Boeing

The 3,000th Boeing 737, a -400 model, was delivered to Alaska Airlines today. The landmark delivery occurred 30 years after the first 737-100 entered commercial revenue service with Lufthansa on Feb. 10, 1968. With more than 3,900 orders, the 737 is the best-selling commercial jetliner of all time. More than 825 737s are in the air at any given moment, with one taking off every six seconds.