Narrative:

We were conducting attitude instrument flight training in VFR conditions above scattered/layered clouds. We called for and received a 'pop-up' clearance to long beach and were told to descend to 4000 ft on 090 degree heading (from 6500 ft). Approach called at 3000 ft that we had been told to maintain 4000 ft. We immediately began a climb back to 4000 ft, and heard ATC call us as traffic to an airliner. We never had visual with him as clouds were scattered and layered. I was instructing a student beginning instrument training. We were descending at 1000 FPM and explaining what ATC was doing and expecting from us as we were descending back to lgb. It was discovered by ATC calling us to maintain 4000 ft. Corrective action is to always call out to yourself ft- remaining-to assigned altitude, particularly 1000-to-go, 300- to-go, and 100-to-go, and not get so involved in instructing that you don't pay attention to altitude. Another contributing factor was the VMC conditions, and I was looking outside at upcoming clouds ahead which we would've been in rather than below, if we'd leveled at 4000 ft as we should have subconsciously maintaining VFR? ATC had queried us about sky conditions, possibly another contributing factor. (We had even written down the assigned altitude, so that is not necessarily insurance against altdevs!)

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Original NASA ASRS Text

Title: FLC OF AN SMA TRAINING ACFT INADVERTENTLY OVERSHOT DSCNT ALT ASSIGNMENT DUE TO INSTRUCTIONAL DISTR.

Narrative: WE WERE CONDUCTING ATTITUDE INST FLT TRAINING IN VFR CONDITIONS ABOVE SCATTERED/LAYERED CLOUDS. WE CALLED FOR AND RECEIVED A 'POP-UP' CLRNC TO LONG BEACH AND WERE TOLD TO DSND TO 4000 FT ON 090 DEG HDG (FROM 6500 FT). APCH CALLED AT 3000 FT THAT WE HAD BEEN TOLD TO MAINTAIN 4000 FT. WE IMMEDIATELY BEGAN A CLB BACK TO 4000 FT, AND HEARD ATC CALL US AS TFC TO AN AIRLINER. WE NEVER HAD VISUAL WITH HIM AS CLOUDS WERE SCATTERED AND LAYERED. I WAS INSTRUCTING A STUDENT BEGINNING INST TRAINING. WE WERE DSNDING AT 1000 FPM AND EXPLAINING WHAT ATC WAS DOING AND EXPECTING FROM US AS WE WERE DSNDING BACK TO LGB. IT WAS DISCOVERED BY ATC CALLING US TO MAINTAIN 4000 FT. CORRECTIVE ACTION IS TO ALWAYS CALL OUT TO YOURSELF FT- REMAINING-TO ASSIGNED ALT, PARTICULARLY 1000-TO-GO, 300- TO-GO, AND 100-TO-GO, AND NOT GET SO INVOLVED IN INSTRUCTING THAT YOU DON'T PAY ATTN TO ALT. ANOTHER CONTRIBUTING FACTOR WAS THE VMC CONDITIONS, AND I WAS LOOKING OUTSIDE AT UPCOMING CLOUDS AHEAD WHICH WE WOULD'VE BEEN IN RATHER THAN BELOW, IF WE'D LEVELED AT 4000 FT AS WE SHOULD HAVE SUBCONSCIOUSLY MAINTAINING VFR? ATC HAD QUERIED US ABOUT SKY CONDITIONS, POSSIBLY ANOTHER CONTRIBUTING FACTOR. (WE HAD EVEN WRITTEN DOWN THE ASSIGNED ALT, SO THAT IS NOT NECESSARILY INSURANCE AGAINST ALTDEVS!)

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.