Frankly, they would have been gone years ago, but for a nearly-bankrupt Northwest realizing that they had 30 years worth of parts for them sitting in the desert, already paid for. They were all a broke NW had that could provide needed F/C service to smaller cities like SBN or ATW. (They had tried Avro-85's/ BAE-146's under Mesaba as replacements, but the they couldn't make them work. (SCOPE'd out at 69 seats max, which made them too expensive to fly with 4 holes.)) A lot of their corp. contracts required F service. That is why they kept the DC9-10's around so long.