GEAR UP LNDG DURING CHK FLT.

Narrative

WE WERE ON A CHK RIDE. AT ABOUT 2.5 HRS INTO THE FLT I REDUCED PWR TO IDLE TO SIMULATE AN ENG FAILURE AT 3000 FT MSL. WITH PWR REDUCED THE GEAR UP WARNING HORN SOUNDED; AND CONTINUED TO SOUND WHILE THE PF WENT THROUGH EMER PROCS AND NOW STARTED TO SET UP FOR THE APCH AT FIT. I PURPOSELY PICKED THAT LOCATION SO THAT THE PLT COULD TAKE THE AIRPLANE ALL THE WAY TO THE GND WITHOUT PWR. IT SHOULD BE NOTED HERE THAT THE GEAR HORN HAD BEEN SOUNDING ON SEVERAL OCCASIONS FOR LONG PERIODS OF TIME DURING OTHER MANEUVERS CALLED FOR ON THIS CHK RIDE. THE PLT DID ALL THE ITEMS CALLED FOR ON THE EMER LNDG CHKLIST; BUT ANNOUNCED THAT HE WOULD HOLD THE GEAR AND FLAPS UNTIL THE LNDG WAS ASSURED. THE GEAR UP LNDG HORN CONTINUED TO BLARE ON OUR DSCNT FROM 3000 FT. SINCE THIS PLT HAD ALREADY MADE SEVERAL BAD LNDGS (BAD ENOUGH TO REQUIRE ASSISTANCE FROM ME); MY FOCUS WENT TO AIRSPD AND LOOKING OUTSIDE THE ACFT AS WE TURNED FINAL. I DID NOT NOTICE THAT THE PLT DID NOT LOWER THE GEAR; ALTHOUGH HE HAD LOWERED FLAPS. RESULT; LNDG GEAR UP LNDG. CONTRIBUTING FACTORS; I THINK; WAS THE POOR LNDG PERFORMANCE OF THE PLT FORCING ME TO GIVE MORE ATTN TO WHAT WAS HAPPENING OUTSIDE THE ACFT; THAN I NORMALLY WOULD; AND THE FACT THAT I HAD BECOME SO ACCUSTOMED TO HEARING THE GEAR UP WARNING HORN ON THIS FLT FOR LONG PERIODS; THAT I MENTALLY TUNED IT OUT.