 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A B737-700 flight crew is told to climb back to FL370 after leveling at FL350 and just entering the control area at marte with mmid, first officer.
| Attributes | |
| ACN | 472930 |
| Time | |
| Date | 200005 |
| Day | Tue |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | intersection : marte |
| State Reference | FO |
| Altitude | msl bound lower : 35000 msl bound upper : 37000 |
| Environment | |
| Flight Conditions | VMC |
| Weather Elements | Turbulence |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : mmid.artcc artcc : zhu.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | B737-700 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other |
| Flight Phase | cruise : enroute altitude change |
| Route In Use | enroute : other oceanic enroute airway : ns.airway |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 220 flight time total : 15000 flight time type : 3000 |
| ASRS Report | 472930 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp pilot : multi engine |
| Experience | flight time last 90 days : 245 flight time total : 11500 |
| ASRS Report | 473105 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude inflight encounter : turbulence other anomaly other |
| Independent Detector | other controllera |
| Resolutory Action | controller : issued new clearance controller : issued advisory flight crew : returned to original clearance |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Problem Areas | ATC Human Performance Airspace Structure Environmental Factor Flight Crew Human Performance |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Deviation Inter Facility Coordination Failure |
Narrative:
At XY25Z, houston oceanic called us with this clearance (frequency 132.65): 'maintain FL370 until marte, then descend to FL350.' he had previously asked if we could make FL390, and we advised 'unable.' shortly after, he gave us the above clearance, stating that it was a merida center's request. I figured we had a conflict in merida's airspace at FL370, so at marte, I contacted merida center and gave them a non radar position report, clearly stating we were descending to FL350. This was at XY48Z. At XY51Z, I reported level FL350. At XY52Z, merida called and said we were not cleared to FL350, and that we were to climb to FL370. We complied immediately. No traffic conflicts noted. I should have asked merida to confirm the descent clearance. That would have cleared it all up. However, there was no reason to suspect that the clearance was not valid. Such clrncs are issued regularly over the gulf of mexico. Supplemental information from acn 473105: we told merida we were out of FL370 to FL350. Merida center didn't seem to have any problem with our clearance and gave us a ride report at FL350 of light turbulence. After leveling at FL350, merida center called and said we were not cleared to FL350. Human performance affecting these factors was the language barrier from us as a crew with merida center, and ZHU with merida center.
Original NASA ASRS Text
Title: A B737-700 FLC IS TOLD TO CLB BACK TO FL370 AFTER LEVELING AT FL350 AND JUST ENTERING THE CTL AREA AT MARTE WITH MMID, FO.
Narrative: AT XY25Z, HOUSTON OCEANIC CALLED US WITH THIS CLRNC (FREQ 132.65): 'MAINTAIN FL370 UNTIL MARTE, THEN DSND TO FL350.' HE HAD PREVIOUSLY ASKED IF WE COULD MAKE FL390, AND WE ADVISED 'UNABLE.' SHORTLY AFTER, HE GAVE US THE ABOVE CLRNC, STATING THAT IT WAS A MERIDA CTR'S REQUEST. I FIGURED WE HAD A CONFLICT IN MERIDA'S AIRSPACE AT FL370, SO AT MARTE, I CONTACTED MERIDA CTR AND GAVE THEM A NON RADAR POS RPT, CLRLY STATING WE WERE DSNDING TO FL350. THIS WAS AT XY48Z. AT XY51Z, I RPTED LEVEL FL350. AT XY52Z, MERIDA CALLED AND SAID WE WERE NOT CLRED TO FL350, AND THAT WE WERE TO CLB TO FL370. WE COMPLIED IMMEDIATELY. NO TFC CONFLICTS NOTED. I SHOULD HAVE ASKED MERIDA TO CONFIRM THE DSCNT CLRNC. THAT WOULD HAVE CLRED IT ALL UP. HOWEVER, THERE WAS NO REASON TO SUSPECT THAT THE CLRNC WAS NOT VALID. SUCH CLRNCS ARE ISSUED REGULARLY OVER THE GULF OF MEXICO. SUPPLEMENTAL INFO FROM ACN 473105: WE TOLD MERIDA WE WERE OUT OF FL370 TO FL350. MERIDA CTR DIDN'T SEEM TO HAVE ANY PROB WITH OUR CLRNC AND GAVE US A RIDE RPT AT FL350 OF LIGHT TURB. AFTER LEVELING AT FL350, MERIDA CTR CALLED AND SAID WE WERE NOT CLRED TO FL350. HUMAN PERFORMANCE AFFECTING THESE FACTORS WAS THE LANGUAGE BARRIER FROM US AS A CREW WITH MERIDA CTR, AND ZHU WITH MERIDA CTR.
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.