Narrative:

The filed altitude for the flight was FL180. During the climb the jax center advised that FL180 was unusable and 16000 was assigned. The copilot seat occupant (non pilot) was asking questions regarding the right engine. The prop governor was not keeping the rpm on the right engine constant and I was pointing to the right engine showing where the governor was located. This airplane does not have an altitude alerter system or even altitude reminder. My flying for the last 15 years has been part 121 air carrier with the above equipment with the addition of another pilot. As I passed 15000; I called 15 for 16. As I was explaining and looking at the right engine; center called asking for my altitude. I glanced at the right altimeter; which was not set prior to takeoff and advised 16500. I immediately began a descent but my altimeter showed 16200. We had a 300-400 difference between altimeters due to the fact the right one was not set prior departure. Leveled off at 16000 MSL; and was advised that I was still indicating 16300. Atlanta center reported later in the flight that it was indicating 16300 one moment and 16000 the next. I switched to transponder/encoder to #1 and it did not have this discrepancy. There are several causal factors here. Not having an altitude alerter; not being used to the airplane; not working in a crew environment when that is what I am used to; and distraction by a passenger all contributed to the excursion above the cleared altitude. The deviation was no more than 200-300 ft based on my altimeter; but if not asked by center; the climb may have continued further.

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Original NASA ASRS Text

Title: Distractions and failure to set the altimeter prior to takeoff result in an altitude deviation for a BE90 single pilot.

Narrative: The filed altitude for the flight was FL180. During the climb the Jax Center advised that FL180 was unusable and 16000 was assigned. The copilot seat occupant (non pilot) was asking questions regarding the right engine. The prop governor was not keeping the rpm on the right engine constant and I was pointing to the right engine showing where the governor was located. This airplane does not have an altitude alerter system or even altitude reminder. My flying for the last 15 years has been Part 121 air carrier with the above equipment with the addition of another pilot. As I passed 15000; I called 15 for 16. As I was explaining and looking at the right engine; Center called asking for my altitude. I glanced at the right altimeter; which was not set prior to takeoff and advised 16500. I immediately began a descent but my altimeter showed 16200. We had a 300-400 difference between altimeters due to the fact the right one was not set prior departure. Leveled off at 16000 MSL; and was advised that I was still indicating 16300. Atlanta Center reported later in the flight that it was indicating 16300 one moment and 16000 the next. I switched to transponder/encoder to #1 and it did not have this discrepancy. There are several causal factors here. Not having an altitude alerter; not being used to the airplane; not working in a crew environment when that is what I am used to; and distraction by a passenger all contributed to the excursion above the cleared altitude. The deviation was no more than 200-300 FT based on my altimeter; but if not asked by center; the climb may have continued further.

Data retrieved from NASA's ASRS site as of April 2012 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.