Narrative:

All 3 of us in the cockpit had our 17L and 18R approach charts and the airport taxi diagram available. Because it was night time and dfw was not a report we frequented, the ILS 17L and planned landing and runway clearing procedure had been briefed in detail, with the 18R chart at the ready 'just in case.' the radios were all tuned for the ILS 17L approach, and the aircraft was being hand-flown. We were on a modified base leg, descending to 5000 ft MSL quite close in, having been led to expect a visual 'slam dunk.' the call 'out of 6000 for 5000' had just been made by the PNF and acknowledged by the PF, and the power was started up for the level-off when ATC said 'change runways to 18R, advise the runway in sight.' we were less than 10 mi out, almost 5000 ft higher than the runways. Despite all our supposedly good sense, all 3 of us simultaneously began to switch approach charts, check the runway 18R ILS frequency and go 'head down,' all while we were supposedly hand flying the aircraft in a level-off at 5000 ft MSL. The altitude alert tone and light shocked all 3 of us back to our senses as we passed 250- 300 ft below our assigned altitude. Even with the immediate thrust increase and pitch-up, our inertia carried us to 400 ft low (4600 MSL). We were back at 5000 literally in seconds, and fortunately, no other aircraft were in the vicinity. No one from ATC mentioned anything, so we do not know whether our momentary excursion even registered with them. But the 3 of us in the cockpit all felt that we had broken trust with each other, our passenger, and the system by failing to maintain basic discipline and failing to adhere to correct prioritization of tasks and division of duties, the most simple CRM. Always, 1 pilot must do nothing else but fly the aircraft. (Suitably humbled, we saw runway 18R and successfully uneventfully landed).

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Original NASA ASRS Text

Title: CAPT OF ACR LGT ACFT ALLOWED ACFT TO OVERSHOOT ASSIGNED ALT DURING DSCNT. (ALT EXCURSION).

Narrative: ALL 3 OF US IN THE COCKPIT HAD OUR 17L AND 18R APCH CHARTS AND THE ARPT TAXI DIAGRAM AVAILABLE. BECAUSE IT WAS NIGHT TIME AND DFW WAS NOT A RPT WE FREQUENTED, THE ILS 17L AND PLANNED LNDG AND RWY CLRING PROC HAD BEEN BRIEFED IN DETAIL, WITH THE 18R CHART AT THE READY 'JUST IN CASE.' THE RADIOS WERE ALL TUNED FOR THE ILS 17L APCH, AND THE ACFT WAS BEING HAND-FLOWN. WE WERE ON A MODIFIED BASE LEG, DSNDING TO 5000 FT MSL QUITE CLOSE IN, HAVING BEEN LED TO EXPECT A VISUAL 'SLAM DUNK.' THE CALL 'OUT OF 6000 FOR 5000' HAD JUST BEEN MADE BY THE PNF AND ACKNOWLEDGED BY THE PF, AND THE PWR WAS STARTED UP FOR THE LEVEL-OFF WHEN ATC SAID 'CHANGE RWYS TO 18R, ADVISE THE RWY IN SIGHT.' WE WERE LESS THAN 10 MI OUT, ALMOST 5000 FT HIGHER THAN THE RWYS. DESPITE ALL OUR SUPPOSEDLY GOOD SENSE, ALL 3 OF US SIMULTANEOUSLY BEGAN TO SWITCH APCH CHARTS, CHK THE RWY 18R ILS FREQ AND GO 'HEAD DOWN,' ALL WHILE WE WERE SUPPOSEDLY HAND FLYING THE ACFT IN A LEVEL-OFF AT 5000 FT MSL. THE ALT ALERT TONE AND LIGHT SHOCKED ALL 3 OF US BACK TO OUR SENSES AS WE PASSED 250- 300 FT BELOW OUR ASSIGNED ALT. EVEN WITH THE IMMEDIATE THRUST INCREASE AND PITCH-UP, OUR INERTIA CARRIED US TO 400 FT LOW (4600 MSL). WE WERE BACK AT 5000 LITERALLY IN SECONDS, AND FORTUNATELY, NO OTHER ACFT WERE IN THE VICINITY. NO ONE FROM ATC MENTIONED ANYTHING, SO WE DO NOT KNOW WHETHER OUR MOMENTARY EXCURSION EVEN REGISTERED WITH THEM. BUT THE 3 OF US IN THE COCKPIT ALL FELT THAT WE HAD BROKEN TRUST WITH EACH OTHER, OUR PAX, AND THE SYS BY FAILING TO MAINTAIN BASIC DISCIPLINE AND FAILING TO ADHERE TO CORRECT PRIORITIZATION OF TASKS AND DIVISION OF DUTIES, THE MOST SIMPLE CRM. ALWAYS, 1 PLT MUST DO NOTHING ELSE BUT FLY THE ACFT. (SUITABLY HUMBLED, WE SAW RWY 18R AND SUCCESSFULLY UNEVENTFULLY LANDED).

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.