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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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A widebody transport crew while initiating an ATC requested descent from FL350 to FL330, were then queried by ATC asking if they were still at the original 35000 ft altitude.
| Attributes | |
| ACN | 538147 |
| Time | |
| Date | 200201 |
| Day | Thu |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | navaid : sjn.vortac |
| State Reference | AZ |
| Altitude | msl bound lower : 34600 msl bound upper : 35000 |
| Environment | |
| Flight Conditions | Mixed |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zab.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | Widebody, Low Wing, 3 Turbojet Eng |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise : enroute altitude change |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : zab.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp pilot : instrument pilot : flight engineer pilot : multi engine |
| Experience | flight time last 90 days : 200 flight time total : 8000 flight time type : 600 |
| ASRS Report | 538147 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance |
| Independent Detector | atc equipment other atc equipment : radar other controllera |
| Resolutory Action | controller : issued advisory controller : issued new clearance |
| Consequence | faa : reviewed incident with flight crew |
| Miss Distance | horizontal : 4000 vertical : 2000 |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance ATC Human Performance |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Intra Facility Coordination Failure |
Narrative:
ATC called to advise of need to change altitude due to slower traffic ahead. We chose to descend to FL310. ATC cleared us to FL330 and then called traffic at FL330 at 15 mi. We read back 'cleared to FL330' and began descent. About 400 ft in descent ATC called and asked if we were lined at FL350. No, we answered. ATC then gave immediate instructions to maintain FL350 and called out traffic. At no time did I hear ATC instruct us to maintain FL350. I heard that we could expect lower later, but made no specific reference to any aircraft.
Original NASA ASRS Text
Title: A WDB CREW WHILE INITIATING AN ATC REQUESTED DSCNT FROM FL350 TO FL330, WERE THEN QUERIED BY ATC ASKING IF THEY WERE STILL AT THE ORIGINAL 35000 FT ALT.
Narrative: ATC CALLED TO ADVISE OF NEED TO CHANGE ALT DUE TO SLOWER TFC AHEAD. WE CHOSE TO DSND TO FL310. ATC CLRED US TO FL330 AND THEN CALLED TFC AT FL330 AT 15 MI. WE READ BACK 'CLRED TO FL330' AND BEGAN DSCNT. ABOUT 400 FT IN DSCNT ATC CALLED AND ASKED IF WE WERE LINED AT FL350. NO, WE ANSWERED. ATC THEN GAVE IMMEDIATE INSTRUCTIONS TO MAINTAIN FL350 AND CALLED OUT TFC. AT NO TIME DID I HEAR ATC INSTRUCT US TO MAINTAIN FL350. I HEARD THAT WE COULD EXPECT LOWER LATER, BUT MADE NO SPECIFIC REF TO ANY ACFT.
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.