 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Flight crew of a B727-200 descended below assigned altitude due to ATC not hearing readback correctly from flight crew, or thought that they had given a higher altitude originally.
| Attributes | |
| ACN | 384400 |
| Time | |
| Date | 199710 |
| Day | Mon |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : den |
| State Reference | CO |
| Altitude | msl bound lower : 12000 msl bound upper : 13000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : den |
| Operator | common carrier : air carrier |
| Make Model Name | B727-200 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | descent other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 300 flight time total : 20400 flight time type : 2000 |
| ASRS Report | 384400 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | other other : other pilot : flight engineer pilot : atp |
| Experience | flight time last 90 days : 80 flight time total : 7700 |
| ASRS Report | 384398 |
| Events | |
| Anomaly | altitude deviation : overshoot non adherence : clearance |
| Independent Detector | other controllera |
| Resolutory Action | other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Approaching den received clearance to 11000 ft. All 3 crew members heard 11000 ft. I read back 11000 ft. With no controller response to indicate otherwise, departed FL190 for 11000 ft. At 12000 ft TRACON asked our altitude. I responded 'leaving 12000 ft for 11000 ft.' he told us to turn left 60 degrees and said our assigned altitude was 13000 ft. I responded that I read back 11000 ft, to which he did not respond. Just another hearback/readback error. ATC workload is such that they seem not able to keep up with readbacks.
Original NASA ASRS Text
Title: FLC OF A B727-200 DSNDED BELOW ASSIGNED ALT DUE TO ATC NOT HEARING READBACK CORRECTLY FROM FLC, OR THOUGHT THAT THEY HAD GIVEN A HIGHER ALT ORIGINALLY.
Narrative: APCHING DEN RECEIVED CLRNC TO 11000 FT. ALL 3 CREW MEMBERS HEARD 11000 FT. I READ BACK 11000 FT. WITH NO CTLR RESPONSE TO INDICATE OTHERWISE, DEPARTED FL190 FOR 11000 FT. AT 12000 FT TRACON ASKED OUR ALT. I RESPONDED 'LEAVING 12000 FT FOR 11000 FT.' HE TOLD US TO TURN L 60 DEGS AND SAID OUR ASSIGNED ALT WAS 13000 FT. I RESPONDED THAT I READ BACK 11000 FT, TO WHICH HE DID NOT RESPOND. JUST ANOTHER HEARBACK/READBACK ERROR. ATC WORKLOAD IS SUCH THAT THEY SEEM NOT ABLE TO KEEP UP WITH READBACKS.
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.