United's maintenance costs continue to fall as the carrier parks older aircraft, the carrier's latest 10Q (.pdf) shows
. In the third quarter, year-over-year maintenance, materials and outside repair costs fell 1.2 percent, or $3 million, to $253 million. For the nine months ended Sept. 30, the costs are down a notable 17.3 percent, or $150 million, to $718 million. By yearend, United will have parked 100 planes this year, including all of its Boeing 737s
and six 747s.