Valujet's recycled DC-9s are among the oldest in the skies, averaging over 26 years old, compared to 15 years for all domestic airlines, and less than 12 for American, Delta and United. A quarter-century old plane can be perfectly airworthy, if maintained properly. But Valujet contracts out most of its maintenance. The DC-9 that crashed had made seven forced landings in the last two years, due to a variety of malfunctions. The Wall Street Journal reported that during 1995 alone, Valujet experienced at least 66 aborted takeoffs and unscheduled landings, and had four times the number of flight disruptions as TWA, with about the same sized fleet.
New planes are expensive.
The more the airlines undergo cutthroat downsizing, the more they try to squeeze out of aging aircraft. In 1989, Northwest's average plane was 14.1 years old. Today it is 19.1 years old, sugesting that Northwest is replacing few aging planes. In theory, deregulation was supposed to apply to fares and routes, however safety was to stay regulated. Anybody could enter the airline business, but the competence of pilots and the rigor of aircraft maintence would all stay tightly supervised by government.