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A lear flight crew climbs to and through opposite direction traffic's altitude when the PIC misunderstands the center controller's transmission.
| Attributes | |
| ACN | 423243 |
| Time | |
| Date | 199812 |
| Day | Thu |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : bfl |
| State Reference | CA |
| Altitude | msl bound lower : 28000 msl bound upper : 29000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Operator | general aviation : personal |
| Make Model Name | Learjet 25 |
| Flight Phase | cruise other |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | B737 Undifferentiated or Other Model |
| Flight Phase | cruise other descent other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : first officer |
| Qualification | pilot : instrument |
| Experience | flight time last 90 days : 44 flight time total : 11100 flight time type : 5400 |
| ASRS Report | 423243 |
| Person 2 | |
| Affiliation | Other |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : instrument |
| Experience | flight time last 90 days : 25 flight time total : 4000 flight time type : 250 |
| ASRS Report | 423246 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : far other anomaly other |
| Independent Detector | other controllera other flight crewa |
| Resolutory Action | flight crew : became reoriented |
| Consequence | faa : reviewed incident with flight crew |
| Miss Distance | horizontal : 6000 vertical : 500 |
| Supplementary | |
| Air Traffic Incident | Pilot Deviation |
Narrative:
On dec/xa/98, I was performing copilot duties in a learjet while on a flight from vny to sac. We had filed for FL350 but experienced numerous intermediate leveloffs by the time we reached FL280. ZLA issued a TA of 'traffic at 12 O'clock, 15 mi, FL290, expect higher altitude after clear of the traffic.' I acknowledged the call. The PF said to me, 'did he say FL290?' and I answered, 'affirmative.' the PF took my answer to mean that we were cleared to climb to FL290 since he did not realize it was a TA. He changed the altitude alerter to FL290 and started to climb. Because I was performing other duties, I did not notice the new alert altitude or the climb. Center then said, 'say your altitude.' I saw we were 1000 ft too high and said, 'take it down' to the PF. Both of us pushed forward on the yoke and I answered to center that we were at FL285 and descending. At that time I visually picked up the opposing traffic at 12:30 O'clock position and about 5 mi. Since the traffic was also descending to avoid our altitude, we did an immediate leveloff and let the traffic stay below us and pass off our right wing. After clear of the traffic, center cleared us to FL310 and asked us to contact them by telephone after landing, which we did. I believe the numerous intermediate leveloffs contributed to the problem. The PF who did not hear the TA thought that this was another 1000 ft climb in the process of getting to FL350. He saw that I was busy with other duties and changed the altitude alerter for me. Because he leveled off at FL280 at climb speed, he kept a high power setting to build airspeed before the next climb so I did not detect a power change when he started the climb. After this occurrence, we have a new procedure where only the PNF sets the altitude alerter. If the PF believes it has been set incorrectly, then he questions the PNF before changing altitude. If there is still a question then we would rechk with the controling agency or charts as necessary.
Original NASA ASRS Text
Title: A LEAR FLC CLBS TO AND THROUGH OPPOSITE DIRECTION TFC'S ALT WHEN THE PIC MISUNDERSTANDS THE CTR CTLR'S XMISSION.
Narrative: ON DEC/XA/98, I WAS PERFORMING COPLT DUTIES IN A LEARJET WHILE ON A FLT FROM VNY TO SAC. WE HAD FILED FOR FL350 BUT EXPERIENCED NUMEROUS INTERMEDIATE LEVELOFFS BY THE TIME WE REACHED FL280. ZLA ISSUED A TA OF 'TFC AT 12 O'CLOCK, 15 MI, FL290, EXPECT HIGHER ALT AFTER CLR OF THE TFC.' I ACKNOWLEDGED THE CALL. THE PF SAID TO ME, 'DID HE SAY FL290?' AND I ANSWERED, 'AFFIRMATIVE.' THE PF TOOK MY ANSWER TO MEAN THAT WE WERE CLRED TO CLB TO FL290 SINCE HE DID NOT REALIZE IT WAS A TA. HE CHANGED THE ALT ALERTER TO FL290 AND STARTED TO CLB. BECAUSE I WAS PERFORMING OTHER DUTIES, I DID NOT NOTICE THE NEW ALERT ALT OR THE CLB. CTR THEN SAID, 'SAY YOUR ALT.' I SAW WE WERE 1000 FT TOO HIGH AND SAID, 'TAKE IT DOWN' TO THE PF. BOTH OF US PUSHED FORWARD ON THE YOKE AND I ANSWERED TO CTR THAT WE WERE AT FL285 AND DSNDING. AT THAT TIME I VISUALLY PICKED UP THE OPPOSING TFC AT 12:30 O'CLOCK POS AND ABOUT 5 MI. SINCE THE TFC WAS ALSO DSNDING TO AVOID OUR ALT, WE DID AN IMMEDIATE LEVELOFF AND LET THE TFC STAY BELOW US AND PASS OFF OUR R WING. AFTER CLR OF THE TFC, CTR CLRED US TO FL310 AND ASKED US TO CONTACT THEM BY TELEPHONE AFTER LNDG, WHICH WE DID. I BELIEVE THE NUMEROUS INTERMEDIATE LEVELOFFS CONTRIBUTED TO THE PROB. THE PF WHO DID NOT HEAR THE TA THOUGHT THAT THIS WAS ANOTHER 1000 FT CLB IN THE PROCESS OF GETTING TO FL350. HE SAW THAT I WAS BUSY WITH OTHER DUTIES AND CHANGED THE ALT ALERTER FOR ME. BECAUSE HE LEVELED OFF AT FL280 AT CLB SPD, HE KEPT A HIGH PWR SETTING TO BUILD AIRSPD BEFORE THE NEXT CLB SO I DID NOT DETECT A PWR CHANGE WHEN HE STARTED THE CLB. AFTER THIS OCCURRENCE, WE HAVE A NEW PROC WHERE ONLY THE PNF SETS THE ALT ALERTER. IF THE PF BELIEVES IT HAS BEEN SET INCORRECTLY, THEN HE QUESTIONS THE PNF BEFORE CHANGING ALT. IF THERE IS STILL A QUESTION THEN WE WOULD RECHK WITH THE CTLING AGENCY OR CHARTS AS NECESSARY.
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.