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Flight crew of medium large transport climbing to FL230 advised by center their clearance was to FL220.
| Attributes | |
| ACN | 127899 |
| Time | |
| Date | 198911 |
| Day | Fri |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : bpr |
| State Reference | TX |
| Altitude | msl bound lower : 22000 msl bound upper : 22500 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : dfw |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Flight Phase | climbout : intermediate altitude cruise other |
| Route In Use | enroute : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : commercial pilot : instrument |
| Experience | flight time last 90 days : 180 flight time total : 11400 flight time type : 5800 |
| ASRS Report | 127889 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument pilot : flight engineer pilot : atp |
| Experience | flight time last 90 days : 150 flight time total : 3000 flight time type : 300 |
| ASRS Report | 128001 |
| Events | |
| Anomaly | altitude deviation : overshoot other anomaly other |
| Independent Detector | other controllera |
| Resolutory Action | flight crew : overcame equipment problem flight crew : returned to intended course or assigned course |
| Consequence | faa : assigned or threatened penalties |
| Supplementary | |
| Primary Problem | Ambiguous |
| Air Traffic Incident | other |
Narrative:
We were (or thought we were) cleared to FL230, our filed cruise altitude. Passing about FL190 we were vectored east of course for traffic. Passing FL200 we were cleared direct bpr. At FL225 ZFW said to check our altitude, as we were cleared to FL220. We immediately descended to FL220 and continued on course with no further action. I still think we were cleared to FL230. Obviously there was a breakdown in communication somewhere. Only the recorded xmissions are the final proof. I feel the controller's handbook needs to be changed to require him to acknowledge our ATC readbacks. It is my experience that only about 1/3 of our readbacks are acknowledged by center, and if you consider approach/departure control, the percentage of readback acknowledgement is very low. Many times I have asked center to acknowledge my readback of his instructions to me. Often I must repeat my readback to him, as he doesn't know if my readback was correct. The controller's required acknowledgement would provide for a safer operation, as it would help to reassure the pilot correctly understands the clearance and would help to prevent excessive communication by the pilot asking for acknowledgement, and then often having to repeat readbacks.
Original NASA ASRS Text
Title: FLT CREW OF MLG CLIMBING TO FL230 ADVISED BY CENTER THEIR CLRNC WAS TO FL220.
Narrative: WE WERE (OR THOUGHT WE WERE) CLRED TO FL230, OUR FILED CRUISE ALT. PASSING ABOUT FL190 WE WERE VECTORED E OF COURSE FOR TFC. PASSING FL200 WE WERE CLRED DIRECT BPR. AT FL225 ZFW SAID TO CHK OUR ALT, AS WE WERE CLRED TO FL220. WE IMMEDIATELY DSNDED TO FL220 AND CONTINUED ON COURSE WITH NO FURTHER ACTION. I STILL THINK WE WERE CLRED TO FL230. OBVIOUSLY THERE WAS A BREAKDOWN IN COM SOMEWHERE. ONLY THE RECORDED XMISSIONS ARE THE FINAL PROOF. I FEEL THE CTLR'S HANDBOOK NEEDS TO BE CHANGED TO REQUIRE HIM TO ACKNOWLEDGE OUR ATC READBACKS. IT IS MY EXPERIENCE THAT ONLY ABOUT 1/3 OF OUR READBACKS ARE ACKNOWLEDGED BY CENTER, AND IF YOU CONSIDER APCH/DEP CTL, THE PERCENTAGE OF READBACK ACKNOWLEDGEMENT IS VERY LOW. MANY TIMES I HAVE ASKED CENTER TO ACKNOWLEDGE MY READBACK OF HIS INSTRUCTIONS TO ME. OFTEN I MUST REPEAT MY READBACK TO HIM, AS HE DOESN'T KNOW IF MY READBACK WAS CORRECT. THE CTLR'S REQUIRED ACKNOWLEDGEMENT WOULD PROVIDE FOR A SAFER OPERATION, AS IT WOULD HELP TO REASSURE THE PLT CORRECTLY UNDERSTANDS THE CLRNC AND WOULD HELP TO PREVENT EXCESSIVE COM BY THE PLT ASKING FOR ACKNOWLEDGEMENT, AND THEN OFTEN HAVING TO REPEAT READBACKS.
Data retrieved from NASA's ASRS site as of August 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.