Narrative:

I received and acknowledged VFR clearance from ground control (normally would have been clearance delivery, but I neglected to call them first and the ground controller was very accommodating), including altitude restr of 1500 ft or below until advised otherwise. I taxied to active runway 10L, contacted tower ready for takeoff, and was advised to hold short. While waiting, I thought about the strong winds and windshear that I had experienced on landing 20 mins earlier and that was being reported by subsequent landing aircraft. I anticipated a left downwind departure, since that was how the controllers had vectored me in for landing and since that would keep me out of the way of the landing and departing jets using runways 10L&right. When cleared for takeoff after a delay of a few mins for other aircraft, I was instructed to maintain runway heading. This took me out of my mental mindset of downwind departure, so I completely forgot about the altitude restr that had been given to me prior to taxi several mins earlier. I blew past my not-to-exceed altitude by 400 ft when the alert tower controller asked me what my altitude was. When I told him I was at 1900 ft and climbing, he reminded me about my altitude restr of 1500 ft. I apologized, immediately arrested my climb and began a descent back down to 1500 ft. This was a potentially dangerous situation, since the airport I was departing from is very busy including jet traffic and radio station traffic spotted that frequently operate at 2000 ft. I believe that I forgot about my altitude restr because of the time between receiving that part of my departure clearance and my takeoff roll, because of the distraction of high winds and windshear, and because of the fact that the aircraft I was flying was more complex than the aircraft I usually fly.; also, while I feel comfortable operating in and out of high density airports such as this one, I hadn't done so in a while. Nonetheless, the oversight was mine and the simple act of writing down even such a simple VFR clearance such as this one might have prevented my altitude excursion.

Google
 

Original NASA ASRS Text

Title: PLT DEPARTING PDX FORGETS TO LEVEL OFF AT 1500 FT ON RWY HDG.

Narrative: I RECEIVED AND ACKNOWLEDGED VFR CLRNC FROM GND CTL (NORMALLY WOULD HAVE BEEN CLRNC DELIVERY, BUT I NEGLECTED TO CALL THEM FIRST AND THE GND CTLR WAS VERY ACCOMMODATING), INCLUDING ALT RESTR OF 1500 FT OR BELOW UNTIL ADVISED OTHERWISE. I TAXIED TO ACTIVE RWY 10L, CONTACTED TWR READY FOR TKOF, AND WAS ADVISED TO HOLD SHORT. WHILE WAITING, I THOUGHT ABOUT THE STRONG WINDS AND WINDSHEAR THAT I HAD EXPERIENCED ON LNDG 20 MINS EARLIER AND THAT WAS BEING RPTED BY SUBSEQUENT LNDG ACFT. I ANTICIPATED A L DOWNWIND DEP, SINCE THAT WAS HOW THE CTLRS HAD VECTORED ME IN FOR LNDG AND SINCE THAT WOULD KEEP ME OUT OF THE WAY OF THE LNDG AND DEPARTING JETS USING RWYS 10L&R. WHEN CLRED FOR TKOF AFTER A DELAY OF A FEW MINS FOR OTHER ACFT, I WAS INSTRUCTED TO MAINTAIN RWY HDG. THIS TOOK ME OUT OF MY MENTAL MINDSET OF DOWNWIND DEP, SO I COMPLETELY FORGOT ABOUT THE ALT RESTR THAT HAD BEEN GIVEN TO ME PRIOR TO TAXI SEVERAL MINS EARLIER. I BLEW PAST MY NOT-TO-EXCEED ALT BY 400 FT WHEN THE ALERT TWR CTLR ASKED ME WHAT MY ALT WAS. WHEN I TOLD HIM I WAS AT 1900 FT AND CLBING, HE REMINDED ME ABOUT MY ALT RESTR OF 1500 FT. I APOLOGIZED, IMMEDIATELY ARRESTED MY CLB AND BEGAN A DSCNT BACK DOWN TO 1500 FT. THIS WAS A POTENTIALLY DANGEROUS SIT, SINCE THE ARPT I WAS DEPARTING FROM IS VERY BUSY INCLUDING JET TFC AND RADIO STATION TFC SPOTTED THAT FREQUENTLY OPERATE AT 2000 FT. I BELIEVE THAT I FORGOT ABOUT MY ALT RESTR BECAUSE OF THE TIME BTWN RECEIVING THAT PART OF MY DEP CLRNC AND MY TKOF ROLL, BECAUSE OF THE DISTR OF HIGH WINDS AND WINDSHEAR, AND BECAUSE OF THE FACT THAT THE ACFT I WAS FLYING WAS MORE COMPLEX THAN THE ACFT I USUALLY FLY.; ALSO, WHILE I FEEL COMFORTABLE OPERATING IN AND OUT OF HIGH DENSITY ARPTS SUCH AS THIS ONE, I HADN'T DONE SO IN A WHILE. NONETHELESS, THE OVERSIGHT WAS MINE AND THE SIMPLE ACT OF WRITING DOWN EVEN SUCH A SIMPLE VFR CLRNC SUCH AS THIS ONE MIGHT HAVE PREVENTED MY ALT EXCURSION.

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.