Narrative:

While descending from 8500 ft MSL and in radio and radar contact flight following with alb approach, I misread my altimeter and momentarily leveled off at which I thought and reported as 4500 ft but was in fact 5400 ft as approach control noticed by altitude reporting transponder. They called traffic for me at 1 O'clock, eastbound, 5500 ft. I saw the reported traffic and notified approach of my misreading the altimeter. I should have asked for a clearing radar vector. I may have been affected by the high altitude (8500 ft MSL, 56 degrees F, altimeter 30.00). I continued descent for landing runway 1 alb. ATC, when providing services, might suggest a clearing vector when in their view a traffic conflict is in progress. I created the problem by misreading my altimeter and I'm thankful for the TA that prevented a greater problem, but a better service would have been to suggest a radar vector or clearing turn away from the traffic, if in their view our flts were in peril. I know flight following is a voluntary service, but it sure is essential in high traffic areas. I was not in class C at the time of the problem. Excellent visibility and I was grateful I was looking out.

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Original NASA ASRS Text

Title: PLT OF A KATANA ON FLT FOLLOWING IN DSCNT MISREADS ALTIMETER AND LEVELS OFF TOO HIGH. APCH CALLS TFC WHICH IS SIGHTED, BUT CLOSE PROX.

Narrative: WHILE DSNDING FROM 8500 FT MSL AND IN RADIO AND RADAR CONTACT FLT FOLLOWING WITH ALB APCH, I MISREAD MY ALTIMETER AND MOMENTARILY LEVELED OFF AT WHICH I THOUGHT AND RPTED AS 4500 FT BUT WAS IN FACT 5400 FT AS APCH CTL NOTICED BY ALT RPTING XPONDER. THEY CALLED TFC FOR ME AT 1 O'CLOCK, EBOUND, 5500 FT. I SAW THE RPTED TFC AND NOTIFIED APCH OF MY MISREADING THE ALTIMETER. I SHOULD HAVE ASKED FOR A CLRING RADAR VECTOR. I MAY HAVE BEEN AFFECTED BY THE HIGH ALT (8500 FT MSL, 56 DEGS F, ALTIMETER 30.00). I CONTINUED DSCNT FOR LNDG RWY 1 ALB. ATC, WHEN PROVIDING SVCS, MIGHT SUGGEST A CLRING VECTOR WHEN IN THEIR VIEW A TFC CONFLICT IS IN PROGRESS. I CREATED THE PROB BY MISREADING MY ALTIMETER AND I'M THANKFUL FOR THE TA THAT PREVENTED A GREATER PROB, BUT A BETTER SVC WOULD HAVE BEEN TO SUGGEST A RADAR VECTOR OR CLRING TURN AWAY FROM THE TFC, IF IN THEIR VIEW OUR FLTS WERE IN PERIL. I KNOW FLT FOLLOWING IS A VOLUNTARY SVC, BUT IT SURE IS ESSENTIAL IN HIGH TFC AREAS. I WAS NOT IN CLASS C AT THE TIME OF THE PROB. EXCELLENT VISIBILITY AND I WAS GRATEFUL I WAS LOOKING OUT.

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.