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An LR35 atx PIC leaves his assigned altitude when the crew misunderstands the clearance as an 'anticipate' rather than actually being cleared for a specific altitude over franx, pq.
| Attributes | |
| ACN | 485503 |
| Time | |
| Date | 200009 |
| Day | Mon |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | intersection : franx |
| State Reference | PQ |
| Altitude | msl bound lower : 22500 msl bound upper : 24000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : roa.tracon |
| Operator | common carrier : air taxi |
| Make Model Name | Learjet 35 |
| Operating Under FAR Part | Part 135 |
| Navigation In Use | other |
| Flight Phase | descent : vacating altitude |
| Route In Use | arrival : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air taxi |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : flight engineer pilot : instrument pilot : multi engine pilot : cfi |
| Experience | flight time last 90 days : 100 flight time total : 3300 flight time type : 400 |
| ASRS Report | 485503 |
| Person 2 | |
| Affiliation | company : air taxi |
| Function | flight crew : first officer |
| Qualification | pilot : multi engine pilot : instrument pilot : commercial |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other |
| Independent Detector | other controllera |
| Resolutory Action | none taken : detected after the fact |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Problem Areas | ATC Human Performance Flight Crew Human Performance |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
On descent into montreal (cyul) we were instructed to descend to FL240. Then we received a misinterpreted clearance of maintain FL240, cross franx at FL160. The controller advised us that he said anticipate crossing franx at FL160. He questioned us as we were descending through FL225. There was no conflict with other aircraft. The problem arose with non standard terminology from the canadian controller and our continuing the descent when we were unsure of exactly what the controller wanted. We phoned the ATC supervisor when we were on the ground, as requested, to tell him our position. He did not seem like he would pursue the occurrence. Contributing factors involved: non standard controller terminology. French/canadian accent making it hard to understand controller's directions. Crew not questioning an ambiguous instruction. Poor crew communication.
Original NASA ASRS Text
Title: AN LR35 ATX PIC LEAVES HIS ASSIGNED ALT WHEN THE CREW MISUNDERSTANDS THE CLRNC AS AN 'ANTICIPATE' RATHER THAN ACTUALLY BEING CLRED FOR A SPECIFIC ALT OVER FRANX, PQ.
Narrative: ON DSCNT INTO MONTREAL (CYUL) WE WERE INSTRUCTED TO DSND TO FL240. THEN WE RECEIVED A MISINTERPRETED CLRNC OF MAINTAIN FL240, CROSS FRANX AT FL160. THE CTLR ADVISED US THAT HE SAID ANTICIPATE XING FRANX AT FL160. HE QUESTIONED US AS WE WERE DSNDING THROUGH FL225. THERE WAS NO CONFLICT WITH OTHER ACFT. THE PROB AROSE WITH NON STANDARD TERMINOLOGY FROM THE CANADIAN CTLR AND OUR CONTINUING THE DSCNT WHEN WE WERE UNSURE OF EXACTLY WHAT THE CTLR WANTED. WE PHONED THE ATC SUPVR WHEN WE WERE ON THE GND, AS REQUESTED, TO TELL HIM OUR POS. HE DID NOT SEEM LIKE HE WOULD PURSUE THE OCCURRENCE. CONTRIBUTING FACTORS INVOLVED: NON STANDARD CTLR TERMINOLOGY. FRENCH/CANADIAN ACCENT MAKING IT HARD TO UNDERSTAND CTLR'S DIRECTIONS. CREW NOT QUESTIONING AN AMBIGUOUS INSTRUCTION. POOR CREW COM.
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.