Narrative:

When I landed at flagstaff I was asked by tower to call ZAB by phone. Upon calling, they said I changed altitudes from 14000' to 12000' west/O permission while flying eastbound east of needles VOR. They also said I descended from 11000' down to 10000' near the oates intersection northbound toward flagstaff ADF. On the first occasion, while communicating with ZLA, I requested lower altitude. ZLA told me to contact ZAB and make my request. Upon contacting ZAB, I requested a lower altitude and received approval. About 10 mins later I was asked what my altitude was. They were apparently not aware I had requested and received approval for a lower altitude. Second occasion, I requested a lower altitude to break out of the clouds while flying northbound from oates intersection while setting up for an ADF approach into flagstaff. I believe I was flying at 11000'. Controller said I couldn't go lower until the airplane ahead of me landed at flagstaff. About 3 mins later the airplane ahead of me reported the airport in sight, cancelled his IFR with center and changed frequencys to flagstaff tower. A few mins later center cleared me to the NDB at flagstaff which I interpreted as clearance for an approach to flagstaff. I started my descent when the controller told me to immediately return to my altitude which I believe was 11000'. He did not allow me to a lower altitude until I was over the airport. Shortly thereafter, as I descended through 10000' I broke out of clouds cancelled my IFR plan and landed. Minimum descent while making ADF approach outbnd is 9400'. I requested a copy of the tape while talking with center by phone.

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Original NASA ASRS Text

Title: GA SMT ALT DEVIATION EXCURSION FROM CLRNC ALT.

Narrative: WHEN I LANDED AT FLAGSTAFF I WAS ASKED BY TWR TO CALL ZAB BY PHONE. UPON CALLING, THEY SAID I CHANGED ALTS FROM 14000' TO 12000' W/O PERMISSION WHILE FLYING EBND E OF NEEDLES VOR. THEY ALSO SAID I DSNDED FROM 11000' DOWN TO 10000' NEAR THE OATES INTXN NBND TOWARD FLAGSTAFF ADF. ON THE FIRST OCCASION, WHILE COMMUNICATING WITH ZLA, I REQUESTED LOWER ALT. ZLA TOLD ME TO CONTACT ZAB AND MAKE MY REQUEST. UPON CONTACTING ZAB, I REQUESTED A LOWER ALT AND RECEIVED APPROVAL. ABOUT 10 MINS LATER I WAS ASKED WHAT MY ALT WAS. THEY WERE APPARENTLY NOT AWARE I HAD REQUESTED AND RECEIVED APPROVAL FOR A LOWER ALT. SECOND OCCASION, I REQUESTED A LOWER ALT TO BREAK OUT OF THE CLOUDS WHILE FLYING NBND FROM OATES INTXN WHILE SETTING UP FOR AN ADF APCH INTO FLAGSTAFF. I BELIEVE I WAS FLYING AT 11000'. CTLR SAID I COULDN'T GO LOWER UNTIL THE AIRPLANE AHEAD OF ME LANDED AT FLAGSTAFF. ABOUT 3 MINS LATER THE AIRPLANE AHEAD OF ME RPTED THE ARPT IN SIGHT, CANCELLED HIS IFR WITH CTR AND CHANGED FREQS TO FLAGSTAFF TWR. A FEW MINS LATER CTR CLRED ME TO THE NDB AT FLAGSTAFF WHICH I INTERPRETED AS CLRNC FOR AN APCH TO FLAGSTAFF. I STARTED MY DSNT WHEN THE CTLR TOLD ME TO IMMEDIATELY RETURN TO MY ALT WHICH I BELIEVE WAS 11000'. HE DID NOT ALLOW ME TO A LOWER ALT UNTIL I WAS OVER THE ARPT. SHORTLY THEREAFTER, AS I DSNDED THROUGH 10000' I BROKE OUT OF CLOUDS CANCELLED MY IFR PLAN AND LANDED. MINIMUM DSNT WHILE MAKING ADF APCH OUTBND IS 9400'. I REQUESTED A COPY OF THE TAPE WHILE TALKING WITH CTR BY PHONE.

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.