81s, two ATR42s and several smaller aircraft, said on Wednesday it had grounded its only remaining operational aircraft, a Czech-built LET 410 turboprop. The MD-82 aircraft that crashed had passed a safety check by Colombian authorities on Monday. But the airline has been penalized before for excessive weight and safety violations. Boeing Co., which took over MD-82 maker McDonnell Douglas in 1997, said the company was dispatching a team of air safety investigators to help find the cause of the crash. The U.S. government also offered to assist. While they went out of production in 1999, the twin-engine MD-80 family has been a workhorse on short-haul flights for the industry for 25 years. MD-80 engines, mounted on the rear of the fuselage, are built by Connecticut-based Pratt & Whitney and have a history of dependability. Pratt is a unit of United Technologies Corp.
