B727-100 CREW HAD ALTDEV IN ROC CLASS C AIRSPACE.

Narrative

WE WERE FLYING AN EXTENDED R DOWNWIND FOR THE ILS RWY 22 AT ROCHESTER. WE WERE ASSIGNED 2500 FT AND WERE FLYING AT 2500 FT. WE WERE TOLD TO SLOW TO FINAL APCH SPD (WE WERE FLYING AT APPROX 230 KTS). THE CAPT ASKED FOR 'GEAR DOWN;' SO I EXTENDED THE LNDG GEAR 10 MI OUT. WE WERE SUBSEQUENTLY GIVEN A R BASE VECTOR. WE WERE SLOWING RAPIDLY AND I CALLED OUT 'CLR TO 198 DEGS;' AND WE EXTENDED THE FLAPS TO FLAPS 2 DEGS RIGHT AT 200 KTS. IMMEDIATELY AFTER WE WERE GIVEN A FURTHER VECTOR TO THE R AND TOLD TO MAINTAIN 2500 FT UNTIL ESTABLISHED; INTERCEPT THE LOC; AND CLRED FOR THE ILS RWY 22 APCH. I MOVED MY HDG BUG TO OUR VECTORED INTERCEPT HDG THEN LOOKED OUTSIDE FOR TFC AND FOR THE RWY. A FEW SECONDS LATER; I HEARD THE STICK SHAKER GO OFF. I QUICKLY TURNED MY EYES BACK INTO THE COCKPIT AND SAW MY CAPT REACHING FOR THE THROTTLES SO I EXTENDED THE FLAPS TO FLAPS 15 DEGS (REALIZING HE GOT TOO SLOW). THE STICK SHAKER QUICKLY STOPPED AND I LOOKED AT MY INSTS. THE ALTIMETER READ 2100 FT. I ANNOUNCED 'ALT; ALT.' AT THE SAME TIME ATC NOTIFIED US OF OUR ERROR AND TOLD US TO MAINTAIN 2500 FT. WE CLBED BACK UP TO 2500 FT; INTERCEPTED THE LOC AND GS; AND COMPLETED THE APCH WITHOUT FURTHER INCIDENT. I BELIEVE EXTENDING THE GEAR 10 MI OUT WAS UNNECESSARY; THAT THE CAPT'S SITUATIONAL AWARENESS WAS POOR; AND THAT HE WAS NOT 'FLYING' THE AIRPLANE. BASICALLY; THE CAPT MADE AN ERROR AND MAYBE I SHOULD HAVE BEEN MORE ALERT TO HIS AIRSPD MGMNT (SAME FOR THE FE).