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A descending B737-300 overshoots its assigned altitude in a near CFIT 30 mi northeast of boi, identification.
| Attributes | |
| ACN | 482980 |
| Time | |
| Date | 200008 |
| Day | Mon |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | navaid : boi.vortac |
| State Reference | ID |
| Altitude | msl bound lower : 10000 msl bound upper : 13000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zlc.artcc tracon : c90.tracon |
| Operator | common carrier : air carrier |
| Make Model Name | B737-300 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other other vortac |
| Flight Phase | descent : intermediate altitude |
| Route In Use | arrival : on vectors enroute : direct |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : multi engine pilot : atp pilot : flight engineer |
| Experience | flight time last 90 days : 180 flight time total : 7800 flight time type : 1500 |
| ASRS Report | 482980 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : multi engine pilot : instrument pilot : commercial |
| Events | |
| Anomaly | altitude deviation : overshoot non adherence : company policies non adherence : clearance non adherence : far other anomaly other other spatial deviation |
| Independent Detector | aircraft equipment : gpws |
| Resolutory Action | flight crew : became reoriented flight crew : returned to assigned altitude flight crew : took evasive action |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Problem Areas | Airspace Structure Chart Or Publication Flight Crew Human Performance Environmental Factor |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
During descent into boi at night in VMC conditions on the 061 degree radial we were cleared to a lower altitude. The copilot and I both heard 10000 ft and I read back 10000 ft to ATC. ATC later said actual clearance was to 13000 ft. At 10000 ft and about 30 mi we got a GPWS, 'terrain, terrain,' and pull up warning. Standard operating procedures were followed and climb to 13000 ft was accomplished. It was the end of a 9 hour 15 min duty day which isn't all that long, but it was in my own time zone and day 5 flying a reserve schedule. There is no question I was tired. That particular radio frequency was a little scratchy. The little voice in the back of my mind was talking to me and in fact after receiving the clearance I pulled out the en route chart (kind of unusual for most glass pilots) but did not use it properly. I think I was looking for something very specific (an airway with an MEA) to validate the little voice and uneasy feeling I had. I overlooked completely the grid mora of '14.2' and the brown terrain symbol, indicating about 10000 ft of terrain. (There are no numbers on the symbol, may be air carrier specific.) I also checked the MSA on the approach charts (9400 ft) but knew these only go out to 25 NM. I think overlooking the items on the en route chart was partly fatigue related.
Original NASA ASRS Text
Title: A DSNDING B737-300 OVERSHOOTS ITS ASSIGNED ALT IN A NEAR CFIT 30 MI NE OF BOI, ID.
Narrative: DURING DSCNT INTO BOI AT NIGHT IN VMC CONDITIONS ON THE 061 DEG RADIAL WE WERE CLRED TO A LOWER ALT. THE COPLT AND I BOTH HEARD 10000 FT AND I READ BACK 10000 FT TO ATC. ATC LATER SAID ACTUAL CLRNC WAS TO 13000 FT. AT 10000 FT AND ABOUT 30 MI WE GOT A GPWS, 'TERRAIN, TERRAIN,' AND PULL UP WARNING. STANDARD OPERATING PROCS WERE FOLLOWED AND CLB TO 13000 FT WAS ACCOMPLISHED. IT WAS THE END OF A 9 HR 15 MIN DUTY DAY WHICH ISN'T ALL THAT LONG, BUT IT WAS IN MY OWN TIME ZONE AND DAY 5 FLYING A RESERVE SCHEDULE. THERE IS NO QUESTION I WAS TIRED. THAT PARTICULAR RADIO FREQ WAS A LITTLE SCRATCHY. THE LITTLE VOICE IN THE BACK OF MY MIND WAS TALKING TO ME AND IN FACT AFTER RECEIVING THE CLRNC I PULLED OUT THE ENRTE CHART (KIND OF UNUSUAL FOR MOST GLASS PLTS) BUT DID NOT USE IT PROPERLY. I THINK I WAS LOOKING FOR SOMETHING VERY SPECIFIC (AN AIRWAY WITH AN MEA) TO VALIDATE THE LITTLE VOICE AND UNEASY FEELING I HAD. I OVERLOOKED COMPLETELY THE GRID MORA OF '14.2' AND THE BROWN TERRAIN SYMBOL, INDICATING ABOUT 10000 FT OF TERRAIN. (THERE ARE NO NUMBERS ON THE SYMBOL, MAY BE ACR SPECIFIC.) I ALSO CHKED THE MSA ON THE APCH CHARTS (9400 FT) BUT KNEW THESE ONLY GO OUT TO 25 NM. I THINK OVERLOOKING THE ITEMS ON THE ENRTE CHART WAS PARTLY FATIGUE RELATED.
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.