Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 194; Flight Crew Type 595
Confusion; Situational Awareness; Workload
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter CFTT / CFIT
Flight Crew Took Evasive Action; Flight Crew Returned To Clearance; Flight Crew Became Reoriented
Weather; Aircraft; Environment - Non Weather Related
While doing a DME arc to ILS 12 to BZN we were cleared to descend to 11;000 feet. During level flight we received a GPWS 'PULL up' oral warning. I immediately complied with the oral warning and engaged in a GPWS escape maneuver. Once we leveled off at 14;000 feet it became evident that we were clear of terrain. We immediately advised ATC of our GPWS escape maneuver and return to the previously assigned altitude.
A large transport's EGPWS alerted PULL UP on the BZN ILS DME 12 at 11;000 feet. The First Officer took the appropriated action and the alert ceased at 14;000 feet. The terrain beneath the aircraft rose to about 9;400 feet which may have activated the terrain closure feature.