 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
En route, climbing twin cessna overshoots assigned altitude, is reclred to new altitude, but for unknown reason, descends back to initially assigned altitude and conflicts with other en route air carrier.
| Attributes | |
| ACN | 458694 |
| Time | |
| Date | 199912 |
| Day | Wed |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| State Reference | OK |
| Altitude | msl bound lower : 21000 msl bound upper : 23000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zfw.artcc |
| Operator | general aviation : personal |
| Make Model Name | Cessna Twin Piston Undifferentiated or Other Model |
| Operating Under FAR Part | Part 91 |
| Flight Phase | cruise : enroute altitude change |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : zfw.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 119 |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | pilot : instrument |
| Experience | controller non radar : 3 controller radar : 30 controller time certified in position1 : 30 flight time total : 3000 |
| ASRS Report | 458694 |
| Person 2 | |
| Affiliation | other |
| Function | flight crew : single pilot |
| Qualification | pilot : multi engine pilot : instrument |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance |
| Independent Detector | atc equipment : conflict alert other controllera |
| Resolutory Action | controller : issued new clearance flight crew : returned to original clearance |
| Consequence | faa : investigated |
| Miss Distance | horizontal : 24750 vertical : 300 |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance ATC Human Performance |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Aircraft #1 was climbing to FL230 on initial contact which I amended to FL210 and received an acknowledgement. Aircraft #2 was on a converging route with aircraft #1 at FL220. About 6 mins later, I observed the mode C of aircraft #1 at FL228 climbing. I asked aircraft #1 his altitude. He replied FL227. At this time I determined I did not want aircraft #1 to descend back through aircraft #2 and still had sufficient time to provide approved separation at FL230. Therefore, I assigned aircraft #1 FL230 which was reported level by aircraft #1 without a loss of separation. For unknown reason, aircraft #1 mode C began to descend, which caused a loss of separation.
Original NASA ASRS Text
Title: ENRTE, CLBING TWIN CESSNA OVERSHOOTS ASSIGNED ALT, IS RECLRED TO NEW ALT, BUT FOR UNKNOWN REASON, DSNDS BACK TO INITIALLY ASSIGNED ALT AND CONFLICTS WITH OTHER ENRTE ACR.
Narrative: ACFT #1 WAS CLBING TO FL230 ON INITIAL CONTACT WHICH I AMENDED TO FL210 AND RECEIVED AN ACKNOWLEDGEMENT. ACFT #2 WAS ON A CONVERGING RTE WITH ACFT #1 AT FL220. ABOUT 6 MINS LATER, I OBSERVED THE MODE C OF ACFT #1 AT FL228 CLBING. I ASKED ACFT #1 HIS ALT. HE REPLIED FL227. AT THIS TIME I DETERMINED I DID NOT WANT ACFT #1 TO DSND BACK THROUGH ACFT #2 AND STILL HAD SUFFICIENT TIME TO PROVIDE APPROVED SEPARATION AT FL230. THEREFORE, I ASSIGNED ACFT #1 FL230 WHICH WAS RPTED LEVEL BY ACFT #1 WITHOUT A LOSS OF SEPARATION. FOR UNKNOWN REASON, ACFT #1 MODE C BEGAN TO DSND, WHICH CAUSED A LOSS OF SEPARATION.
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.