Narrative:

While operating under part 91, we were being vectored for the ILS runway 27R at ord. Simultaneous ILS approachs were being conducted to runway 27L and runway 27R. Chicago approach issued us a clearance to descend to 4000 ft MSL. My first officer was the PF and I was performing PNF duties. The first officer was not utilizing the autoplt at the time of this event. During the descent, I asked the first officer to briefly arrest the descent so that the indicated airspeed would decay enough to facilitate flap deployment of 20 degrees. At the time of my request, our altimeter indicated 4200 ft MSL. Very shortly thereafter, we were given an intercept heading for the localizer. I replied to the clearance and reset the heading bug to the intercept heading. A few moments later, we received another radio call from the controller questioning our altitude. At that point, I looked up and our altimeter indicated 5000 ft MSL. I then looked at the altitude alerter, and it indicated 4000 ft. I realized that we were 1000 ft high, and I replied to the controller that 'we are level at 5000 ft. I'm not sure why we stopped the descent.' the controller replied with some urgency, 'it appears that you have been climbing. I have traffic at 5000 ft. I need you at 4000 ft now.' I immediately retarded the power levers and applied forward pressure to the control yoke while simultaneously verbally directing the first officer to descend. I then remembered that we had been at 4200 ft only a few seconds earlier. I realized at that point that the PF, instead of resuming the descent to 4000 ft, had actually climbed back to 5000 ft MSL. Moments after beginning the descent, the TCASII provided a basic TA alert at an altitude of approximately 4500 ft. An aural alert of 'traffic' was heard. There was no RA issued by our TCASII, nor was there an audio warning to descend. The instrument approach was continued. My lack of supervision over the PF's altitude control was a contributing factor. My desire to reduce our airspeed and subsequently deploy 20 degrees of flaps was premature, and could have waited until the PF had stabilized the descent. My PNF duties of replying to the intercept clearance and setting the heading bug contributed to a reduced performance of my supervisory duties. A lack of experience in ord's extremely high density traffic environment was a contributing factor to the lack of situational awareness for both pilots. The PF had never flown into ord, and although I have limited experience at high density airports, prior to this day I had very little if no experience at ord while simultaneous approachs were being conducted to parallel runways. The use of the autoplt during this event could have played a significant role in decreasing our workload and could have prevented our reduction in situational awareness.

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Original NASA ASRS Text

Title: NON COMPLIANCE WITH ALT CLRNC, ALT UNDERSHOT BY THE CREW OF A LEAR 45 ON APCH TO ORD, IL.

Narrative: WHILE OPERATING UNDER PART 91, WE WERE BEING VECTORED FOR THE ILS RWY 27R AT ORD. SIMULTANEOUS ILS APCHS WERE BEING CONDUCTED TO RWY 27L AND RWY 27R. CHICAGO APCH ISSUED US A CLRNC TO DSND TO 4000 FT MSL. MY FO WAS THE PF AND I WAS PERFORMING PNF DUTIES. THE FO WAS NOT UTILIZING THE AUTOPLT AT THE TIME OF THIS EVENT. DURING THE DSCNT, I ASKED THE FO TO BRIEFLY ARREST THE DSCNT SO THAT THE INDICATED AIRSPD WOULD DECAY ENOUGH TO FACILITATE FLAP DEPLOYMENT OF 20 DEGS. AT THE TIME OF MY REQUEST, OUR ALTIMETER INDICATED 4200 FT MSL. VERY SHORTLY THEREAFTER, WE WERE GIVEN AN INTERCEPT HDG FOR THE LOC. I REPLIED TO THE CLRNC AND RESET THE HDG BUG TO THE INTERCEPT HDG. A FEW MOMENTS LATER, WE RECEIVED ANOTHER RADIO CALL FROM THE CTLR QUESTIONING OUR ALT. AT THAT POINT, I LOOKED UP AND OUR ALTIMETER INDICATED 5000 FT MSL. I THEN LOOKED AT THE ALT ALERTER, AND IT INDICATED 4000 FT. I REALIZED THAT WE WERE 1000 FT HIGH, AND I REPLIED TO THE CTLR THAT 'WE ARE LEVEL AT 5000 FT. I'M NOT SURE WHY WE STOPPED THE DSCNT.' THE CTLR REPLIED WITH SOME URGENCY, 'IT APPEARS THAT YOU HAVE BEEN CLBING. I HAVE TFC AT 5000 FT. I NEED YOU AT 4000 FT NOW.' I IMMEDIATELY RETARDED THE PWR LEVERS AND APPLIED FORWARD PRESSURE TO THE CTL YOKE WHILE SIMULTANEOUSLY VERBALLY DIRECTING THE FO TO DSND. I THEN REMEMBERED THAT WE HAD BEEN AT 4200 FT ONLY A FEW SECONDS EARLIER. I REALIZED AT THAT POINT THAT THE PF, INSTEAD OF RESUMING THE DSCNT TO 4000 FT, HAD ACTUALLY CLBED BACK TO 5000 FT MSL. MOMENTS AFTER BEGINNING THE DSCNT, THE TCASII PROVIDED A BASIC TA ALERT AT AN ALT OF APPROX 4500 FT. AN AURAL ALERT OF 'TFC' WAS HEARD. THERE WAS NO RA ISSUED BY OUR TCASII, NOR WAS THERE AN AUDIO WARNING TO DSND. THE INST APCH WAS CONTINUED. MY LACK OF SUPERVISION OVER THE PF'S ALT CTL WAS A CONTRIBUTING FACTOR. MY DESIRE TO REDUCE OUR AIRSPD AND SUBSEQUENTLY DEPLOY 20 DEGS OF FLAPS WAS PREMATURE, AND COULD HAVE WAITED UNTIL THE PF HAD STABILIZED THE DSCNT. MY PNF DUTIES OF REPLYING TO THE INTERCEPT CLRNC AND SETTING THE HDG BUG CONTRIBUTED TO A REDUCED PERFORMANCE OF MY SUPERVISORY DUTIES. A LACK OF EXPERIENCE IN ORD'S EXTREMELY HIGH DENSITY TFC ENVIRONMENT WAS A CONTRIBUTING FACTOR TO THE LACK OF SITUATIONAL AWARENESS FOR BOTH PLTS. THE PF HAD NEVER FLOWN INTO ORD, AND ALTHOUGH I HAVE LIMITED EXPERIENCE AT HIGH DENSITY ARPTS, PRIOR TO THIS DAY I HAD VERY LITTLE IF NO EXPERIENCE AT ORD WHILE SIMULTANEOUS APCHS WERE BEING CONDUCTED TO PARALLEL RWYS. THE USE OF THE AUTOPLT DURING THIS EVENT COULD HAVE PLAYED A SIGNIFICANT ROLE IN DECREASING OUR WORKLOAD AND COULD HAVE PREVENTED OUR REDUCTION IN SITUATIONAL AWARENESS.

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.