Narrative:

Hot, turbulent, busy day at las. Waited 15 mins prior to takeoff. Very busy with ATC, vectors, altitude, etc. I got distraction with radios and passenger, climbed through assigned altitude of 4000 ft. Was still climbing when las departure told me to stop at 4500 ft MSL (I was at 4400 ft at that time). As far as I know, there were no traffic conflicts. No real excuse, I just got distraction and forgot altitude restrs. Lessons: write everything down on lap pad, refer to it frequently, don't let distrs affect you following clrncs.

Google
 

Original NASA ASRS Text

Title: A PVT INST RATED PLT FLYING A BE33 NEAR LAS FAILS TO MAINTAIN ALT AS ASSIGNED BY ATC.

Narrative: HOT, TURBULENT, BUSY DAY AT LAS. WAITED 15 MINS PRIOR TO TKOF. VERY BUSY WITH ATC, VECTORS, ALT, ETC. I GOT DISTR WITH RADIOS AND PAX, CLBED THROUGH ASSIGNED ALT OF 4000 FT. WAS STILL CLBING WHEN LAS DEP TOLD ME TO STOP AT 4500 FT MSL (I WAS AT 4400 FT AT THAT TIME). AS FAR AS I KNOW, THERE WERE NO TFC CONFLICTS. NO REAL EXCUSE, I JUST GOT DISTR AND FORGOT ALT RESTRS. LESSONS: WRITE EVERYTHING DOWN ON LAP PAD, REFER TO IT FREQUENTLY, DON'T LET DISTRS AFFECT YOU FOLLOWING CLRNCS.

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.