The DC-9 has been designed and built to be one of the safest in its category.
Proper maintenance gives it an indefinite life.
Its very reliable JT8 engines are derivatives of the JT series family of engines from Pratt and Whitney that powers the F-Series fighter jets. The DC-9 has proven to be so widely accepted that more than 55 airlines worldwide operate a total of 869 DC9s today. Of these, more than 591 are of the series-30 version, and half of this figure is being used by major U.S. airlines for their domestic operations. In September 1998, the Air Transportation Office concluded its airworthiness audit of all Cebu Pacific aircraft and the company passed with flying colors. Cebu Pacific was the only local airline to do so.