Narrative:

I departed john wayne VFR and contacted coast departure control for advisories en route to lake tahoe. When handed off to ZLA, I informed them my proposed altitude would be 12500'. I made a series of climbing 360 degree turns to 12500'. Center called an said to resume my own navigation and would I now be continuing heading north? I confirmed that, but there were large buildups of clouds in that area. I called center a few mins later to advise that I was starting a series of climbing turns to 16500'. They acknowledged and asked if I was using O2. I confirmed that I had been using O2 since 10500' MSL. The clouds and haze to the northwest were a little better, but to the southeast were much more favorable at that altitude. I contacted center that I was changing course to southeast and climbing to 17500' where haze appeared thinner and cloud buildups ended. Over this period of time, I had made several power settings and climb attitude changes. While continuing southeast I was asked by center, 'what is your altitude?' I then realized that I was at 19200', retrimmed the aircraft and started an immediate descent to the appropriate altitude for my southeast heading. Center contacted me and asked that I call them in la after I had landed. At that time I informed center that I would be returning to john wayne airport. I contacted them by phone immediately upon landing. What could have helped my situation might have been an earlier contact by center, workload permitting, in regards to my altitude. I do realize the potential danger of my situation, and have learned from it.

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Original NASA ASRS Text

Title: GA PLT INADVERTENTLY ENTERS ZLA PCA BY CLIMBING ABOVE 18000'.

Narrative: I DEPARTED JOHN WAYNE VFR AND CONTACTED COAST DEP CTL FOR ADVISORIES ENRTE TO LAKE TAHOE. WHEN HANDED OFF TO ZLA, I INFORMED THEM MY PROPOSED ALT WOULD BE 12500'. I MADE A SERIES OF CLBING 360 DEG TURNS TO 12500'. CENTER CALLED AN SAID TO RESUME MY OWN NAV AND WOULD I NOW BE CONTINUING HDG N? I CONFIRMED THAT, BUT THERE WERE LARGE BUILDUPS OF CLOUDS IN THAT AREA. I CALLED CENTER A FEW MINS LATER TO ADVISE THAT I WAS STARTING A SERIES OF CLBING TURNS TO 16500'. THEY ACKNOWLEDGED AND ASKED IF I WAS USING O2. I CONFIRMED THAT I HAD BEEN USING O2 SINCE 10500' MSL. THE CLOUDS AND HAZE TO THE NW WERE A LITTLE BETTER, BUT TO THE SE WERE MUCH MORE FAVORABLE AT THAT ALT. I CONTACTED CENTER THAT I WAS CHANGING COURSE TO SE AND CLBING TO 17500' WHERE HAZE APPEARED THINNER AND CLOUD BUILDUPS ENDED. OVER THIS PERIOD OF TIME, I HAD MADE SEVERAL PWR SETTINGS AND CLB ATTITUDE CHANGES. WHILE CONTINUING SE I WAS ASKED BY CENTER, 'WHAT IS YOUR ALT?' I THEN REALIZED THAT I WAS AT 19200', RETRIMMED THE ACFT AND STARTED AN IMMEDIATE DSNT TO THE APPROPRIATE ALT FOR MY SE HDG. CENTER CONTACTED ME AND ASKED THAT I CALL THEM IN LA AFTER I HAD LANDED. AT THAT TIME I INFORMED CENTER THAT I WOULD BE RETURNING TO JOHN WAYNE ARPT. I CONTACTED THEM BY PHONE IMMEDIATELY UPON LNDG. WHAT COULD HAVE HELPED MY SITUATION MIGHT HAVE BEEN AN EARLIER CONTACT BY CENTER, WORKLOAD PERMITTING, IN REGARDS TO MY ALT. I DO REALIZE THE POTENTIAL DANGER OF MY SITUATION, AND HAVE LEARNED FROM IT.

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.