BEECH 1900 ACFT. MISCOM ON ALTS ASSOCIATED WITH APCH. FLC THOUGHT THEY WERE CLRED TO 3000 FT; BUT ATC HAD ONLY CLRED THEM TO 4000 FT. CTLR RECLRED THEM TO 3000 FT; BUT AFTER LNDG INSTRUCTED FLC ON PROCS. APCH PLATE NOTES SPECIFY CORRECT ALTS FOR PARALLEL APCHS.

Narrative

WE WERE APCHING FOR LNDG ON RWY 28R AT PITTSBURGH INTL. THERE IS CONSTRUCTION ON RWY 28R AND AS A RESULT THE GS IS OTS AND ALL APCHS REVERT TO LOC ONLY APCH MINIMUMS WITH STEP-DOWN FIXES. WE WERE GIVEN A HDG TO INTERCEPT THE LOC (CURRENTLY AT 5000 FT MSL) AND AN APCH CLRNC WHICH WE UNDERSTOOD AS 'CLRED FOR THE APCH AT OR ABOVE 3000 FT.' AS WE BEGAN OUR DSCNT TO 3000 FT WE WERE ASKED WHAT OUR ALT WAS. WE RESPONDED BY GIVING OUR CURRENT ALT OF 4000 FT. WE WERE THEN INSTRUCTED TO CONTINUE DOWN TO 3000 FT. UPON LNDG WE WERE INSTRUCTED TO CALL ATC. UPON DISCUSSING THE SIT WITH ATC WE LEARNED THAT DUE TO THE SIMULTANEOUS APCHS ON RWY 28L AND RWY 28R; ONE SIDE IS CLRED AT 3000 FT WHILE THE OTHER IS CLRED AT 5000 FT TO BEGIN THE APCH. ON THE APCH PLATE IT HAS A NOTE THAT SAYS YOU MAY DSND TO 3000 FT AT CTLR'S REQUEST. WE WERE APPARENTLY CLRED FOR THE APCH AT 5000 FT; AND NOT 3000 FT LIKE WE UNDERSTOOD IT TO BE. CONTRIBUTING FACTORS TO THIS MISUNDERSTANDING OF ALT CLRNC WERE: THE NOTE ON THE PLATE STATING A CLRNC TO 3000 FT IF CLRED BY ATC AND OUR MISUNDERSTANDING OF OUR ACTUAL CLRNC. THE SIT WAS DISCOVERED BY ATC AND CORRECTED BY THEM CLRING US TO 3000 FT. THERE WAS NO TFC ON RWY 28L AND NO CONFLICT. IN THE FUTURE; I WILL BE SURE TO QUERY ATC ANY TIME I AM NOT 100 PERCENT SURE OF OUR CLRNC. ATC WAS QUITE HELPFUL IN EXPLAINING THE SIT TO MYSELF.