Northwest Airlines has made headlines in recent years for a major jetliner crash, a change in ownership, the convictions of three of its pilots who were flying while intoxicated, and its efforts to eliminate smoking on planes. Here are details of those and other events: -Aug. 16, 1987: Northwest Flight 255 crashed near Detroit Metropolitan Airport, killing 156 people when the MD-80 failed to gain altitude during takeoff and slammed into a highway overpass. The National Transportation Safety Board ruled that the pilots didn't set the plane's wing flaps and slats properly for takeoff and that failure of a cockpit warning device contributed to the crash. -March 23, 1988: Northwest announced that it would ban smoking on all of its continental domestic flights effective April 23, the same day a federal law would take effect banning smoking on all flights of two hours or less. Northwest's policy went beyond the new law's requirements. -Aug. 3, 1989: Los Angeles investor Alfred Checchi signed acquisition papers to complete his group's $3.65 billion buyout of NWA Inc., the parent of Northwest Airlines. -Dec. 28, 1989: Northwest publicized a bomb threat it received for a Dec. 30 flight from Paris to Detroit. More than 100 people canceled their reservations for the flight; 28 passengers and 14 crew members made the trip. -Jan. 4, 1990: An engine fell off a three-engine Northwest plane flying from Miami to Minneapolis; the Boeing 727 landed safely in Tampa, Fla. Federal officials said improper maintenance was involved and proposed a $200,000 fine. -March 8, 1990: Three Northwest pilots flying a Boeing 727 from Fargo, N.D., were arrested at Minneapolis-St. Paul International Airport after authorities were alerted that the pilots had been drinking heavily the night before. The three became the first commercial pilots to be convicted for flying a jetliner while intoxicated. Their sentences ranged from one year to 16 months. -May 28, 1990: A Northwest pilot on his way to work was charged with driving under the influence of alcohol. He later pleaded guilty to a lesser charge and was fined $627. The pilot is appealing Northwest's decision to fire him for violating company rules against drinking within 12 hours of a scheduled flight. -Sept. 11, 1990: A Northwest captain's pilot's license was suspended after a hearing in which authorities said he buzzed a snowmobile race in one private plane and crash-landed another because of a fuel problem. -Sept. 20, 1990: Airbus Industrie said Northwest got a $500 million loan from Airbus and General Electric Co. The loan coincided with an order for 75 Airbus planes valued at $4.6 billion. Later, a spokeswoman for U.S. Trade Representative Carla Hills said Hills believed the loan could be an unfair inducement to get Northwest to buy the jets. Representatives of Airbus, a four-nation consortium, denied any unfairness. -Oct. 16, 1990: Checchi said layoffs and a reduced flight schedule were imminent since machinists rejected a temporary wage cut. Northwest announced it was implementing a third major fare increase in as many months due to higher jet fuel prices brought on by Iraq's Aug. 2 invasion of Kuwait. -Oct. 17, 1990: Northwest said ground workers in Atlanta filled the hydraulic systems of two DC-9 jets with a mixture of hand soap and hydraulic fluid. The airline called it a mistake, not sabotage. Fifty flights were canceled around the country and 12 DC-9s were grounded for inspections. -Nov. 12, 1990: Northwest said higher fuels costs associated with the Mideast crisis caused a 47 percent drop in its third-quarter earnings and will result in a fourth-quarter loss. -Nov. 16, 1990: The Saint Paul Pioneer Press reported that Checchi was exploring a buyout of Eastern Airlines using up to $150 million in pension funds of Eastern's union pilots. -Nov. 17, 1990: The Star Tribune of Minneapolis reported that the Federal Aviation Administration had ordered Northwest to examine 11 planes for possible safety defects. The FAA warned that an instrument critical to controlling the plane has jammed at least six times on A320s operated by foreign carriers and in test flights, the Star Tribune reported. -Dec. 3, 1990: Two Northwest jetliners collide on the ground at Detroit Metropolitan Airport, killing eight people.