From: Hayes_Press@qmgate.larc.nasa.gov (Hayes N. Press) Organization: Lockheed Engineering and Sciences Company Date: 25 Aug 93 02:53:31 PDT References: 1
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In article <airliners.1993.560@ohare.Chicago.COM> papadopo@cs.utk.edu (Philip Papadopoulos) writes: >I noticed on a recent trip that some MD-80's (MD-88's, too) have >"flattened" tailcones (versus conical ones). Could someone give >me some history on this development. The "flattened" tailcones were designed as a replacement/design change on all MD-80 series aircraft since at least 1986. It was done to decrease fuel comsumption by both decreasing drag at the tail and by the change to the use of more composite material. As far as I know, no airline is actively retrofiting their tailcones but they may replace them with the newer designed one when and if a replacement is needed. >BTW, the flattened and elongated tailcone is very apparent on >American jets, less so on Delta Jets. I saw about 8 Northwest >MD-8x's and none had the flattened cone. All the American Jets >I saw did have the new cone (about 15 examples) and most >(but not all) of the Delta jets had flattened tailcones. The main reason for your observation probably has a lot to do with fleet age and mix. American Airlines has the largest fleet of MD-80's with over 200, and at one time this was the record for the industry of one airline have such a large fleet of one type aircraft. The Northwest aircraft you observed were probably all DC-9 series aircraft and these older models gennerally have not been changed. To the best of my knowledge NW has no MD-80's in its fleet. And Delta falls right in the middle. Speaking only for myself and all standard disclaimers apply. Hayes