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A cga LR35 climbed above assigned altitude after takeoff. The reporter claims they read back the altitude they thought that they were cleared to and the controller did not correct the readback.
| Attributes | |
| ACN | 351920 |
| Time | |
| Date | 199611 |
| Day | Fri |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | airport : dca |
| State Reference | DC |
| Altitude | msl bound lower : 10000 msl bound upper : 11000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tracon : dca |
| Operator | general aviation : corporate |
| Make Model Name | Learjet 35 |
| Operating Under FAR Part | Part 91 |
| Flight Phase | climbout : initial |
| Route In Use | departure other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : instrument pilot : cfi pilot : atp |
| Experience | flight time last 90 days : 135 flight time total : 16000 flight time type : 2200 |
| ASRS Report | 351920 |
| Person 2 | |
| Affiliation | Other |
| Function | flight crew : first officer |
| Qualification | pilot : atp pilot : flight engineer pilot : cfi |
| Experience | flight time last 90 days : 120 flight time total : 18500 flight time type : 2 |
| ASRS Report | 351910 |
| Events | |
| Anomaly | altitude deviation : overshoot non adherence : clearance |
| Independent Detector | other controllera |
| Resolutory Action | controller : issued new clearance other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | other |
Narrative:
Statement regarding altitude deviation by a learjet in nov 1996, at approximately XX25 lst, southwest of ZDC. During climb out the copilot was flying and monitoring the ATC radio while the captain was engaged in other cockpit duties. Either during climb, or shortly after reaching an assigned altitude of 10000 ft, the copilot understood that the controller cleared us to climb to and maintain 11000 ft. We agreed with each other that 11000 ft was our newly assigned altitude. The copilot read back the climb clearance to ATC, indicating our understanding that we were cleared to climb to 11000 ft. We set 11000 ft in the altitude selector and proceeded to climb to 11000 ft. Upon arrival at that altitude, the controller asked us our altitude and we replied that we were level at 11000 ft as assigned. The controller advised that we had been cleared only to 10000 ft and asked that we descend back to that altitude, which we did. There were no apparent traffic conflicts as a result of this misunderstanding. We advised the controller that we both understood that we had been cleared to 11000 ft, and that we had read back the clearance and had not received a correction. 2 questions arise as a result of this incident. One, how did both pilots understand that they had been cleared to 11000 ft, when in fact, they had not. (Is it possible that they responded to a clearance for another aircraft?) and two, when the copilot read back the climb clearance to the controller, why did he not issue a correction? The answer to either question is not readily apparent.
Original NASA ASRS Text
Title: A CGA LR35 CLBED ABOVE ASSIGNED ALT AFTER TKOF. THE RPTR CLAIMS THEY READ BACK THE ALT THEY THOUGHT THAT THEY WERE CLRED TO AND THE CTLR DID NOT CORRECT THE READBACK.
Narrative: STATEMENT REGARDING ALTDEV BY A LEARJET IN NOV 1996, AT APPROX XX25 LST, SW OF ZDC. DURING CLBOUT THE COPLT WAS FLYING AND MONITORING THE ATC RADIO WHILE THE CAPT WAS ENGAGED IN OTHER COCKPIT DUTIES. EITHER DURING CLB, OR SHORTLY AFTER REACHING AN ASSIGNED ALT OF 10000 FT, THE COPLT UNDERSTOOD THAT THE CTLR CLRED US TO CLB TO AND MAINTAIN 11000 FT. WE AGREED WITH EACH OTHER THAT 11000 FT WAS OUR NEWLY ASSIGNED ALT. THE COPLT READ BACK THE CLB CLRNC TO ATC, INDICATING OUR UNDERSTANDING THAT WE WERE CLRED TO CLB TO 11000 FT. WE SET 11000 FT IN THE ALT SELECTOR AND PROCEEDED TO CLB TO 11000 FT. UPON ARR AT THAT ALT, THE CTLR ASKED US OUR ALT AND WE REPLIED THAT WE WERE LEVEL AT 11000 FT AS ASSIGNED. THE CTLR ADVISED THAT WE HAD BEEN CLRED ONLY TO 10000 FT AND ASKED THAT WE DSND BACK TO THAT ALT, WHICH WE DID. THERE WERE NO APPARENT TFC CONFLICTS AS A RESULT OF THIS MISUNDERSTANDING. WE ADVISED THE CTLR THAT WE BOTH UNDERSTOOD THAT WE HAD BEEN CLRED TO 11000 FT, AND THAT WE HAD READ BACK THE CLRNC AND HAD NOT RECEIVED A CORRECTION. 2 QUESTIONS ARISE AS A RESULT OF THIS INCIDENT. ONE, HOW DID BOTH PLTS UNDERSTAND THAT THEY HAD BEEN CLRED TO 11000 FT, WHEN IN FACT, THEY HAD NOT. (IS IT POSSIBLE THAT THEY RESPONDED TO A CLRNC FOR ANOTHER ACFT?) AND TWO, WHEN THE COPLT READ BACK THE CLB CLRNC TO THE CTLR, WHY DID HE NOT ISSUE A CORRECTION? THE ANSWER TO EITHER QUESTION IS NOT READILY APPARENT.
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.