That's discussing the number of 90 seaters allowed to fly at the regional level. For the min fleet number you have to look at a different section of the transition agreement. Like Jim stated, there's a baseline set, then a new one set at 1 yr after escape of BK minus 10%....
B) During the first year following the consummation of the Merger
Agreement, America West and US Airways will each maintain not
less than 80% of the number of aircraft (excluding SJs as defined
in the US Airways agreement as amended by this Letter of
Agreement) listed by month for that airline in Attachment B.
c) For US Airways, the number of minimum aircraft will be established
one year after the consummation of the Merger Agreement at the lesser of 279 total aircraft (excluding SJs), or the number of total aircraft then operated by US Airways (excluding SJs) less ten percent (10%), rounded to the nearest aircraft, with the daily utilization rate measured monthly as the average daily utilization rate for the prior twelve months less ten percent (10%).
d) For America West, the number of minimum aircraft will be established one year after the consummation of the Merger Agreement at the lesser of 140 total aircraft (excluding SJs), or the number of total aircraft then operated by America West (excluding SJs) less ten percent (10%), rounded to the nearest aircraft, with the daily utilization rate measured monthly as the average daily utilization rate for the prior twelve months less ten percent (10%).