Among the more successful post-deregulation U.S. airlines was Piedmont Airlines, who launched service in 1948 as a local service/feeder airline. Piedmont was an early customer of the 737, initially ordering (6) with deliveries beginning in May 1968. In 1984, following 5 profitable years in which annual growth averaged around 30%, with a route network stretching from coast to coast and annual revenue exceeding $1 Billion, Piedmont entered the ranks of 'major U.S. airlines. Also by 1984, Piedmont was the world's largest 737 operator with (63)-200's in their 100 A/C fleet, the airline placed it's first order for the 'mid-generation' 737 when (15)-300's were ordered plus (15) options.The -300 series was 113" longer (compared to -200), with accommodation for up to 149 passengers. Other changes included a 21" increase in wingspan, increased area of the vertical fin at the root and the more efficient CFM56-2/-3 engines mounted in nacelles/pylons of all-new design. On June 4, 1986, Piedmont became the launch customer for the 156-seat 737-400, placing an order for (25) Plus (30) options. Improvements included; 9'6" longer fuselage, uprated CFM656-3B2 engines, tail skid, 2 overwing exits and new Kruger-type flaps outboard of the nacelles. On March 9, 1987 Piedmont and USAir had announced their plan to merge, which received DOT approval on October 29th. Piedmont's 1st 737-401 (N404P) was now registered as N406US and arrived on September 15, 1988. The (14) -401's and the remaining factory delivered -301's were all given an interim Red or Blue stripe NMF designed to easily be revised to the standard USAir color scheme. Sadly, on August 5, 1989, with the final consolidation into USAir, the Piedmont Airlines name would disappear forever............John3 (Thanks to Todd).