MU-30 CREW ATTEMPTED TO FLY A FALSE GS ON APCH TO HOU.

Narrative

I HAD A FLT TO SUGARLAND; TX; EARLY IN THE MORNING IN DIAMOND JET (MOST ALL OF MY JET TIME IS IN 400A). I HAVE ONLY FLOWN IN THE L SEAT OF THIS AIRPLANE ONCE BEFORE VFR (IFR ONCE R SEAT) AND SINCE I HAD A TRIP POSTED THE NEXT DAY IN THIS ACFT; I ASKED THE ASSIGNED CAPT IF I COULD FLY THE 2 LEGS TO GET USED TO THE EQUIP. IT HAS AN OLDER FLT DIRECTOR. I HAVE USED ONLY ON 1 FLT; AND A GPS I HAD GOTTEN SOME ON-THE-JOB TRAINING ON PREVIOUS FLTS. ON THE WAY THERE; I WORKED THE GPS; FELT I WAS DOING OK WITH THAT. THE WX DROPPED TOO LOW TO DO THE APCH INTO SUGARLAND; TX; SO WE WENT TO HOUSTON HOBBY. THE WX WAS TO BE GOOD FOR THE ALTERNATE; BUT LOOKED LIKE IT MIGHT BE DROPPING. CTR AND APCH WERE BUSY AND WE HAD SEVERAL CHANGES ENRTE AND VECTOR ON APCH. WE DID ALL THE CHKLISTS AND AFTER I REVIEWED THE APCH PLATE; I HANDED IT TO THE PNF AND ASKED HIM TO READ OFF ALL FIXES AND ALTS TO DO THE APCH AS WE CAME TO THEM. HE WAS TRYING TO SET UP THE GPS FOR AN OVERLAY -- (THIS; I THINK; WAS A DISTR) AS WE WERE JUST ABOUT READY FOR THE APCH. WHEN WE WERE CLRED FOR THE APCH; I ASKED THE PNF FOR THE ALT I COULD DSND TO. THE PNF TOLD ME THE ALT; AND STARTED THE APCH. I THEN ASKED THE OTHER PLT IF THE FLT DIRECTOR LOOKED OK TO HIM; BECAUSE I THOUGHT IT WAS VERY SENSITIVE. IT WAS THEN I NOTICED I WAS HIGH ABOVE THE GS. SO; I INCREASED THE DSCNT RATE. THE GS CAME IN AND OUT SEVERAL TIMES; THEN LINED UP AND THINGS LOOKED OK. THEN VERY SHORTLY THE FLT DIRECTOR ALT BAR DID NOT AGREE WITH THE GS. THEN THE GS STARTED HEATING AGAIN; SO I SAID LET'S GO AROUND; SOMETHING IS NOT RIGHT; AND JUST THEN WE BROKE OUT; SAW NO ARPT. THE PNF THEN SAID WE WERE ALSO PAST THE MISSED APCH POINT. I HAD ASKED FOR ALL FIXES AND ALTS. WE HAD ALREADY STARTED THE GAR AND MADE THE NEXT APCH WITH NO PROB. AFTER LNDG; TWR ASKED US TO CALL AND THEN TOLD US WE DID THE DSCNT TO THE FAR END OF THE FIELD; NOT THE APCH END AND WANTED JUST LET US KNOW ANY FURTHER WE COULD HAVE HAD SOME PROBS; BECAUSE OF THE AREA WE WERE GOING TO GET INTO IF WE HADN'T STARTED THE GAR. LOOKING BACK AFTER DOING THE SECOND APCH; I NOW REALIZED WE WERE HIGH AND SAW THE PROBS OF THE INSTS; BUT BEING IN A STRANGE AIRPLANE; I STARTED TO ASK MORE QUESTIONS INSTEAD OF JUST GOING AROUND. ALSO; BY ASKING ABOUT THE FLT DIRECTOR; THE PNF TUNED THE TWR; BUT DID NOT SWITCH OVER (TWR WOULD HAVE ALERTED US?). I THINK THAT BY ASKING QUESTIONS ABOUT THE GPS AND DIFFERENCES IN THE ACFT; I GOT INTO 'ASK -- WAIT -- WATCH' STATE OF THINKING. ASKING INSTEAD OF DOING IT. ALSO; WITH THE WX GETTING LOWER; I THINK WE GOT INTO THAT 'HURRY UP' MODE. I HAD BEEN UP VERY EARLY BEFORE THE FLT; BECAUSE SOME CONSTRUCTION SUPPLIES FELL OVER AND COULD NOT GO BACK TO SLEEP. I WAS VERY SURPRISED THINGS WENT THE WAY THEY DID FOR I HAVE 19000+ HRS; NO ACCIDENTS; INCIDENTS; OR OCCURRENCES ON MY RECORD. THE OTHER PLT; I THINK; HAS HAD 1000 PLUS HRS. SOMETHING GOT OUR ATTN; AND WE STAYED WITH THAT ONLY SLOWING OUR SCAN.