Here's a interesting tidbit from the Fall 2012 DC9 newsletter the 9 Iron News....
Statistically speaking, Maintenance Control and Line Maintenance appear to be doing a terrific job keeping the DC9 flying as we get closer and closer to the sunset of its life at Delta. I hear very few pilot complaints regarding the number of MEL items on board or issues regarding the quality of repairs. As the most profitable fleet in Delta’s livery, it is important to assure a high level of reliability in the aircraft.
Viva la DC9!!!!!!!!