Narrative:

While being vectored for an ILS approach to runway 28R pit, I was given numerous heading, altitude and airspeed changes, which caused a heavier than normal cockpit workload. My VOR/ILS radio was tuned to the ILS. The copilot's VOR/ILS radio was tuned to mmj/VOR for DME and bearing. The #2 DME display on my side started to display #'south with segments missing. I was given clearance to 'turn right to 240 degrees, maintain 5000' till established cleared ILS approach.' the ILS started to center about the time I was given the clearance. I read the DME as 12, and said to the copilot 'we are established change to the ILS and monitor.' I then descended to 4000'. The controller asked my altitude. I replied, '4000'.' he said, 'turn right 310 and climb to 5000'.' I reported level at 5000'. The controller then said, 'turn left 240 degrees, cleared for approach.' I am not sure if I let down too soon, or if there was conflicting traffic; however, if I did let down too soon, I am sure the controller would have spotted it on his radar after 200 or 300' and advised me, and not have waited until I leveled at 4000'. I feel to safely conduct parallel approachs to pit, DME should be added to the ILS's and the approach procedures clarified. This would greatly reduce the cockpit workload, and reduce the margin of error. It would permit both radios to be tuned to the same navigation aid for xchk purposes, and also reduce the possibility of confusion in the cockpit. Supplemental information from acn 130322: apparently the '18' on the DME was mistaken for a '13', which is kerrs intersection, where we can descend to 4000'.

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Original NASA ASRS Text

Title: ACR LGT FAILED TO FOLLOW IAP ILS APCH INTO PIT. PIC PF STARTED DESCENT FROM 5000', BASED ON A DME READING HE THOUGHT DESIGNATED IAF.

Narrative: WHILE BEING VECTORED FOR AN ILS APCH TO RWY 28R PIT, I WAS GIVEN NUMEROUS HDG, ALT AND AIRSPD CHANGES, WHICH CAUSED A HEAVIER THAN NORMAL COCKPIT WORKLOAD. MY VOR/ILS RADIO WAS TUNED TO THE ILS. THE COPLT'S VOR/ILS RADIO WAS TUNED TO MMJ/VOR FOR DME AND BEARING. THE #2 DME DISPLAY ON MY SIDE STARTED TO DISPLAY #'S WITH SEGMENTS MISSING. I WAS GIVEN CLRNC TO 'TURN RIGHT TO 240 DEGS, MAINTAIN 5000' TILL ESTABLISHED CLRED ILS APCH.' THE ILS STARTED TO CENTER ABOUT THE TIME I WAS GIVEN THE CLRNC. I READ THE DME AS 12, AND SAID TO THE COPLT 'WE ARE ESTABLISHED CHANGE TO THE ILS AND MONITOR.' I THEN DSNDED TO 4000'. THE CTLR ASKED MY ALT. I REPLIED, '4000'.' HE SAID, 'TURN RIGHT 310 AND CLB TO 5000'.' I RPTED LEVEL AT 5000'. THE CTLR THEN SAID, 'TURN LEFT 240 DEGS, CLRED FOR APCH.' I AM NOT SURE IF I LET DOWN TOO SOON, OR IF THERE WAS CONFLICTING TFC; HOWEVER, IF I DID LET DOWN TOO SOON, I AM SURE THE CTLR WOULD HAVE SPOTTED IT ON HIS RADAR AFTER 200 OR 300' AND ADVISED ME, AND NOT HAVE WAITED UNTIL I LEVELED AT 4000'. I FEEL TO SAFELY CONDUCT PARALLEL APCHS TO PIT, DME SHOULD BE ADDED TO THE ILS'S AND THE APCH PROCS CLARIFIED. THIS WOULD GREATLY REDUCE THE COCKPIT WORKLOAD, AND REDUCE THE MARGIN OF ERROR. IT WOULD PERMIT BOTH RADIOS TO BE TUNED TO THE SAME NAV AID FOR XCHK PURPOSES, AND ALSO REDUCE THE POSSIBILITY OF CONFUSION IN THE COCKPIT. SUPPLEMENTAL INFO FROM ACN 130322: APPARENTLY THE '18' ON THE DME WAS MISTAKEN FOR A '13', WHICH IS KERRS INTXN, WHERE WE CAN DSND TO 4000'.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.