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A light aircraft pilot confused controller's comment about pilot's clearance request, to be the clearance granted. Altitude deviation resulted.
| Attributes | |
| ACN | 304720 |
| Time | |
| Date | 199505 |
| Day | Tue |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : aml |
| State Reference | VA |
| Altitude | msl bound lower : 6700 msl bound upper : 7500 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : iad |
| Operator | general aviation : corporate |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Operating Under FAR Part | Part 91 |
| Flight Phase | descent other |
| Flight Plan | None |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : single pilot |
| Qualification | pilot : instrument pilot : commercial |
| Experience | flight time last 90 days : 50 flight time total : 2000 flight time type : 200 |
| ASRS Report | 304720 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : approach |
| Qualification | controller : radar |
| Events | |
| Anomaly | altitude deviation : overshoot non adherence : clearance other anomaly other |
| Independent Detector | other controllera |
| Resolutory Action | controller : issued new clearance other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Departed 6a6, climbed to 11500 ft direct to fdk. When 45 mi south of iad, contacted dulles approach. Received clearance direct to fdk with a descent to 7500 ft. When descending through approximately 7800 ft, I asked for lower. I understood controller to grant clearance to 5500 ft, with a comment that lower than 5500 ft would not be available until north of iad. While descending through 6700 ft controller asked for altitude. I advised 6700 ft. He advised that he had only issued clearance to 7500 ft. When I asked about the 5500 ft clearance the controller advised that my clearance was only to 7500 ft and that the comment about 5500 ft was that 5500 ft would be available north of iad. Controller then advised that I had clearance to 6500 ft. The remainder of the descent was uneventful. WX was good. Radio reception good. Workload busy for controller, light to moderate for pilot. Phraseology nonstandard. Recommendations: use standard type of IFR clearance phrase such as 'maintain 7500 ft, expect lower in X mi.' my readback was also nonstandard. It should have been nxxx cleared to 5500 ft.
Original NASA ASRS Text
Title: A LIGHT ACFT PLT CONFUSED CTLR'S COMMENT ABOUT PLT'S CLRNC REQUEST, TO BE THE CLRNC GRANTED. ALTDEV RESULTED.
Narrative: DEPARTED 6A6, CLBED TO 11500 FT DIRECT TO FDK. WHEN 45 MI S OF IAD, CONTACTED DULLES APCH. RECEIVED CLRNC DIRECT TO FDK WITH A DSCNT TO 7500 FT. WHEN DSNDING THROUGH APPROX 7800 FT, I ASKED FOR LOWER. I UNDERSTOOD CTLR TO GRANT CLRNC TO 5500 FT, WITH A COMMENT THAT LOWER THAN 5500 FT WOULD NOT BE AVAILABLE UNTIL N OF IAD. WHILE DSNDING THROUGH 6700 FT CTLR ASKED FOR ALT. I ADVISED 6700 FT. HE ADVISED THAT HE HAD ONLY ISSUED CLRNC TO 7500 FT. WHEN I ASKED ABOUT THE 5500 FT CLRNC THE CTLR ADVISED THAT MY CLRNC WAS ONLY TO 7500 FT AND THAT THE COMMENT ABOUT 5500 FT WAS THAT 5500 FT WOULD BE AVAILABLE N OF IAD. CTLR THEN ADVISED THAT I HAD CLRNC TO 6500 FT. THE REMAINDER OF THE DSCNT WAS UNEVENTFUL. WX WAS GOOD. RADIO RECEPTION GOOD. WORKLOAD BUSY FOR CTLR, LIGHT TO MODERATE FOR PLT. PHRASEOLOGY NONSTANDARD. RECOMMENDATIONS: USE STANDARD TYPE OF IFR CLRNC PHRASE SUCH AS 'MAINTAIN 7500 FT, EXPECT LOWER IN X MI.' MY READBACK WAS ALSO NONSTANDARD. IT SHOULD HAVE BEEN NXXX CLRED TO 5500 FT.
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.