Narrative:

We were on radar vectors to the ILS runway 26 at iah, and due to traffic congestion, we were issued a turn to intercept the ILS runway 27 from 4000 ft MSL. At this point we were 17 mi east of iah, upon ILS capture and below the GS following a B757 (5 mi ahead). I intended to capture the GS at 12 DME east, however, I failed to note the mandatory approach altitudes for this precision approach at (14.5 DME, 3000 ft) and at (10.0 DME, 2000 ft). Fortunately our controller issued a frequency change and reminded us of the mandatory altitudes, however, I missed the 14.5 DME restr of 3000 ft by 500 ft. The 10.0 DME, 2000 ft restr was met, however, in IMC or VMC this posed a safety risk due to the 5 mi spacing behind a boeing B757. This problem could have been avoided had a correct briefing of these step-down altitudes had been made or a reminder by the approach controller of this new ILS approach, dated march 2000.

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Original NASA ASRS Text

Title: LAST MIN APCH RWY CHANGE AT IAH COMES TOO LATE FOR CREW OF B737 TO MEET THE FIRST XING RESTR ON THE NEW APCH.

Narrative: WE WERE ON RADAR VECTORS TO THE ILS RWY 26 AT IAH, AND DUE TO TFC CONGESTION, WE WERE ISSUED A TURN TO INTERCEPT THE ILS RWY 27 FROM 4000 FT MSL. AT THIS POINT WE WERE 17 MI E OF IAH, UPON ILS CAPTURE AND BELOW THE GS FOLLOWING A B757 (5 MI AHEAD). I INTENDED TO CAPTURE THE GS AT 12 DME E, HOWEVER, I FAILED TO NOTE THE MANDATORY APCH ALTS FOR THIS PRECISION APCH AT (14.5 DME, 3000 FT) AND AT (10.0 DME, 2000 FT). FORTUNATELY OUR CTLR ISSUED A FREQ CHANGE AND REMINDED US OF THE MANDATORY ALTS, HOWEVER, I MISSED THE 14.5 DME RESTR OF 3000 FT BY 500 FT. THE 10.0 DME, 2000 FT RESTR WAS MET, HOWEVER, IN IMC OR VMC THIS POSED A SAFETY RISK DUE TO THE 5 MI SPACING BEHIND A BOEING B757. THIS PROB COULD HAVE BEEN AVOIDED HAD A CORRECT BRIEFING OF THESE STEP-DOWN ALTS HAD BEEN MADE OR A REMINDER BY THE APCH CTLR OF THIS NEW ILS APCH, DATED MARCH 2000.

Data retrieved from NASA's ASRS site as of July 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.