CL65 CREW RECEIVES GPWS WARNING ON APCH TO AVP AT 4000 FT.

Narrative

WE WERE ON APCH INTO AVP (SCRANTON; PA). FLT CONDITIONS WERE COMPLETE IMC AND THE ARPT WAS RPTING 800 FT OVCST CEILINGS. WE WERE ON A 040 DEG HDG ON DOWNWIND FOR THE ILS RWY 22 NE OF THE ARPT. THE CAPT WAS PF AND WAS SURE TO GIVE A THOROUGH APCH BRIEF. HE WAS SURE TO POINT OUT THE VERY TALL ANTENNAS (2016 FT AGL) ON THE APCH PLATE. WE COMMENTED TO EACH OTHER THAT WE DIDN'T LIKE BEING SO LOW SO FAR FROM THE IAF (3800 FT MSL). WHILE LEVEL AT 4000 FT MSL APPROX 5 MI NE OF THE ARPT BTWN COSBY AND DUMOR WE RECEIVED A GPWS 'TERRAIN; TERRAIN' CALL AND FLASHER. THE CAPT IMMEDIATELY DISCONNECTED THE AUTOPLT AND BEGAN PITCHING UP WHILE ADVANCING PWR. BEFORE THE ENGS EVEN SPOOLED UP WE RECEIVED A 2ND GPWS CALL. THIS TIME IT WAS 'TERRAIN TERRAIN; CLB CLB' AND FLASHER. I RPTED THE ALTDEV AND REASON IMMEDIATELY TO ATC. THE CALLS CEASED AND WE LEVELED OFF AT 5000 FT MSL. HE TRIED TO DSND US TO 4000 FT AGAIN BUT WE REFUSED UNTIL ESTABLISHED ON THE FINAL APCH COURSE. ONCE ON THE GND WE SPOKE WITH THE TWR CTLR ABOUT THE EVENT. HE ADVISED US THAT 4000 FT WAS A NORMAL DOWNWIND ALT FOR THE ILS RWY 22. I THINK THIS NEEDS TO BE LOOKED AT BECAUSE THERE IS NO REASON TO BE AT 4000 FT ON A 10 MI DOWNWIND WHEN THE INITIAL APCH FIX IS AT 3800 FT MSL.