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The flight crew of a B737-300 undershot assigned crossing restr on a STAR arrival due to the FMC did not perform as they believed it was set.
| Attributes | |
| ACN | 449320 |
| Time | |
| Date | 199909 |
| Day | Wed |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| State Reference | OH |
| Altitude | msl bound lower : 19000 msl bound upper : 21000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zob.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | B737-300 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other |
| Flight Phase | descent : intermediate altitude descent : vacating altitude |
| Route In Use | arrival star : wiske.wiske 1 |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : multi engine pilot : instrument pilot : commercial pilot : atp |
| Experience | flight time last 90 days : 100 flight time total : 4500 flight time type : 100 |
| ASRS Report | 449320 |
| Person 2 | |
| Affiliation | government : faa |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 115 flight time total : 13500 flight time type : 2000 |
| ASRS Report | 449103 |
| Events | |
| Anomaly | altitude deviation : crossing restriction not met altitude deviation : undershoot non adherence : clearance non adherence : far |
| Independent Detector | aircraft equipment other aircraft equipment : altimeter other flight crewa other flight crewb |
| Resolutory Action | other |
| Consequence | Other |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Sector a gave altitude crossing restr of FL240 25 mi west of ctw. I programmed FMC for this restr. We were then handed off to sector B who revised restr to FL190 10 mi west of ctw. I reprogrammed FMC for new restr and selected the capture function on the descent page of FMC. Aircraft began a 1000 FPM descent and I watched the mileage countdown on descent page to meet restr. When mileage countdown hit '0,' the aircraft did not pull throttle to idle and begin high rate of descent. I then went back to route legs page and saw I had 7 mi to restr point and approximately 6000 ft to lose. I immediately extended speed brakes and increased descent rate to 5500 FPM which put me at maximum operating speed. I missed restr by 1000-1500 ft. No comment from center. Captain and I reviewed our programming of FMC but found no errors in what we did. I did learn I need to go back to raw data to xchk automation.
Original NASA ASRS Text
Title: THE FLC OF A B737-300 UNDERSHOT ASSIGNED XING RESTR ON A STAR ARR DUE TO THE FMC DID NOT PERFORM AS THEY BELIEVED IT WAS SET.
Narrative: SECTOR A GAVE ALT XING RESTR OF FL240 25 MI W OF CTW. I PROGRAMMED FMC FOR THIS RESTR. WE WERE THEN HANDED OFF TO SECTOR B WHO REVISED RESTR TO FL190 10 MI W OF CTW. I REPROGRAMMED FMC FOR NEW RESTR AND SELECTED THE CAPTURE FUNCTION ON THE DSCNT PAGE OF FMC. ACFT BEGAN A 1000 FPM DSCNT AND I WATCHED THE MILEAGE COUNTDOWN ON DSCNT PAGE TO MEET RESTR. WHEN MILEAGE COUNTDOWN HIT '0,' THE ACFT DID NOT PULL THROTTLE TO IDLE AND BEGIN HIGH RATE OF DSCNT. I THEN WENT BACK TO RTE LEGS PAGE AND SAW I HAD 7 MI TO RESTR POINT AND APPROX 6000 FT TO LOSE. I IMMEDIATELY EXTENDED SPD BRAKES AND INCREASED DSCNT RATE TO 5500 FPM WHICH PUT ME AT MAX OPERATING SPD. I MISSED RESTR BY 1000-1500 FT. NO COMMENT FROM CTR. CAPT AND I REVIEWED OUR PROGRAMMING OF FMC BUT FOUND NO ERRORS IN WHAT WE DID. I DID LEARN I NEED TO GO BACK TO RAW DATA TO XCHK AUTOMATION.
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.