20060219003559I

(-23) On February 19, 2006, skywest airlines flight #20A (SKW20A) departed the Salt Lake City International Airport enroute to grand junction, Colorado. After takeoff SKW20A was cleared to climb to flight level 210. During climb out the crew received a "l pack hi press" caution message and consulted the quick reference handbook (qrh). The qrh required them to reduce engine power on the affected side of the caution message resulting in a reduced rate of climb. ATC issued an expedited climb due to terrain. SKW20A advised unable to expedite climb due to pac failure. ATC issued climb to 11,000 MSL and an immediate left turn away from terrain. Due to reduced climb performance as a result of reduced power in accordance with the qrh, SKW20A entered 10,000 foot minimum vectoring altitude (mva) at 9600 fet and a 10,400 foot mva at 9,900 feet while climbing to 11,000 feet. Weather at the time of the incident was day VFR. SKY20A was dispatched with the right air conditioning pac inoperative and differed per the minimum equipment list (MEL). During takeoff and initial climb conditioned air was being supplied to the aircraft cabin by the auxiliary power unit (APU). After takeoff the conditionedair was switched from the APU supply to engines supply. When condition air was switched from APU to engines the crew failed to follow the procedure listed in the MEL by closing the supply from the APU and allowing pac pressure to reduce to less then 5 PSI before opening the supply from the engines. As a result the crew received a "l pack hi press" caution message requiring them to follow the qhr procedures of reducing engine power. This reduction in engine power prevented the aircraft from climbing at a rate sufficient to meet airspace and terrain restriction. SKW20A notified ATC of the pac problem and informed them they were not able to expedite their climb, as requested by ATC, prior to penetrating airspace which was below the mva.