lml@lancaironline.net Mailing List Archive

<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> In a message dated 10/5/0 10:24:55 PM, you wrote: <<I finally used the heated pitot, but changed the static to the locations recommended by Lancair on both sides of the airplane. IAS is now accurate and the altimeter is accurate and steady. >> Scott - The error you are describing is called "position error" and is the difference in static pressure at the static port compared to the acutal ambient pressure in the air through which the airplane is flying. I think you know all this. We (Air Force Flight Test Center) measured this error not by IAS errors, but by indicated altitude errors, since a pressure error shows up much bigger on the altimeter rather than on the airspeed indicator. We then used mathematical formulas to transform the altitude error into an airspeed error. Of course, in those days we didn't have GPS for groundspeed measurements.... - Rob Wolf LML website: http://www.olsusa.com/Users/Mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com.