Narrative:

I took off from bistate airport accompanied by (name of passenger, pilot license cfii), sr. Editor of magazine, for a demonstration flight of the only small aircraft motorglider in the country in anticipation of a feature article. We departed the area to the northeast planning to climb above the broken cloud layer for airwork. The plane was equipped with a (brand) GPS and (brand) 3000 moving map display. Leaving the airport air traffic area, we contacted st louis approach for advisories. The controller informed us our mode C readout indicated our altitude was 4800 ft. Our GPS/(brand) showed us under a 4500 ft floor and our altimeter indicated 4400 ft. In fact, we had purposely leveled at 4400 ft to be below the TCA. The controller directed an air carrier medium large transport to turn south to avoid a conflict. The medium large transport was below us and reported his altitude as 4500 ft. The controller gave us the barometer setting much higher than our setting -- we had the wrong barometer setting. Although using a checklist I either set the wrong value in prior to takeoff or changed it inadvertently while caging the ADI which took a lot of effort -- pulling and tugging on the knob immediately adjacent to the brand altimeter. In any event, I took off with the barometer setting 400 ft low, either due to oversight or because it 'looked right' to takeoff with the altimeter at 0 elevation (which is customary for glider operations). The second altimeter is currently calibrated in meters and was not being used.

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Original NASA ASRS Text

Title: PLT OF SMA MOTORIZED GLIDER INADVERTENTLY ENTERED THE TCA DUE TO AN INCORRECT ALTIMETER SETTING.

Narrative: I TOOK OFF FROM BISTATE ARPT ACCOMPANIED BY (NAME OF PAX, PLT LICENSE CFII), SR. EDITOR OF MAGAZINE, FOR A DEMO FLT OF THE ONLY SMA MOTORGLIDER IN THE COUNTRY IN ANTICIPATION OF A FEATURE ARTICLE. WE DEPARTED THE AREA TO THE NE PLANNING TO CLB ABOVE THE BROKEN CLOUD LAYER FOR AIRWORK. THE PLANE WAS EQUIPPED WITH A (BRAND) GPS AND (BRAND) 3000 MOVING MAP DISPLAY. LEAVING THE ARPT ATA, WE CONTACTED ST LOUIS APCH FOR ADVISORIES. THE CTLR INFORMED US OUR MODE C READOUT INDICATED OUR ALT WAS 4800 FT. OUR GPS/(BRAND) SHOWED US UNDER A 4500 FT FLOOR AND OUR ALTIMETER INDICATED 4400 FT. IN FACT, WE HAD PURPOSELY LEVELED AT 4400 FT TO BE BELOW THE TCA. THE CTLR DIRECTED AN ACR MLG TO TURN S TO AVOID A CONFLICT. THE MLG WAS BELOW US AND RPTED HIS ALT AS 4500 FT. THE CTLR GAVE US THE BAROMETER SETTING MUCH HIGHER THAN OUR SETTING -- WE HAD THE WRONG BAROMETER SETTING. ALTHOUGH USING A CHKLIST I EITHER SET THE WRONG VALUE IN PRIOR TO TKOF OR CHANGED IT INADVERTENTLY WHILE CAGING THE ADI WHICH TOOK A LOT OF EFFORT -- PULLING AND TUGGING ON THE KNOB IMMEDIATELY ADJACENT TO THE BRAND ALTIMETER. IN ANY EVENT, I TOOK OFF WITH THE BAROMETER SETTING 400 FT LOW, EITHER DUE TO OVERSIGHT OR BECAUSE IT 'LOOKED RIGHT' TO TKOF WITH THE ALTIMETER AT 0 ELEVATION (WHICH IS CUSTOMARY FOR GLIDER OPS). THE SECOND ALTIMETER IS CURRENTLY CALIBRATED IN METERS AND WAS NOT BEING USED.

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.