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An air carrier flight crew flying an unidented turbojet aircraft into ord reports a misunderstanding concerning ATC instructions and the apparent failure of ATC to correct the flight crew clearance readback.
| Attributes | |
| ACN | 452196 |
| Time | |
| Date | 199910 |
| Day | Fri |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | atc facility : zau.artcc |
| State Reference | IL |
| Altitude | msl single value : 10600 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zau.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other |
| Flight Phase | descent : intermediate altitude |
| Route In Use | arrival : profile descent |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : multi engine pilot : cfi pilot : commercial pilot : flight engineer pilot : instrument |
| Experience | flight time last 90 days : 220 flight time total : 4800 flight time type : 1800 |
| ASRS Report | 452196 |
| Person 2 | |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : multi engine pilot : atp |
| Events | |
| Anomaly | altitude deviation : crossing restriction not met non adherence : clearance |
| Resolutory Action | controller : issued new clearance none taken : anomaly accepted |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance FAA ATC Human Performance |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Descending into ord we were told to cross 40 mi southwest of ord at 10000 ft MSL. For that descent, we were already 2500 ft high on the descent profile. I increased speed and used speed brakes to aid the descent. At 10800 ft we were told to slow to 250 KIAS. The captain responded by saying 'if we have to slow, we won't make 10000 ft by 40 mi out of ord.' center responded with 'you were cleared to 11000 ft. Climb back to 11000 ft and slow to 250 KTS.' the lowest we got was 10600 ft. I believe the clearance was to 10000 ft and I know it was read back as 'descend to 10000 ft -- one zero thousand ft' as our operations manual recommends. This may be part of the don't correct readbacks a recent interpretation by the FAA. I also believe that my corrective action of disconnecting the autoplt and getting back to 11000 ft from 10600 ft didn't cause a conflict in traffic.
Original NASA ASRS Text
Title: AN ACR FLC FLYING AN UNIDENTED TURBOJET ACFT INTO ORD RPTS A MISUNDERSTANDING CONCERNING ATC INSTRUCTIONS AND THE APPARENT FAILURE OF ATC TO CORRECT THE FLC CLRNC READBACK.
Narrative: DSNDING INTO ORD WE WERE TOLD TO CROSS 40 MI SW OF ORD AT 10000 FT MSL. FOR THAT DSCNT, WE WERE ALREADY 2500 FT HIGH ON THE DSCNT PROFILE. I INCREASED SPD AND USED SPD BRAKES TO AID THE DSCNT. AT 10800 FT WE WERE TOLD TO SLOW TO 250 KIAS. THE CAPT RESPONDED BY SAYING 'IF WE HAVE TO SLOW, WE WON'T MAKE 10000 FT BY 40 MI OUT OF ORD.' CTR RESPONDED WITH 'YOU WERE CLRED TO 11000 FT. CLB BACK TO 11000 FT AND SLOW TO 250 KTS.' THE LOWEST WE GOT WAS 10600 FT. I BELIEVE THE CLRNC WAS TO 10000 FT AND I KNOW IT WAS READ BACK AS 'DSND TO 10000 FT -- ONE ZERO THOUSAND FT' AS OUR OPERATIONS MANUAL RECOMMENDS. THIS MAY BE PART OF THE DON'T CORRECT READBACKS A RECENT INTERP BY THE FAA. I ALSO BELIEVE THAT MY CORRECTIVE ACTION OF DISCONNECTING THE AUTOPLT AND GETTING BACK TO 11000 FT FROM 10600 FT DIDN'T CAUSE A CONFLICT IN TFC.
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.