Originally Posted by
AndyTLe
As long as the pilot is trained on that aircraft type (I don't know if the DCs are different from the MDs or not).
IIRC only the 777s and 747/787s have "fences" for five years from date of the single operating certificate. Only pre-merger pilots can fly those aircraft.
The MD-88 and MD-90s are just stretch variants of the DC-9. From what I understand, a pilot that's rated for one should be rated to fly the others, because they're all DC-9s.