Narrative:

Small transport was coming out of maintenance and I had been performing numerous checks to include an automatic-rotation to check the rotor RPM after the changing of 2 of the 4 rotor blades. I called luk tower and asked to stay in left traffic for runway 6 with a block of airspace up to 4000'. They coordinated with cvg approach control and approved my request. I was also told not to go south of luk due to traffic. I climbed to 3500' indicated and entered the automatic-rotation. Tower called and said approach showed me at 4700' and I was told not to go about 4000'. I told them I had gone to 3500' nd entered automatic-rotation and was now descending through 2500' (ind). I checked the copilot's altimeter ad it was the same as mine. Then I looked at the kollsman window and noted the setting of 2905. This was much too low for the current high pressure system in the area. I immediately checked ATIS for the current altimeter setting which was 30.14. There had been bad WX (low pressure system) moving through the area. During the time the aircraft had been down during the last week of continuous maintenance. The aircraft had been run up numerous times during that period. When I got in the aircraft that morning, I remember the altimeter indicating '700' (actually -300'). I moved the altimeter approximately 200' to the field elevation of 483' (actually -517'). By misreading and incorrectly setting the altimeter to field elevation, it was actually 1000' off the correct altitude. When I entered the automatic-rotation at 3500'. I was actually at 4500' MSL. I had checked ATIS several times that day for wind and cloud bases, but for some unknown reason I did not check the altimeter setting. In the future, I will be very aware of the actual altitude setting when using field elevation and use gear care in reading the altimeter.

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Original NASA ASRS Text

Title: ROTARY WINGED SMT EXPERIENCES AN ALT DEVIATION WHILE ON A TEST HOP.

Narrative: SMT WAS COMING OUT OF MAINT AND I HAD BEEN PERFORMING NUMEROUS CHKS TO INCLUDE AN AUTO-ROTATION TO CHK THE ROTOR RPM AFTER THE CHANGING OF 2 OF THE 4 ROTOR BLADES. I CALLED LUK TWR AND ASKED TO STAY IN LEFT TFC FOR RWY 6 WITH A BLOCK OF AIRSPACE UP TO 4000'. THEY COORDINATED WITH CVG APCH CTL AND APPROVED MY REQUEST. I WAS ALSO TOLD NOT TO GO S OF LUK DUE TO TFC. I CLBED TO 3500' INDICATED AND ENTERED THE AUTO-ROTATION. TWR CALLED AND SAID APCH SHOWED ME AT 4700' AND I WAS TOLD NOT TO GO ABOUT 4000'. I TOLD THEM I HAD GONE TO 3500' ND ENTERED AUTO-ROTATION AND WAS NOW DSNDING THROUGH 2500' (IND). I CHKED THE COPLT'S ALTIMETER AD IT WAS THE SAME AS MINE. THEN I LOOKED AT THE KOLLSMAN WINDOW AND NOTED THE SETTING OF 2905. THIS WAS MUCH TOO LOW FOR THE CURRENT HIGH PRESSURE SYS IN THE AREA. I IMMEDIATELY CHKED ATIS FOR THE CURRENT ALTIMETER SETTING WHICH WAS 30.14. THERE HAD BEEN BAD WX (LOW PRESSURE SYS) MOVING THROUGH THE AREA. DURING THE TIME THE ACFT HAD BEEN DOWN DURING THE LAST WK OF CONTINUOUS MAINT. THE ACFT HAD BEEN RUN UP NUMEROUS TIMES DURING THAT PERIOD. WHEN I GOT IN THE ACFT THAT MORNING, I REMEMBER THE ALTIMETER INDICATING '700' (ACTUALLY -300'). I MOVED THE ALTIMETER APPROX 200' TO THE FIELD ELEVATION OF 483' (ACTUALLY -517'). BY MISREADING AND INCORRECTLY SETTING THE ALTIMETER TO FIELD ELEVATION, IT WAS ACTUALLY 1000' OFF THE CORRECT ALT. WHEN I ENTERED THE AUTO-ROTATION AT 3500'. I WAS ACTUALLY AT 4500' MSL. I HAD CHKED ATIS SEVERAL TIMES THAT DAY FOR WIND AND CLOUD BASES, BUT FOR SOME UNKNOWN REASON I DID NOT CHK THE ALTIMETER SETTING. IN THE FUTURE, I WILL BE VERY AWARE OF THE ACTUAL ALT SETTING WHEN USING FIELD ELEVATION AND USE GEAR CARE IN READING THE ALTIMETER.

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.