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An airbus A320 flight crew descended below the assigned altitude rather than maintain the assigned airspeed near msp. At the handoff point the aircraft was above that sector's altitude.
| Attributes | |
| ACN | 443994 |
| Time | |
| Date | 199907 |
| Day | Sun |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : msp.airport |
| State Reference | MN |
| Altitude | msl bound lower : 27000 msl bound upper : 29000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zmp.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | A320 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other |
| Flight Phase | cruise : enroute altitude change |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 160 flight time total : 15000 flight time type : 160 |
| ASRS Report | 443994 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 230 flight time total : 10000 flight time type : 300 |
| ASRS Report | 444150 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude non adherence : clearance |
| Independent Detector | other controllera |
| Resolutory Action | controller : issued new clearance none taken : detected after the fact |
| Supplementary | |
| Problem Areas | ATC Human Performance Flight Crew Human Performance |
| Primary Problem | Ambiguous |
| Air Traffic Incident | Inter Facility Coordination Failure |
Narrative:
I had left the flight deck to use bathroom, we were approaching msp airport at cruise FL290. Upon return from bathroom, the center called and asked our altitude. I reported we were just leveling at FL270. The controller stated he had not authorized FL270. The first officer then took radio and said to the controller that on the frequency change he had been instructed to descend to FL270. The controller then stated your clearance was to maintain 270 KTS. The first officer then stated to the controller that his clearance was to maintain FL270, at which time he had stated maintain FL270 leaving FL290 for FL270. We then got another frequency change, at which I stated FL270, 270 KTS. This controller questioned my altitude. I asked him if there was a problem. He said 'stand by.' he then came back and said no problem, the previous controller should have descended us to FL230 as his airspace started at FL230. It's a center coordination thing, no problem. To solve these kinds of miscoms, we need to distinguish between flight level and maintain speed -- not just maintain 270. Supplemental information from acn 444150: I, first officer, checked in with ZMP at FL290. He cleared me to FL270 and I acknowledged and read back FL270.
Original NASA ASRS Text
Title: AN AIRBUS A320 FLC DSNDED BELOW THE ASSIGNED ALT RATHER THAN MAINTAIN THE ASSIGNED AIRSPD NEAR MSP. AT THE HDOF POINT THE ACFT WAS ABOVE THAT SECTOR'S ALT.
Narrative: I HAD LEFT THE FLT DECK TO USE BATHROOM, WE WERE APCHING MSP ARPT AT CRUISE FL290. UPON RETURN FROM BATHROOM, THE CTR CALLED AND ASKED OUR ALT. I RPTED WE WERE JUST LEVELING AT FL270. THE CTLR STATED HE HAD NOT AUTHORIZED FL270. THE FO THEN TOOK RADIO AND SAID TO THE CTLR THAT ON THE FREQ CHANGE HE HAD BEEN INSTRUCTED TO DSND TO FL270. THE CTLR THEN STATED YOUR CLRNC WAS TO MAINTAIN 270 KTS. THE FO THEN STATED TO THE CTLR THAT HIS CLRNC WAS TO MAINTAIN FL270, AT WHICH TIME HE HAD STATED MAINTAIN FL270 LEAVING FL290 FOR FL270. WE THEN GOT ANOTHER FREQ CHANGE, AT WHICH I STATED FL270, 270 KTS. THIS CTLR QUESTIONED MY ALT. I ASKED HIM IF THERE WAS A PROB. HE SAID 'STAND BY.' HE THEN CAME BACK AND SAID NO PROB, THE PREVIOUS CTLR SHOULD HAVE DSNDED US TO FL230 AS HIS AIRSPACE STARTED AT FL230. IT'S A CTR COORD THING, NO PROB. TO SOLVE THESE KINDS OF MISCOMS, WE NEED TO DISTINGUISH BTWN FLT LEVEL AND MAINTAIN SPD -- NOT JUST MAINTAIN 270. SUPPLEMENTAL INFO FROM ACN 444150: I, FO, CHKED IN WITH ZMP AT FL290. HE CLRED ME TO FL270 AND I ACKNOWLEDGED AND READ BACK FL270.
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.