Confusion between pilot and ATC as to whether IFR flight plan was cancelled or not.

Attributes
ACN	131617
Time
Date	198912
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lzu
State Reference	GA
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : atl
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	descent : approach descent other
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 17 flight time total : 500 flight time type : 417
ASRS Report	131617
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : anomaly accepted
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

I was on an IFR flight plan from ctj to lzu nearing lzu, level at 4000'. Atl approach called 'small aircraft X descend and maintain 3000'.' my response was 'descend and maintain 3000', small aircraft X.' the controller called again in 1 min + after I was level at 3000' and said 'small aircraft X gwinnett co airport is 6 NM at your 12:30 position. Report airport in sight and either cancel IFR with me or by phone after landing if we lose radio contact.' my immediate response was 'have airport in sight now small aircraft X.' the controller immediately said 'small aircraft X frequency change approved squawk 1200, good day.' my first error was that while I intended the information that I had the airport in sight to indicate that I was indeed cancelling IFR, I did not say cancel IFR at this time. However, I fully expected to hear ATC say frequency change approved squawk 1200 IFR cancelled at this time. My second error was in not specifically clarifying cancellation. It was obvious to me that approach was looking for me, and now I must exercise the second option the controller gave me, that of calling on the phone to cancel IFR. As I stepped out of the airplane the FBO operator stuck his head out the door and said I had a call. It was the atlanta approach control supervisor who informed me that I had not cancelled my IFR flight plan and wanted me to know and understand how important this is. I told him I had just shut down my engine and was headed inside to call atlanta flight service to cancel IFR 'again' since I had thought ATC understood the first time and the overflt made me aware that ATC did not understand cancellation. I mentioned to the supervisor that it was my understanding of approach control procedures that one would never be released from a squawk code and approach frequency unless one was no longer on a flight plan. This has been on my mind almost to the point of distraction since the incident, therefore, I am sure I will never leave any communication with the possibility of unclear or incorrect interpretation in the future.

Original NASA ASRS Text

Title: CONFUSION BETWEEN PLT AND ATC AS TO WHETHER IFR FLT PLAN WAS CANCELLED OR NOT.

Narrative: I WAS ON AN IFR FLT PLAN FROM CTJ TO LZU NEARING LZU, LEVEL AT 4000'. ATL APCH CALLED 'SMA X DSND AND MAINTAIN 3000'.' MY RESPONSE WAS 'DSND AND MAINTAIN 3000', SMA X.' THE CTLR CALLED AGAIN IN 1 MIN + AFTER I WAS LEVEL AT 3000' AND SAID 'SMA X GWINNETT CO ARPT IS 6 NM AT YOUR 12:30 POSITION. REPORT ARPT IN SIGHT AND EITHER CANCEL IFR WITH ME OR BY PHONE AFTER LNDG IF WE LOSE RADIO CONTACT.' MY IMMEDIATE RESPONSE WAS 'HAVE ARPT IN SIGHT NOW SMA X.' THE CTLR IMMEDIATELY SAID 'SMA X FREQ CHANGE APPROVED SQUAWK 1200, GOOD DAY.' MY FIRST ERROR WAS THAT WHILE I INTENDED THE INFO THAT I HAD THE ARPT IN SIGHT TO INDICATE THAT I WAS INDEED CANCELLING IFR, I DID NOT SAY CANCEL IFR AT THIS TIME. HOWEVER, I FULLY EXPECTED TO HEAR ATC SAY FREQ CHANGE APPROVED SQUAWK 1200 IFR CANCELLED AT THIS TIME. MY SECOND ERROR WAS IN NOT SPECIFICALLY CLARIFYING CANCELLATION. IT WAS OBVIOUS TO ME THAT APCH WAS LOOKING FOR ME, AND NOW I MUST EXERCISE THE SECOND OPTION THE CTLR GAVE ME, THAT OF CALLING ON THE PHONE TO CANCEL IFR. AS I STEPPED OUT OF THE AIRPLANE THE FBO OPERATOR STUCK HIS HEAD OUT THE DOOR AND SAID I HAD A CALL. IT WAS THE ATLANTA APCH CTL SUPVR WHO INFORMED ME THAT I HAD NOT CANCELLED MY IFR FLT PLAN AND WANTED ME TO KNOW AND UNDERSTAND HOW IMPORTANT THIS IS. I TOLD HIM I HAD JUST SHUT DOWN MY ENGINE AND WAS HEADED INSIDE TO CALL ATLANTA FLT SERVICE TO CANCEL IFR 'AGAIN' SINCE I HAD THOUGHT ATC UNDERSTOOD THE FIRST TIME AND THE OVERFLT MADE ME AWARE THAT ATC DID NOT UNDERSTAND CANCELLATION. I MENTIONED TO THE SUPVR THAT IT WAS MY UNDERSTANDING OF APCH CTL PROCS THAT ONE WOULD NEVER BE RELEASED FROM A SQUAWK CODE AND APCH FREQ UNLESS ONE WAS NO LONGER ON A FLT PLAN. THIS HAS BEEN ON MY MIND ALMOST TO THE POINT OF DISTR SINCE THE INCIDENT, THEREFORE, I AM SURE I WILL NEVER LEAVE ANY COMMUNICATION WITH THE POSSIBILITY OF UNCLEAR OR INCORRECT INTERPRETATION IN THE FUTURE.

Data retrieved from NASA's ASRS site as of August 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.