The retirement of these 30 DC-9's should not adversely impact the current schedule. Included in the 30 are about 6-8 aircraft that are currently in storage, thus they will now be retired.
NW is taking a delivery of a few A319's/A320's this year which will help offset the lost of some DC-9's.
Increased utilization of the current fleet will make up the bulk of the difference of the retired DC-9's. The DC-9 fleet utilization has been rather low with several aircraft being used as spares. Avro utilization will also be increased. The 30 DC-9's are not all being retired at once; they will be retired as they come due for heavy maintenance. Most of this will occur after the busy summer travel season, which coincides with annual reduction in capacity going into the fall/winter months.