).