Air carrier crew reported receiving GPWS terrain warning during vectors to ILS runway 27 [into] geg....

Narrative:

When briefing the ILS 21 in geg I referenced terrain to the east and northeast of the airport. We both looked over our approach plates and the low chart to get more information about the terrain. I hadn't flown into geg in a few years and the captain flew there a couple weeks ago for the first time in many years.at around 20 miles from the airport we were in and out of the clouds on a heading of 270 which had us heading toward the FAF for the ILS 21. We were also given a descent to 6;500 feet. The autopilot was on and we were in an idle descent. Just below 7;000 feet the GPWS gave us a 'terrain' warning. I immediately executed the terrain avoidance maneuver by advancing the thrust levers to toga; disengaging the ap and auto throttle and inputting full aft stick. I had briefed an MSA of 7;100 feet so I leveled off around 8;200 feet and reengaged the autopilot and auto thrust. The captain told the controller what we were doing and she didn't understand. Eventually she said her supervisor mentioned that a few airplanes had also experienced terrain warnings. We were now clear of the clouds and continued to an uneventful visual approach and landing.

Original NASA ASRS Text

Title: Air Carrier crew reported receiving GPWS terrain warning during vectors to ILS runway 27 [into] GEG. Crew performed escape maneuver. Altitude cleared to was below the Minimum Sector Altitude for that sector.

Narrative: When briefing the ILS 21 in GEG I referenced terrain to the east and northeast of the airport. We both looked over our approach plates and the low chart to get more information about the terrain. I hadn't flown into GEG in a few years and the Captain flew there a couple weeks ago for the first time in many years.At around 20 miles from the airport we were in and out of the clouds on a heading of 270 which had us heading toward the FAF for the ILS 21. We were also given a descent to 6;500 feet. The autopilot was on and we were in an idle descent. Just below 7;000 feet the GPWS gave us a 'terrain' warning. I immediately executed the terrain avoidance maneuver by advancing the thrust levers to TOGA; disengaging the AP and Auto Throttle and inputting full aft stick. I had briefed an MSA of 7;100 feet so I leveled off around 8;200 feet and reengaged the autopilot and auto thrust. The Captain told the controller what we were doing and she didn't understand. Eventually she said her supervisor mentioned that a few airplanes had also experienced terrain warnings. We were now clear of the clouds and continued to an uneventful visual approach and landing.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1334581
Time
Date	201602
Local Time Of Day	0601-1200
Place
Locale Reference	GEG.TRACON
State Reference	WA
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	Large Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	Direct
Flight Plan	IFR
Person 1
Function	Pilot Flying First Officer
Experience	Flight Crew Last 90 Days 20 Flight Crew Total 3408.5 Flight Crew Type 1081.1
Events
Anomaly	ATC Issue All Types Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Inflight Event / Encounter CFTT / CFIT

Air carrier crew reported receiving GPWS terrain warning during vectors to ILS runway 27 [into] geg. Crew performed escape maneuver. Altitude cleared to was below the minimum sector altitude for that sector.