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An atx pilot leaves his assigned altitude prematurely after receiving a clearance for a 'VFR on top' after ila, ca.
| Attributes | |
| ACN | 457060 |
| Time | |
| Date | 199912 |
| Day | Tue |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| State Reference | CA |
| Altitude | msl bound lower : 8000 msl bound upper : 8500 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zoa.artcc |
| Operator | common carrier : air taxi |
| Make Model Name | Caravan 1 208A |
| Operating Under FAR Part | Part 135 |
| Flight Phase | cruise : level |
| Route In Use | enroute : direct |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air taxi |
| Function | flight crew : single pilot |
| Qualification | pilot : commercial pilot : multi engine pilot : instrument |
| Experience | flight time last 90 days : 50 flight time total : 3000 flight time type : 790 |
| ASRS Report | 457060 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude non adherence : clearance |
| Independent Detector | atc equipment other atc equipment : radar -- mode c other controllera |
| Resolutory Action | controller : issued new clearance controller : issued advisory |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
On an IFR flight plan from smf to acv maintaining 8000 ft, after being handed off from sacramento approach to ZOA, I checked in with ZOA as 'oak hills 1234, 8000 ft with request.' ZOA: '1234, go ahead with request.' 1234: currently VFR on top requesting VFR on top after williams (ila) direct yager intersection, direct. ZOA: 1234 cleared VFR on top, after williams (ila), direct yager intersection, direct. I read back the clearance and proceeded to climb to 8500 ft approximately 10 mi southeast of williams (ila) VOR. Upon reaching 8500 ft, ZOA asked about my altitude. I told him 8500 ft. He replied he cleared me 'after williams' VFR on top. A little bit later ZOA cleared me to maintain VFR on top. Problem was simple human misunderstanding. To prevent recurrence, I could have simplified my request to 'VFR on top direct yager intersection.' this left a question in my mind as to when the VFR on top started, with the controller's stipulation of after williams.
Original NASA ASRS Text
Title: AN ATX PLT LEAVES HIS ASSIGNED ALT PREMATURELY AFTER RECEIVING A CLRNC FOR A 'VFR ON TOP' AFTER ILA, CA.
Narrative: ON AN IFR FLT PLAN FROM SMF TO ACV MAINTAINING 8000 FT, AFTER BEING HANDED OFF FROM SACRAMENTO APCH TO ZOA, I CHKED IN WITH ZOA AS 'OAK HILLS 1234, 8000 FT WITH REQUEST.' ZOA: '1234, GO AHEAD WITH REQUEST.' 1234: CURRENTLY VFR ON TOP REQUESTING VFR ON TOP AFTER WILLIAMS (ILA) DIRECT YAGER INTXN, DIRECT. ZOA: 1234 CLRED VFR ON TOP, AFTER WILLIAMS (ILA), DIRECT YAGER INTXN, DIRECT. I READ BACK THE CLRNC AND PROCEEDED TO CLB TO 8500 FT APPROX 10 MI SE OF WILLIAMS (ILA) VOR. UPON REACHING 8500 FT, ZOA ASKED ABOUT MY ALT. I TOLD HIM 8500 FT. HE REPLIED HE CLRED ME 'AFTER WILLIAMS' VFR ON TOP. A LITTLE BIT LATER ZOA CLRED ME TO MAINTAIN VFR ON TOP. PROB WAS SIMPLE HUMAN MISUNDERSTANDING. TO PREVENT RECURRENCE, I COULD HAVE SIMPLIFIED MY REQUEST TO 'VFR ON TOP DIRECT YAGER INTXN.' THIS LEFT A QUESTION IN MY MIND AS TO WHEN THE VFR ON TOP STARTED, WITH THE CTLR'S STIPULATION OF AFTER WILLIAMS.
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.