Narrative:

Departed adrian, mi, airport VFR around 1500 ft MSL. 2 mi from adrian airport I contacted toledo approach and requested my IFR from adrian, mi, to miles, mi. Toledo approach gave me an IFR clearance which was (I thought) cleared to 3TR via direct gjj direct maintain 5000 ft MSL. I read it back. Climbing through 4500 ft MSL I checked that 5000 ft MSL was still my altitude (I filed 6000 ft). Toledo approach confirmed. About 15-20 mi from adrian, mi, I checked I was still supposed to be with toledo approach, which he said yes. A min later I asked if he still wanted me at 5000 ft MSL. Toledo said he had given me 6000 ft initially and to climb to 6000 ft MSL. I responded climb to 6000 ft MSL without questioning the error. The controller then began running a test on the recorder for the frequency. A few mins later toledo approach called and switched me to kalamazoo approach. I called kalamazoo approach and told them I was level 6000 ft. Kalamazoo said they had nothing on me, my flight plan was gone. I gave them my aircraft prefix PA31 and destination 3TR. I am not sure I did anything wrong other than not hearing 6000 ft MSL as my altitude. I am 90 percent sure I'm right. If not, better communication between controller and pilot is needed! I was at 5000 ft MSL for 15- 20 mi when toledo thought I was at 6000 ft.

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Original NASA ASRS Text

Title: CHARTER PLT WITH EMPTY ACFT MISHEARS ALT ASSIGNMENT, QUERIES APCH CTLR AND IS GIVEN AN AFFIRMATIVE RESPONSE.

Narrative: DEPARTED ADRIAN, MI, ARPT VFR AROUND 1500 FT MSL. 2 MI FROM ADRIAN ARPT I CONTACTED TOLEDO APCH AND REQUESTED MY IFR FROM ADRIAN, MI, TO MILES, MI. TOLEDO APCH GAVE ME AN IFR CLRNC WHICH WAS (I THOUGHT) CLRED TO 3TR VIA DIRECT GJJ DIRECT MAINTAIN 5000 FT MSL. I READ IT BACK. CLBING THROUGH 4500 FT MSL I CHKED THAT 5000 FT MSL WAS STILL MY ALT (I FILED 6000 FT). TOLEDO APCH CONFIRMED. ABOUT 15-20 MI FROM ADRIAN, MI, I CHKED I WAS STILL SUPPOSED TO BE WITH TOLEDO APCH, WHICH HE SAID YES. A MIN LATER I ASKED IF HE STILL WANTED ME AT 5000 FT MSL. TOLEDO SAID HE HAD GIVEN ME 6000 FT INITIALLY AND TO CLB TO 6000 FT MSL. I RESPONDED CLB TO 6000 FT MSL WITHOUT QUESTIONING THE ERROR. THE CTLR THEN BEGAN RUNNING A TEST ON THE RECORDER FOR THE FREQ. A FEW MINS LATER TOLEDO APCH CALLED AND SWITCHED ME TO KALAMAZOO APCH. I CALLED KALAMAZOO APCH AND TOLD THEM I WAS LEVEL 6000 FT. KALAMAZOO SAID THEY HAD NOTHING ON ME, MY FLT PLAN WAS GONE. I GAVE THEM MY ACFT PREFIX PA31 AND DEST 3TR. I AM NOT SURE I DID ANYTHING WRONG OTHER THAN NOT HEARING 6000 FT MSL AS MY ALT. I AM 90 PERCENT SURE I'M RIGHT. IF NOT, BETTER COM BTWN CTLR AND PLT IS NEEDED! I WAS AT 5000 FT MSL FOR 15- 20 MI WHEN TOLEDO THOUGHT I WAS AT 6000 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.