Boeing 737 JT8D

Hours per fatal accident: 507,500 *
Years built: 1967-1988
Number in service**: 517

The oldest version of Boeing's 737 (JT8D refers to the Pratt & Whitney engine on the plane) is still flown by many carriers in poorer countries, which frequently are hard-pressed to pay for essential maintenance and training. A nearly 30-year-old model of the plane, operated by Itek Air in the former Soviet republic of Kyrgyzstan, crashed near that country's captal, Bishkek, in August 2008, killing 68 people.

* Number of hours flown per fatal accident. The lower the number, the higher the accident risk. Unless noted, the figure shown is the average for the five years ended in 2008.

** At end of 2008