LR24 FLT CREW FORGETS LANDING GEAR AND GEAR WARNING HORN DOES NOT SOUND. SUCCESSFUL GO AROUND IS INITIATED WHEN SCRAPING NOISES ARE HEARD; AND AN UNEVENTFUL GEAR DOWN LANDING ENSUES.

Narrative

THE FLT TOOK OFF ON A VFR FLT FOLLOWING FLT PLAN TO THE ZZZ ARPT UNEVENTFUL WITH THE FO FLYING (PF). THE FLT WAS CLRED TO THE FINAL ALT OF 3000 FT. THE ATIS WAS REQUESTED BY THE FO AND THE CEILING WERE RPTED TO BE 600 FT OVCST AND IMC CONDITIONS EXISTED AT THE ARPT; THE ACTIVE RWY IN USE WAS RWY XX WITH THE INST APCH BEING THE ILS FOR XX. AT APPROX 10 NM FROM THE ARPT AND WITH A SPD OF ABOUT 190 KTS APCH FLAPS WAS REQUESTED BY THE FO; FLAPS SETTING WAS CONFIRMED. AFTER BEEN CLRED FOR THE ILS APCH TO RWY XX AND WITH THE LOC NEEDLE ALIVE THE STANDARD CALL OF 'FLAPS 20; GEAR DOWN; BEFORE LNDG CHKLIST' WAS INITIATED BY THE FO. AT GS INTERCEPT FULL FLAPS WERE REQUESTED. AT ABOUT THE SAME TIME THE CAPT (PNF) WENT AHEAD AND DID A SIMULATED ENG FAILURE. I IMMEDIATELY TOLD HIM FLAPS 20 AND HE REPLIED SAYING 'THAT IS WHAT I WANT TO HEAR' WHILE GIVING BACK THE ENG. THE GS WAS NOTED TO BE OSCILLATING AT THIS TIME AND WAS RPTED TO THE TWR. THE APCH CONTINUED AND JUST AT THE TOUCHDOWN POINT A GRINDING SOUND WAS HEARD. WE IMMEDIATELY INITIATED MAX TKOF THRUST; REALIZING THAT THE GEAR WERE NOT DOWN WE WENT AROUND AND AFTER DEPLOYING THE GEAR AND DOING THE BEFORE LNDG CHKLIST WE DID A NORMAL LNDG. AFTER LNDG THE CAPT COMMENTED THAT THE GEAR HORN WARNING WAS INOP. THIS WAS CONFIRMED BY BOTH OF US WITH THE CAPT AGREEING THAT HE DID NOT PUT THE GEAR DOWN WHEN ASKED. THIS ACCIDENT WAS DUE TO THE CAPT DEVIATING FROM STANDARD OPERATING PROC BY DOING A SIMULATED ENG FAILURE IN IMC CONDITIONS AND NOT DEPLOYING THE GEAR WHEN ASK TO; HOWEVER I ALSO FORGOT TO CONFIRM THE GEAR WERE DOWN DUE TO MY PREOCCUPATION WITH THE OSCILLATING GS; DAMAGE TO THE FLAPS WERE MINIMAL; AND THERE WAS NO STRUCTURAL DAMAGE.